
"The act of publishing research is an act of intellectual generosity, offering insights and discoveries to the wider world." - Steven Pinker
Publications
Delve into the latest scientific investigations surrounding the multifaceted potential of medicinal plants. These studies explore topics ranging from drug permeability and antimicrobial efficacy enhancement to phytochemical characterisation, offering valuable insights into the diverse therapeutic properties and applications of various medicinal plants in modern pharmacology and herbal medicine.
2020 - Present
2010 - 2019
2000 - 2009
1993 - 1999
2020 - Present
- Haasbroek-Pheiffer, A., Viljoen, A., Steenekamp, J., Chen, W., Hamman, J. 2024. An ex vivo investigation on drug permeability of sheep nasal epithelial tissue membranes from the respiratory and olfactory regions. Current Drug Delivery, 21(1), 115–125. Doi: https://doi.org/10.2174/1567201820666221214105836
- Mapeka, T., Sandasi, M., Ncube, N., Viljoen, A., Van Vuuren, S. 2024. Enhancing the antimicrobial efficacy of common herbs and spices through an optimized polyherbal approach. South African Journal of Botany, 164, 91–99. Doi: https://doi.org/10.1016/j.sajb.2023.11.030
- Haasbroek-Pheiffer, A., Viljoen, A., Steenekamp, J., Chen, W., Hamman, J. 2023. Permeation of phytochemicals of selected psychoactive medicinal plants across excised sheep respiratory and olfactory epithelial tissues. Pharmaceutics, 15(5):1423. Doi: https://doi.org/10.3390/pharmaceutics15051423
- Schripsema,, Augustyn, W., Viljoen, A. 2023. Characterisation of Sclerocarya birrea (marula) seed oil and investigation of the geographical origin by applying similarity calculations, differential NMR and hierarchical cluster analysis. Phytochemical Analysis 34(8): 959–969. Doi: https://doi.org/10.1002/pca.3264
- Orchard, A., Moosa, T., Motala, N., Kamatou, G., Viljoen, A., Van Vuuren, S.V. Commercially available Viola odorata oil, chemical variability and antimicrobial activity. Molecules, 28(4): 1676. Doi: https://doi.org/10.3390/molecules28041676
- Rubegeta, E., Makolo, F., Kamatou, G., Enslin, G., Chaudhar,y S., Sandasi, M., Cunningham A.B., Viljoen A. The African cherry: A review of the botany, traditional uses, phytochemistry, and biological activities of Prunus Africana (Hook.f.) Kalkman. Journal of Ethnopharmacology 305:116004. Doi: https://doi.org/10.1016/j.jep.2022.116004
- Zulfiqar, F., Ali F., Viljoen, A.M., Chittiboyina, A.G., Khan, I.A. 2023. Flavonoid glycosides and ellagic acid cognates from defatted African mango (Irvingia gabonensis) seed kernel. Natural Product Research 37(17): 2878–2887. Doi: https://doi.org/10.1080/14786419.2022.2140151
- Chen, W., Viljoen, A.M. Geraniol – A review update. South African Journal of Botany 150:1205–1219. Doi: https://doi.org/10.1016/j.sajb.2022.09.012
- Anokwuru, C.P., Chen, W., Van Vuuren, S., Combrinck, S., Viljoen, A.M. Bioautography-guided HPTLC–MS as a rapid hyphenated technique for the identification of antimicrobial compounds from selected South African Combretaceae species. Phytochemical Analysis 33(8):1177–1189. Doi: https://doi.org/10.1002/pca.3167
- Boussamba-Digombou, K.J., Sandasi, M., Kamatou, G.P., Van Vuuren, S., Sawicki, R., Fakhar, Z., Viljoen, A.M. Investigating the antituberculosis activity of selected commercial essential oils and identification of active constituents using a biochemometrics approach and in silico modeling. Antibiotics 11(7):948. Doi: https://doi.org/10.3390/antibiotics11070948
- Lim Ah Tock, M., Combrinck, S., Kamatou, G., Chen, W., Van Vuuren, S., Viljoen, A. Antibacterial screening, biochemometric and bioautographic evaluation of the non-volatile bioactive components of three indigenous South African Salvia species. Antibiotics 11(7):901. Doi: https://doi.org/10.3390/antibiotics11070901
- Mapeka, T.M., Sandasi, M., Viljoen, A.M., van Vuuren, S.F. Optimization of antioxidant synergy in a polyherbal combination by experimental design. Molecules 27(13): 4196. Doi: https://doi.org/10.3390/molecules27134196
- Fantoukh, O.I., Wang, Y.H., Parveen, A., Hawwal, M.F., Ali, Z., Al-Hamoud, G.A., Chittiboyina, A.G., Joubert, E., Viljoen, A., Khan, I.A. 2022. Chemical fingerprinting profile and targeted quantitative analysis of phenolic compounds from rooibos tea (Aspalathus linearis) and dietary supplements using UHPLC-PDA-MS. Separations 9(7):159. Doi: https://doi.org/10.3390/separations9070159
- Kasote, D., Bankova, V., Viljoen, A.M. 2022. Propolis: chemical diversity and challenges in quality control. Phytochemistry Reviews 21(6):1887–1911. Doi: https://doi.org/10.1007/s11101-022-09816-1
- Pretorius, E., Mncwangi, N.P., Kabongo, R.M., Chen, W., Vermaak, I., van der Bank, M., Viljoen, A.M. 2022. A quality control perspective on Devil’s claw, Harpagophytum procumbens and H. zeyheri: phytochemical analysis and DNA barcoding. South African Journal of Botany 146:90–100. Doi: https://doi.org/10.1016/j.sajb.2021.09.029
- Mhlongo, F., Cordero-Maldonado, M.L., Crawford, A.D., Katerere, D., Sandasi, M., Hattingh, A.C., Koekemoer, T.C., van de Venter, M., Viljoen, A.M. 2022. Evaluation of the wound healing properties of South African medicinal plants using zebrafish and in vitro Journal of Ethnopharmacology 286:114867. Doi: https://doi.org/10.1016/j.jep.2021.114867
- Gericke, J., Lekhooa, M., Steyn, S.F., Viljoen, A.M., Harvey, B.H. 2022. An acute dose-ranging evaluation of the antidepressant properties of Sceletium tortuosum (Zembrin®) versus escitalopram in the Flinders Sensitive Line rat. Journal of Ethnopharmacology 284: 114550. Doi: https://doi.org/10.1016/j.jep.2021.114550
- Anokwuru, C.P., Makolo, F., Sandasi, M., Tankeu, S.Y., Elisha, I.L., Agoni, C., Combrinck, S., Viljoen, A. Cannabigerol: a bibliometric overview and review of research on an important phytocannabinoid. Phytochemistry Reviews 21:1523–1547. Doi: https://doi.org/10.1007/s11101-021-09794-w
- Peterson, B., Jacobsz, C., Hamman, J., Viljoen, A., Steyn, D. 2022. Pharmacokinetic interactions: The effects of selected herbal extracts on permeation of P-glycoprotein substrate drugs across excised pig intestinal tissue. Journal of HerbMed Pharmacology 11(1):121–130. Doi: https://doi.org/34172/jhp.2022.14
- Rampa, K.M., van de Venter, M., Koekemoer, T.C., Swanepeol, B., Venables., L., Hattingh, A.C., Viljoen, A.M., Kamatou, G.P. 2022 Exploring four South African Croton species for potential anti-inflammatory properties: in vitro activity and toxicity risk assessment. Journal of Ethnopharmacology 282:114596. Doi: https://doi.org/10.1016/j.jep.2021.114596
- Maphanga, V.B., Skalicka-Woźniak, K., Budzynska, B., Skiba, A., Chen, W., Agoni, C., Enslin, G.M., Viljoen, A.M. 2022. Mesembryanthemum tortuosum alkaloids modify anxiety-like behaviour in a zebrafish model. Journal of Ethnopharmacology 290: 115068. Doi: https://doi.org/10.1016/j.jep.2022.115068
- De Rapper, S., Viljoen, A., Van Vuuren, S. 2022. Optimizing the antimicrobial synergism of melaleuca alternifolia (Tea tree) essential oil combinations for application against respiratory related pathogens. Planta Medica, 89(4), pp. 454–463. Doi: https://doi.org/10.1055/a-1947-5680
- Mulaudzi, N., Combrinck, S., Vermaak, I., Joubert, E., Viljoen, A. 2022. High performance thin layer chromatography fingerprinting of rooibos (Aspalathus linearis) and honeybush (Cyclopia genistoides, Cyclopia intermedia and Cyclopia subternata) teas. Journal of Applied Research on Medicinal and Aromatic Plants 30:100378. Doi: https://doi.org/10.1016/j.jarmap.2022.100378
- De Rapper, S.L., Viljoen, A., Van Vuuren, S. 2021. Essential oil blends: The potential of combined use for respiratory tract infections. Antibiotics 10(12): 1517. Doi: https://doi.org/10.3390/antibiotics10121517
- Moremi, M.P., Makolo, F., Viljoen, A.M., Kamatou, G.P. 2021. A review of biological activities and phytochemistry of six ethnomedicinally important South African Croton Journal of Ethnopharmacology 280: 114416. Doi: https://doi.org/10.1016/j.jep.2021.114416
- Chipiti, T., Viljoen, A.M., Cordero-Maldonado, M.L., Veale, C.G.L., van Heerden, F.R., Sandasi, M., Chen, W., Crawford, A.D., Enslin, G.M. Anti-seizure activity of African medicinal plants: The identification of bioactive alkaloids from the stem bark of Rauvolfia caffra using an in vivo zebrafish model. Journal of Ethnopharmacology 279: 114282. Doi: https://doi.org/10.1016/j.jep.2021.114282
- Rapper, S.L.-D., Tankeu, S.Y., Kamatou, G., Viljoen, A., van Vuuren, S. 2021. The use of chemometric modelling to determine chemical composition-antimicrobial activity relationships of essential oils used in respiratory tract infections. Fitoterapia 154:105024. Doi: https://doi.org/10.1016/j.fitote.2021.105024
- Semwal, R.B., Semwal, D.K., Combrinck, S., Viljoen, A. 2021. Emodin – a natural anthraquinone derivative with diverse pharmacological activities. Phytochemistry 190: 112854. Doi: https://doi.org/10.1016/j.phytochem.2021.112854
- Ahmad, A., Elisha, I.L., Van Vuuren, S., Viljoen, A. 2021. Volatile phenolics: A comprehensive review of the anti-infective properties of an important class of essential oil constituents. Phytochemistry 190: 112864. Doi: https://doi.org/10.1016/j.phytochem.2021.112864
- Augustyn, W., Viljoen, A., Schripsema, J. 2021. Metabolomics of baobab oil—analysis and authentication of cyclopropenoid fatty acids using similarity and differential NMR spectroscopy. Journal of Food Composition and Analysis 102: 104000. Doi: https://doi.org/10.1016/j.jfca.2021.104000
- Lim Ah Tock., M.J., Chen, W., Combrinck, S., Sandasi, M., Kamatou, G.P., Viljoen, A.M. Exploring the phytochemical variation of non-volatile metabolites within three South African Salvia species using UPLC-MS fingerprinting and chemometric analysis. Fitoterapia 152: 104940. Doi: https://doi.org/10.1016/j.fitote.2021.104940
- Moremi, M.P., Kamatou, G.P., Viljoen, A.M., Tankeu, S.Y. 2021. Croton gratissimus – essential oil composition and chemometric analysis of an ethnomedicinally important tree from South Africa. South African Journal of Botany 138: 141–147. Doi: https://doi.org/10.1016/j.sajb.2020.12.015
- Anokwuru, C.P., Sandasi, M., Chen, W., Van Vuuren, S., Elisha, I.L., Combrinck, S., Viljoen, A.M. 2021. Investigating antimicrobial compounds in South African Combretaceae species using a biochemometric approach. Journal of Ethnopharmacology 269: 113681. Doi: https://doi.org/10.1016/j.jep.2020.113681
- Elisha, I.L., Viljoen, A. Trends in rooibos tea (Aspalathus linearis) research (1994–2018): A scientometric assessment. South African Journal of Botany 137: 159–170. Doi: https://doi.org/10.1016/j.sajb.2020.10.004
- Serabele, K., Chen, W., Tankeu, S., Combrinck, S., Veale, C.G.L., Van Vuuren, S., Chaudhary, S.K., Viljoen, A. 2021. Comparative chemical profiling and antimicrobial activity of two interchangeably used ‘Imphepho’ species (Helichrysum odoratissimum and Helichrysum petiolare). South African Journal of Botany 137: 117–132. Doi: https://doi.org/10.1016/j.sajb.2020.09.023
- Mikayoulou, M., Mayr, F., Temml, V., Pandian, A., Vermaak, I., Chen, W., Komane, B., Stuppner, H., Viljoen, A. 2021. Anti-tyrosinase activity of South African Aloe species and isolated compounds plicataloside and aloesin. Fitoterapia 150: 104828. Doi: https://doi.org/10.1016/j.fitote.2021.104828
- Mulaudzi, N., Anokwuru, C.P., Tankeu, S.Y., Combrinck, S., Chen, W., Vermaak, I., Viljoen, A.M. 2021. Phytochemical profiling and quality control of Terminalia sericea ex DC. using HPTLC metabolomics. Molecules 26(2): 432. Doi: https://doi.org/10.3390/molecules26020432
- Chaudhary, S.K., Sandasi, M., Makolo, F., Van Heerden, F.R., Viljoen, A.M. 2021. Aspalathin: a rare dietary dihydrochalcone from Aspalathus linearis (rooibos tea). Phytochemistry Reviews 20: 1161–1192. Doi: https://doi.org/10.1007/s11101-021-09741-9
- Maphanga, V.B., Skalicka-Woźniak, K., Budzynska, B., Enslin, G.M., Viljoen, A.M. 2020. Screening selected medicinal plants for potential anxiolytic activity using an in vivo zebrafish model. Psychopharmacology 237(12): 3641–3652. Doi: https://doi.org/10.1007/s00213-020-05642-5
- Leonard, C., Kamatou, G., Van Vuuren, S., Sandasi, M., Viljoen, A. 2020. Essential oil variation within Warburgia salutaris–a coveted ethnomedicinal aromatic tree. Chemistry and Biodiversity 17(11): e2000542. Doi: https://doi.org/10.1002/cbdv.202000542
- Sotenjwa, V.Z., Chen, W., Veale, C.G.L., Anokwuru, C.P., Tankeu, S.Y., Combrinck, S., Kamatou, G.P.P., Viljoen, A.M. 2020. Chemotypic variation of non-volatile constituents of Artemisia afra (African wormwood) from South Africa. Fitoterapia 147: 104740. Doi: https://doi.org/10.1016/j.fitote.2020.104740
- Anokwuru, C.P., Tankeu, S., Van Vuuren, S., Viljoen, A., Ramaite, I.D.I., Taglialatela-Scafati, O., Combrinck, S. 2020. Unravelling the antibacterial activity of Terminalia sericea root bark through a metabolomic approach. Molecules 25 (16): 3683. Doi: https://doi.org/10.3390/molecules25163683
- Zwane, B.N., Kamatou, G.P., Viljoen, A.M., Betti, G., Schmidt, M. 2020. Variation in headspace volatiles of Saffron determined by GC×GC-ToF-MS. Natural Product Communications 15 (11): 1–9. Doi: https://doi.org/10.1177/1934578X20967612
- Sibanyoni, M.N., Chaudhary, S.K., Chen, W., Adhami, H.-R., Combrinck, S., Maharaj, V., Schuster, D., Viljoen, A. 2020. Isolation, in vitro evaluation and molecular docking of acetylcholinesterase inhibitors from South African Amaryllidaceae. Fitoterapia 146: 104650. Doi: https://doi.org/10.1016/j.fitote.2020.104650
- Lim Ah Tock, M.J., Kamatou, G.P.P., Combrinck, S., Sandasi, M., Viljoen, A.M. 2020. A chemometric assessment of essential oil variation of three Salvia species indigenous to South Africa. Phytochemistry 172: 112249. Doi: https://doi.org/10.1016/j.phytochem.2019.112249
- Zulfiqar, F., Khan, S.I., Ali, Z., Wang, Y.-H., Ross, S.A., Viljoen, A.M., Khan, I.A. 2020. Norlignan glucosides from Hypoxis hemerocallidea and their potential in vitro anti-inflammatory activity via inhibition of iNOS and NF-κB. Phytochemistry 172: 112273. Doi: https://doi.org/10.1016/j.phytochem.2020.112273
- Segone, R.T., Tankeu, S.Y., Chen, W., Combrinck, S., Schmidt, M., Viljoen, A. 2020. Rapid differentiation of Piper methysticum (kava) plant parts using single point and imaging vibrational spectroscopy. Journal of Applied Research on Medicinal and Aromatic Plants 16: 100235. Doi: https://doi.org/10.1016/j.jarmap.2019.100235
- Heinrich M., Appendino G., Efferth T., Fürst R., Izzo A.A., Kayser O., Pezzuto J.M., Viljoen A. Best practice in research – overcoming common challenges in phytopharmacological research. Journal of Ethnopharmacology 246: 112230. Doi: https://doi.org/10.1016/j.jep.2019.112230
- Semwal, R.B., Semwal, D.K., Combrinck, S., Viljoen, A. 2020. Health benefits of chromones: common ingredients of our daily diet. Phytochemistry Reviews 19 (4): 761–785. Doi: https://doi.org/10.1007/s11101-020-09681-w
2010 - 2019
- Van Vuuren S., Orchard A., Viljoen A. 2019. Essential oils: Fragrant pools of antimicrobial synergism explored. Synergy 9: 100051. Doi: https://doi.org/10.1016/j.synres.2019.100051
- De Rapper S., van Vuuren S., Viljoen A. 2019. Making connections: Linking redolent synergy to the aroma therapeutic treatment of respiratory tract infections. Synergy 9: 100050. Doi: https://doi.org/10.1016/j.synres.2019.100050
- Bae, J.-Y., Ali, Z., Wang, Y.-H., Chittiboyina, A.G., Zaki, A.A., Viljoen, A.M., Khan, I.A. 2019. Anthraquinone-based specialized metabolites from rhizomes of Bulbine natalensis. Journal of Natural Products 82: 1893–1901. Doi: https://doi.org/10.1021/acs.jnatprod.9b00187
- Van Vuuren, S., Ramburrun, S., Kamatou, G., Viljoen, A. 2019. Indigenous South African essential oils as potential antimicrobials to treat foot odour (bromodosis). South African Journal of Botany 126: 354–361. Doi: https://doi.org/10.1016/j.sajb.2019.06.019
- Makolo, F., Viljoen, A., Veale, C.G.L. 2019. Mesembrine: The archetypal psycho-active Sceletium Phytochemistry 166: 112061. Doi: https://doi.org/10.1016/j.phytochem.2019.112061
- Semwal, R.B., Semwal, D.K., Combrinck, S., Trill, J., Gibbons, S., Viljoen, A. 2019. Acacetin—A simple flavone exhibiting diverse pharmacological activities. Phytochemistry Letters 32: 56–65. Doi: https://doi.org/10.1016/j.phytol.2019.04.021
- Calitz, C., Hamman, J.H., Fey, S.J., Viljoen, A.M., Gouws, C., Wrzesinski, K. 2019. A sub-chronic Xysmalobium undulatum hepatotoxicity investigation in HepG2/C3A spheroid cultures compared to an in vivo Journal of Ethnopharmacology 239: 111897. Doi: https://doi.org/10.1016/j.jep.2019.111897
- Kharsany, A. Viljoen, C. Leonard, S. van Vuuren. 2019. The new buzz: Investigating the antimicrobial interactions between bioactive compounds found in South African propolis. Journal of Ethnopharmacology 238: 111867. Doi: https://doi.org/10.1016/j.jep.2019.111867
- Yin, H., Ali, Z., Ding, Y., Wang, Y.-H., Cunningham, M.J., Ibrahim, M.A., Chittiboyina, A.G., Wang, W., Viljoen, A.M., Khan, I.A. 2019. Sceletorines A and B, two minor novel dimeric alkaloids of Mesembryanthemum tortuosum (synonym Sceletium tortuosum). Phytochemistry Letters 31: 78–84. Doi: https://doi.org/10.1016/j.phytol.2019.03.013
- Chen, W., Viljoen, A.M. 2019. To ferment or not to ferment Sceletium tortuosum – Do our ancestors hold the answer? South African Journal of Botany 122: 543–546. Doi: https://doi.org/10.1016/j.sajb.2018.10.011
- Viljoen, A., Sandasi, M., Vermaak, I. 2019. The role of the South African Journal of Botany as a vehicle to promote medicinal plant research– a bibliometric appraisal. South African Journal of Botany 122: 3–10. Doi: https://doi.org/10.1016/j.sajb.2018.07.024
- Baloyi, IT., Cosa, S., Combrinck, S., Leonard, C.M., Viljoen, A.M. 2019. Anti-quorum sensing and antimicrobial activities of South African medicinal plants against uropathogens. South African Journal of Botany 122: 484–491. Doi: https://doi.org/10.1016/j.sajb.2019.01.010
- Aboobaker, Z., Viljoen, A., Chen, W., Crous, P.W., Maharaj, V.J., van Vuuren, S. Endophytic fungi isolated from Pelargonium sidoides DC: antimicrobial interaction and isolation of a bioactive compound. South African Journal of Botany 122: 535–542. Doi: https://doi.org/10.1016/j.sajb.2019.01.011
- Fantoukh, O.I., Dale, O.R., Parveen, A., Hawwal, M.F., Ali, Z., Manda, V.K., Khan, S.I., Chittiboyina, A.G., Viljoen, A., Khan, I.A. 2019. Safety assessment of phytochemicals derived from the globalized South African rooibos tea (Aspalathus linearis) through Interaction with CYP, PXR, and P-gp. Journal of Agricultural and Food Chemistry 67 (17): 4967–4975. Doi: https://doi.org/10.1021/acs.jafc.9b00846
- Cosa, S., Chaudhary, S.K., Chen, W., Combrinck, S., Viljoen, A. 2019. Exploring common culinary herbs and spices as potential anti-quorum sensing agents. Nutrients 11 (4), 739. Doi: https://doi.org/10.3390/nu11040739
- Orchard, A., van Vuuren, S.F., Viljoen, A.M. 2019. Commercial essential oil combinations against topical fungal pathogens. Natural Product Communications 14: 151–158. Doi:
https://doi.org/10.1177/1934578X1901400139
- Rubegeta, E., Ahmad, A., Kamatou, G.P.P., Sandasi, M., Sommerlatte, H., Viljoen, A.M. 2019. Headspace analysis, antimicrobial and anti-quorum sensing activities of seven selected African Commiphora South African Journal of Botany 122: 522–528. Doi: https://doi.org/10.1016/j.sajb.2018.03.001
- Orchard, A., Kamatou, G., Viljoen, A.M., Patel, N., Mawela, P., van Vuuren, S.F. The influence of carrier oils on the antimicrobial activity and cytotoxicity of essential oils. Evidence Based Complementary and Alternative Medicine 6981305: 1–24. Doi: https://doi.org/10.1155/2019/6981305
- Kamatou, G., Sandasi, M., Tankeu, S., Vuuren, S.V., Viljoen, A. 2019. Headspace analysis and characterisation of South African propolis volatile compounds using GCxGC–ToF–MS. Brazilian Journal of Pharmacognosy 29: 351-357. Doi: https://doi.org/10.1016/j.bjp.2018.12.002
- Orchard A., Viljoen A., van Vuuren S. Wound pathogens: investigating antimicrobial activity of commercial essential oil combinations against reference strains. Chemistry and Biodiversity 15: e1800405. Doi: https://doi.org/10.1002/cbdv.201800405
- Calitz, C., Hamman, J.H., Viljoen, A.M., Fey, S.J., Wrzesinski, K., Gouws, C. 2018. Toxicity and anti-prolific properties of Xysmalobium undulatum water extract during short-term exposure to two-dimensional and three-dimensional spheroid cell cultures. Toxicology Mechanisms and Methods 28: 641–652. Doi: https://doi.org/10.1080/15376516.2018.1485805
- Mokhetho, K.C., Sandasi, M., Ahmad, A., Kamatou, G.P., Viljoen, A.M. 2018. Identification of potential anti-quorum sensing compounds in essential oils: a gas chromatography-based metabolomics approach. Journal of Essential Oil Research, 30: 399–408. Doi: https://doi.org/10.1080/10412905.2018.1503100
- Orchard, A., van Vuuren, S.F., Viljoen, A.M., Kamatou, G. 2018. The in vitro antimicrobial evaluation of commercial essential oils and their combinations against acne. International Journal of Cosmetic Science 40: 226–243. Doi: https://doi.org/10.1111/ics.12456
- Zhao, J., Khan, I.A., Combrinck, S., Sandasi, M., Chen, W., Viljoen, A.M. 2018. 1H-NMR and UPLC-MS metabolomics: Functional tools for exploring chemotypic variation in Sceletium tortuosum from two provinces in South Africa. Phytochemistry 152: 191–203. Doi: https://doi.org/10.1016/j.phytochem.2018.03.013
- Mavimbela, T., Vermaak, I., Chen, W., Viljoen, A.M. Rapid quality control of Sutherlandia frutescens leaf material through the quantification of SU1 using vibrational spectroscopy in conjunction with chemometric data analysis. Phytochemistry Letters 25: 184–190. Doi: https://doi.org/10.1016/j.phytol.2018.03.003
- Havenga, K., Abay, E., Wiesner, L., Viljoen, A.M., Steyn, D., Hamman, J. 2018. The in vitro and in vivo effects of Hypoxis hemerocallidea on indinavir pharmacokinetics: modulation of efflux. Planta Medica 84: 895–901. Doi: https://doi.org/10.1055/a-0607-2743
- Lerotholi, L.J., Chaudhary, S.K., Chen, W., Veale, C.G.L., Combrinck, S., Viljoen, A.M. Identification, isolation and determination of biomarkers for quality control of Bush tea (Athrixia phyllicoides) Planta Medica 84: 902–912. Doi: https://doi.org/10.1055/a-0594-9527
- Sandasi, M., Chen, W., Vermaak, I., Viljoen, A.M. 2018. Non-destructive quality assessment of herbal tea blends using hyperspectral imaging. Phytochemistry Letters 24: 94–101. Doi: https://doi.org/10.1016/j.phytol.2018.01.016
- Tankeu, S., Vermaak, I., Chen, W., Sandasi, M., Kamatou, G., Viljoen, A.M. Hyperspectral imaging and support vector machine: A powerful combination to differentiate Black Cohosh (Actaea racemosa) from other Cohosh species. Planta Medica 84: 407–419. Doi: https://doi.org/10.1055/s-0043-119887
- Orchard, A., Viljoen, A.M, van Vuuren, S. 2018. Antimicrobial essential oil combinations to combat foot odour. Planta Medica 84: 662–673. Doi: https://doi.org/10.1055/a-0592-8022
- Mmopele, K., Combrinck, S., Hamman, J., Willers, C., Chen, W., Viljoen, A. Potential herb-drug pharmacokinetic interactions between African wild olive leaf extract and selected antihypertensive drugs. Planta Medica 84: 886–894. Doi: https://doi.org/10.1055/a-0583-0543
- Veale, C.G.L., Chen, W., Chaudhary, S., Kituyi, S.N., Isaacs, M., Hoppe, H., Edkins, A.L., Combrinck, S., Mehari, B., Viljoen, A.M. NMR structural elucidation of channaine, an unusual alkaloid from Sceletium tortuosum. Phytochemistry Letters 23: 189–193. Doi: https://doi.org/10.1016/j.phytol.2017.11.018
- Pudumo, J., Chaudhary, S.K., Chen, W., Viljoen, A.M., Vermaak, I., Veale, C.G.L. 2018. HPTLC fingerprinting of Croton gratissimus leaf extract with preparative HPLC-MS-isolated marker compounds. South African Journal of Botany 114: 32–36. Doi: https://doi.org/10.1016/j.sajb.2017.10.004
- Waltenberger, B., Halabalaki, M., Schwaiger, S., Adamopoulos, N., Allouche, N., Fiebich, B.L., Hermans, N., Jansen-D rr, P., Kesternich, V., Pieters, L., Schnbichler, S., Skaltsounis, A.-L., Tran, H., Trougakos, I.P., Viljoen, A.M., Wolfender, J.-L., Wolfrum, C., Xynos, N., Stuppner, H. 2018. Novel natural products for healthy ageing from the Mediterranean diet and food plants of other global sources—The Medihealth project. Molecules 23: 1097. Doi: https://doi.org/10.3390/molecules23051097
- Kamatou, G.P.P., Viljoen, A.M. Comparison of fatty acid methyl esters of Palm and Palmist oils determined by GCxGC–ToF–MS and GC–MS/FID. South African Journal of Botany 112: 483–488. Doi: https://doi.org/10.1016/j.sajb.2017.06.032
- Komane, B., Vermaak, I., Kamatou, G., Summers, B., Viljoen, A.M. The topical efficacy and safety of Citrullus lanatus seed oil: A short-term clinical assessment. South African Journal of Botany 112: 466–473. Doi: https://doi.org/10.1016/j.sajb.2017.06.028
- Sobiyi, O.K., Kamatou, G.P.P., Viljoen, A.M., Magee, A.R., Van Wyk, B.-E. 2017. Volatile constituents of Notobubon and Nanobubon (Apiaceae, tribe Tordylieae). Journal of Essential Oil Research 29: 289–298. Doi: https://doi.org/10.1080/10412905.2016.1259664
- Lerotholi, L., Chaudhary, S.K., Combrinck, S., Viljoen, A. Bush tea (Athrixia phylicoides): A review of the traditional uses, bioactivity and phytochemistry. South African Journal of Botany 110: 4–17. Doi: https://doi.org/10.1016/j.sajb.2016.06.005
- Nsuala, B.N., Kamatou, G.P., Sandasi, M., Enslin, G., Viljoen, A.M. Variation in essential oil composition of Leonotis leonurus, an important medicinal plant in South Africa. Biochemical Systematics and Ecology 70: 155–161. Doi: https://doi.org/10.1016/j.bse.2016.11.009
- Djokam, M., Sandasi, M., Chen, W., Viljoen, A., Vermaak, I. 2017. Hyperspectral imaging as a rapid quality control method for herbal tea blends. Applied Sciences 7: 268. Doi: https://doi.org/10.3390/app7030268
- Orchard, A., Sandasi, M., Kamatou, G., Viljoen, A.M, van Vuuren, S. 2017. The in vitro antimicrobial activity and chemometric modelling of 59 commercial essential oils against pathogens of dermatological relevance. Chemistry and Biodiveristy 14:1–18. Doi: https://doi.org/10.1002/cbdv.201600218
- Komane, B., Vermaak, I., Kamatou, G.P.P., Summers, B., Viljoen, A.M. 2017. Beauty in Baobab: A pilot study of the safety and efficacy of Adansonia digitata seed oil. Brazilian Journal of Pharmacognosy 27: 1–8. Doi: https://doi.org/10.1016/j.bjp.2016.07.001
- De Rapper, S., Viljoen, A.M., Van Vuuren, S.F. 2016. The in vitro antimicrobial effects of Lavandula angustifolia essential oil in combination with conventional antimicrobial agents. Evidence-Based Complementary and Alternative Medicine 2016: 2752739. Doi: https://doi.org/10.1155/2016/2752739
- Kanama, S., Viljoen, A.M., Enslin, G., Kamatou, G.P.P., Chen, W., Sandasi, M., Idowu, T. 2016. Uzara – a quality control perspective of Xysmalobium undulatum. Pharmaceutical Biology 54: 1272–1279. Doi: https://doi.org/10.3109/13880209.2015.1073335
- Chen, W., Nkosi, T.A.N., Combrinck, S., Viljoen, A.M., Cartwright-Jones, C. 2016. Rapid analysis of the skin irritant p-phenylenediamine (PPD) in henna products using atmospheric solids analysis probe mass spectrometry. Journal of Pharmaceutical and Biomedical Analysis 128: 119–125. Doi: https://doi.org/10.1016/j.jpba.2016.05.020
- Hulley, I.M., Tilney, P.M., Van Vuuren, S.F., Kamatou, G.P.P., Viljoen A.M., Van Wyk, B-E. 2016. San and Nama indigenous knowledge: the case of lnhora (Pteronia camphorata) and its medicinal use. South African Journal of Science 112(9/10): 1–9. Doi: https://doi.org/10.17159/sajs.2016/20160044
- Mahumane, G.D., Van Vuuren, S.F., Kamatou, G.P.P., Sandasi, M., Viljoen, A.M. 2016. Chemical composition and antimicrobial activity of Eucalyptus radiata leaf essential oil, sampled over a year. Journal of Essential Oil Research 28: 475–488. Doi: https://doi.org/10.1080/10412905.2016.1175386
- Sandasi, M., Vermaak, I., Chen, W., Viljoen, A.M. 2016. The application of vibrational spectroscopy techniques in the qualitative assessment of material traded as Ginseng. Molecules 21: 472. Doi: https://doi.org/10.3390/molecules21040472
- Atlabachew M., Combrinck S., Viljoen A.M., Hamman J.H., Gouws C. 2016. Isolation and in vitro permeation of phenylpropylamino alkaloids from Khat (Catha edulis) across oral and intestinal mucosal tissues. Journal of Ethnopharmacology 194: 307–315. Doi: https://doi.org/10.1016/j.jep.2016.09.012
- Semwal D.K., Semwal R.B., Combrinck S., Viljoen A. 2016. Myricetin: A dietary molecule with diverse biological activities. Nutrients 8(2):90. Doi: https://doi.org/10.3390/nu8020090
- Ruiters, A.K., Tilney, P.M., Van Vuuren, S.F., Viljoen, A.M., Kamatou, G.P.P., Van Wyk, B-E. 2016. The anatomy, ethnobotany, antimicrobial activity and essential oil composition of southern African species of Teucrium (Lamiaceae). South African Journal of Botany 102:175-185. Doi: https://doi.org/10.1016/j.sajb.2015.06.008
- Tankeu, S., Vermaak, I., Chen, W., Sandasi, M., Viljoen, A.M. 2015. Application of hyperspectral imaging for the differentiation between two “fang ji” herbal medicines: Stephania tetrandra and the nephrotoxic Aristolochia fangchi. Phytochemistry 122: 213–222. [selected for front cover of journal issue]. Doi: https://doi.org/10.1016/j.phytochem.2015.11.008
- Semwal, R.B., Semwal, D.K., Combrinck, S., Viljoen, A.M. Butein: From ancient traditional remedy to modern nutraceutical. Phytochemistry Letters 11: 188–201. Doi: https://doi.org/10.1016/j.phytol.2014.12.014
- Komane, B., Vermaak, I., Summers, B., Viljoen, A.M. Safety and efficacy of Sclerocarya birrea (A.Rich.) Hochst (Marula) oil: A clinical perspective. Journal of Ethnopharmacology 176: 327–335. Doi: https://doi.org/10.1016/j.jep.2015.10.037
- Atlabachew, M., Combrinck, S., Sandasi, M., Chen, W., Viljoen, A.M. Rapid differentiation of Khat (Catha edulis Vahl. Endl.) using single point and imaging vibrational spectroscopy. Journal of Vibrational Spectroscopy 81: 96–105. Doi: https://doi.org/10.1016/j.vibspec.2015.10.005
- Nsuala, B., Enslin, G., Viljoen, A.M. “Wild cannabis”: a review of the traditional use and phytochemistry of Leonotis leonurus. Journal of Ethnopharmacology 174: 520–539. Doi: https://doi.org/10.1016/j.jep.2015.08.013
- Semwal, R., Semwal, D., Combrinck, S., Viljoen, A.M. 2015. Gingerols and shogaols: Important nutraceutical principles from ginger. Phytochemistry 117: 554–568. [selected for front cover of journal issue] Doi: https://doi.org/10.1016/j.phytochem.2015.07.012
- Suleman, T., Van Vuuren, S.F., Sandasi, M., Viljoen, A.M. 2015. Antimicrobial activity and chemometric modelling of South African propolis. Applied Microbiology 119: 981–990. Doi: https://doi.org/10.1111/jam.12906
- Raman, V., Sagi, S., Gala, A.M., Avula, B., Viljoen, A.M., Khan, I.A. 2015. Adulteration in commercial buchu dietary supplements: analyses of commercial and authentic buchu samples and comparative studies of Agathosma betulina and Agathosma crenulata by microscopy and HPTLC. South African Journal of Botany 100: 122–131. Doi: https://doi.org/10.1016/j.sajb.2015.05.012
- Ahmad, A., Viljoen, A.M. 2015. The in vitro antimicrobial activity of Cymbopogon essential oil (Lemon Grass) and its interaction with silver ions. Phytomedicine 22: 657–665. Doi: https://doi.org/10.1016/j.phymed.2015.04.002
- Semwal, B.R., Semwal, D.K., Vermaak, I., Viljoen, A.M. 2015. A comprehensive scientific overview of Garcinia cambogia. Fitoterapia 102: 134–148. Doi: https://doi.org/10.1016/j.fitote.2015.02.012
- Leonard, C.M., Viljoen, A.M. 2015. Warburgia: A comprehensive review of the botany, traditional uses and phytochemistry. Journal of Ethnopharmacology 165: 260–285. Doi: https://doi.org/10.1016/j.jep.2015.02.021
- Adhami, H.-R., Viljoen, A.M. 2015. Preparative isolation of bio-markers from the leaf exudate of Aloe ferox (“aloe bitters”) by high performance counter-current chromatography. Phytochemistry Letters 11: 321–325. Doi: https://doi.org/10.1016/j.phytol.2014.07.001
- Kasote D., Ahmad A., Viljoen A. 2015. Proangiogenic potential of medicinal plants in wound healing. Evidence-Based Validation of Herbal Medicine Chapter 6 149–164. Doi: https://doi.org/10.1016/B978-0-12-800874-4.00006-4
- Ahmad A., Viljoen A.M., Chenia H.Y. 2015. The impact of plant volatiles on bacterial quorum sensing. Letters in Applied Microbiology 60(1): 8–19. Doi: https://doi.org/10.1111/lam.12343
- Viljoen A.M., Zhao J., Sandasi M., Chen W., Khan I.A. 2015. Phytochemical distinction between Pelargonium sidoides (“Umckaloabo”) and P. reniforme through 1H-NMR and UHPLC–MS metabolomic profiling. Metabolomics 11:594–602. Doi: https://doi.org/10.1007/s11306-014-0722-2
- Kanama S.K., Viljoen A.M., Kamatou G.P.P., Chen W., Sandasi M., Adhami H.-R., Van Wyk B.-E. 2015. Simultaneous quantification of anthrones and chromones in Aloe ferox (“Cape aloes”) using UHPLC-MS. Phytochemistry Letters 13: 85–90. Doi: https://doi.org/10.1016/j.phytol.2015.04.025
- Skalicka-Woźniak K., Viljoen A.M. 2015. Guest Editorial: International Symposium on Chromatography of Natural Products (ISCNP). Phytochemistry Letters 11: 320. Doi: https://doi.org/10.1016/j.phytol.2015.01.013
- Kasote D., Ahmad A., Chen W., Combrinck S., Viljoen A. 2015. HPTLC-MS as an efficient hyphenated technique for the rapid identification of antimicrobial compounds from propolis. Phytochemistry 11: 326–331. Doi: https://doi.org/10.1016/j.phytol.2014.08.017
- Bassey, K., Viljoen, A.M., Combrinck, S., Choi, Y.H. 2014. New phytochemicals from the corms of medicinally important South African Hypoxis species. Phytochemistry Letters 10: lxix–lxxv. Doi: https://doi.org/10.1016/j.phytol.2014.09.014
- Maree, J.E., Khondkar, P., Kwapong, A., Oyedemi, B.M., Aljarba, T.M., Stapleton, P., Viljoen, A.M., Gibbon, S. 2014. Bioactive acetophenones from Plectranthus venteri. Phytochemistry Letters 10: cxli–cxliv. Doi: https://doi.org/10.1016/j.phytol.2014.10.021
- Sandasi, M., Vermaak, I., Chen, W., Viljoen, A.M. 2014. Hyperspectral imaging and chemometric modeling of Echinacea – a novel approach in the quality control for herbal medicines. Molecules 19: 13104–13121. Doi: https://doi.org/10.3390/molecules190913104
- Vermaak, I., Enslin, G., Idowu, T., Viljoen, A.M. 2014. Xysmalobium undulatum (Uzara) – review of an antidiarrhoeal traditional medicine. Journal of Ethnopharmacology 156: 135–146. Doi: https://doi.org/10.1016/j.jep.2014.08.016
- Sandasi, M., Vermaak, I., Chen, W., Viljoen, A.M. 2014. Skullcap and germander: Preventing potential toxicity through the application of hyperspectral imaging and multivariate image analysis as a novel quality control method. Planta Medica 80: 1329–1339. Doi: https://doi.org/10.1055/s-0034-1383037
- Semwal, D., Semwal, R., Vermaak, I., Viljoen, A.M. 2014. From arrow poison to herbal medicine – the ethnobotanical, phytochemical and pharmacological significance of Cissampelos (Menispermaceae). Journal of Ethnopharmacology 155: 1011–1028. Doi: https://doi.org/10.1016/j.jep.2014.06.054
- Mncwangi, N.P., Viljoen, A.M., Zhao, J., Vermaak, I., Chen, W., Khan, I. 2014. What the devil is in your phytomedicine? Exploring species substitution in Harpagophytum through chemometric modeling of 1H-NMR and UHPLC-MS datasets. Phytochemistry 106: 104–115. Doi: https://doi.org/10.1016/j.phytochem.2014.06.012
- Debabrata, A., Enslin, G., Chen, W., Sandasi, M., Mavimbela, T., Viljoen, A.M. 2014. A chemometric approach to the quality control of Sutherlandia (Cancer Bush). Biochemical Systematics and Ecology 56: 221–230. Doi: https://doi.org/10.1016/j.bse.2014.06.009
- Semwal, R., Semwal, D., Combrinck, S., Cartwright-Jones, C., Viljoen, A.M. 2014. Lawsonia inermis L. (henna): Ethnobotanical, phytochemical and pharmacological aspects. Journal of Ethnopharmacology 155: 80–103. Doi: https://doi.org/10.1016/j.jep.2014.05.042
- Tankeu, S., Vermaak, I., Kamatou, G.P.P., Viljoen, A.M. 2014. Vibrational spectroscopy and chemometric modelling: An economical and robust quality control method for lavender oil. Industrial Crops and Products 59: 234–240. Doi: https://doi.org/10.1016/j.indcrop.2014.05.005
- Mavimbela, T., Vermaak, I., Viljoen, A.M. 2014. Differentiating between Agathosma betulina and Agathosma crenulata – a quality control perspective. Journal of Applied Research on Medicinal and Aromatic Plants 1: e8–e14. (New Journal) Doi: https://doi.org/10.1016/j.jarmap.2014.04.002
- Kasote, D., Suleman, T., Chen, W., Sandasi, M., Viljoen, A.M., Van Vuuren, S.F. 2014. Chemical profiling and chemometric analysis of South African propolis. Biochemical Systematics and Ecology 55: 156–163. Doi: https://doi.org/10.1016/j.bse.2014.03.012
- Ahmad, A., Van Vuuren, S.F., Viljoen, A.M. 2014. Unravelling the complex antimicrobial interactions of essential oils – the case of Thymus vulgaris (Thyme). Molecules 19: 2896–2910. Doi: https://doi.org/10.3390/molecules19032896
- Tankeu, S., Vermaak, I., Kamatou, G.P.P., Viljoen, A.M. 2014. Vibrational spectroscopy as a rapid quality control method for Melaleuca alternifolia Cheel (Tea Tree Oil). Phytochemical Analysis 25: 81–88. Doi: https://doi.org/10.1002/pca.2470
- Mncwangi, N.P., Vermaak, I., Viljoen, A.M. 2014. Mid-infrared spectroscopy and short wave infrared hyperspectral imaging – a novel approach in the qualitative assessment of Harpagophytum procumbens and H. zeyheri (Devil’s Claw). Phytochemistry Letters 7: 143–149. Doi: https://doi.org/10.1016/j.phytol.2013.11.007
- Maree, J., Kamatou, G.P.P., Gibbons, S., Viljoen, A.M., van Vuuren, S.F. 2014. The application of GC-MS combined with chemometrics for the identification of antimicrobial compounds from selected commercial essential oils. Chemometrics and Intelligent Laboratory Systems 130: 172–181. Doi: https://doi.org/10.1016/j.chemolab.2013.11.004
- Van Vuuren, S.F., Docrat, Y., Kamatou, G.P.P., Viljoen, A.M. 2014. Essential oil composition and antimicrobial interactions of understudied tea tree species. South African Journal of Botany 92: 7–14. Doi: https://doi.org/10.1016/j.sajb.2014.01.005
- Tankeu, S., Vermaak, I., Viljoen, A.M., Sandasi, M., Kamatou, G.P.P. 2013. Essential oil variation of Tagetes minuta in South Africa – a chemometric approach. Biochemical Systematics and Ecology 51: 320–327. Doi: https://doi.org/10.1016/j.bse.2013.10.003
- Sandasi, M., Kamatou, G.P.P., Combrinck, S., Viljoen, A.M. 2013. A chemotaxonomic assessment of four indigenous South African Lippia species using GC–MS and vibrational spectroscopy of the essential oils. Biochemical Systematics and Ecology 51: 142–152. Doi: https://doi.org/10.1016/j.bse.2013.08.028
- Kamatou, G.P.P., Vermaak, I., Viljoen, A.M., Lawrence, B. 2013. Menthol: A simple monoterpene with remarkable biological properties. Phytochemistry 96: 15–25. Doi: https://doi.org/10.1016/j.phytochem.2013.08.005
- Chen, W., Vermaak, I., Viljoen, A.M. 2013. Camphor – A fumigant during the black death and a coveted fragrant wood in ancient Egypt and Babylon – a review. Molecules 18: 5434–5454. Doi: https://doi.org/10.3390/molecules18055434
- De Rapper, S., Van Vuuren, S.F., Kamatou, G.P.P., Viljoen, A.M. 2013. The in vitro antimicrobial activity of Lavandula angustifolia essential oil in combination with other aroma-therapeutic oils. Evidence-Based Complementary and Alternative Medicine 2013: 852049. Doi: https://doi.org/10.1155/2013/852049
- Mabona, U., Viljoen, A.M., Shikanga, E., Marston, A., Van Vuuren, S.F. 2013. Antimicrobial activity of southern African medicinal plants with dermatological relevance: From an ethnopharmacological screening approach, to combination studies and the isolation of a bioactive compound. Journal of Ethnopharmacology 148: 45–55. Doi: https://doi.org/10.1016/j.jep.2013.03.056
- Shikanga, E., Viljoen, A.M., Vermaak, I., Combrinck, S. 2013. A novel approach in herbal quality control using hyperspectral imaging: Discriminating between Sceletium tortuosum and Sceletium crassicaule. Phytochemical Analysis 24: 550–555. Doi: https://doi.org/10.1002/pca.2431
- Vermaak, I., Viljoen, A.M., Wiklund-Lindström, S. 2013. Hyperspectral imaging in the quality control of herbal medicines – the case of neurotoxic Japanese star anise. Journal of Pharmaceutical and Biomedical Analysis 75: 207–213. Doi: https://doi.org/10.1016/j.jpba.2012.11.039
- Beneke, C., Viljoen, A.M., Hamman, J.H. 2013. Modulation of drug efflux by Aloe materials: an in vitro investigation across rat intestinal tissue. Pharmacognosy Magazine 9: S44–S48. Doi: https://doi.org/10.4103/0973-1296.117864
- Sandasi, M., Kamatou, G.P.P.,Viljoen, A.M. 2012. An untargeted metabolomic approach in the chemotaxonomic assessment of two Salvia species as a potential source of α-bisabolol. Phytochemistry 84: 94–101. Doi: https://doi.org/10.1016/j.phytochem.2012.08.009
- Mncwangi, N.P., Chen,W., Vermaak, I., Viljoen, A.M., Gericke, N. 2012. Devil’s Claw – a review of the ethnobotany, phytochemistry and biological activity of Harpagophytum procumbens. Journal of Ethnopharmacology 143: 755–771. Doi: https://doi.org/10.1016/j.jep.2012.08.013
- Maree, J.E., Viljoen, A.M. 2012. Phytochemical distinction between Pelargonium sidoides and P. reniforme – a quality control perspective. South African Journal of Botany 82: 83–91. Doi: https://doi.org/10.1016/j.sajb.2012.07.007
- Mncwangi, N.P., Viljoen, A.M. 2012. Quantitative variation of amino acids in Sutherlandia frutescens (Cancer bush) – towards setting parameters for quality control. South African Journal of Botany 82: 46–52. Doi: https://doi.org/10.1016/j.sajb.2012.06.009
- Shikanga, E., Viljoen, A.M., Combrinck, S., Marston, A., Gericke, N. 2012. The chemotypic variation of Sceletium tortuosum alkaloids and commercial product formulations. Biochemical Systematics and Ecology 44: 364–373. Doi: https://doi.org/10.1016/j.bse.2012.06.025
- Kamatou, G.P.P., Vermaak, I., Viljoen, A.M. 2012. Eugenol – From the remote Maluku Islands to the international market place: A review of a remarkable and versatile molecule. Molecules 17: 6953–6981. Doi: https://doi.org/10.3390/molecules17066953
- Shikanga, E., Kamatou, G.P.P., Chen, W., Combrinck, S., Viljoen, A.M. 2012. Validated RP–UPLC and GC–MS methods for the analysis of psychoactive alkaloids in Sceletium tortuosum. South African Journal of Botany 82: 99–107. Doi: https://doi.org/10.1016/j.sajb.2012.05.004
- Kamatou, G.P.P., Chen, W., Viljoen, A.M. 2012. Quantification of rosmarinic acid in Salvia species indigenous to South Africa by HPTLC. Journal of Planar Chromatography 5: 403–408. Doi: https://doi.org/10.1556/jpc.25.2012.5.3
- Beneke, C., Viljoen, A.M., Hamman, J.H. 2012. In vitro drug absorption enhancement effects of Aloe vera and Aloe ferox. Scientiae Pharmaceutica 80: 475–486. Doi: https://doi.org/10.3797/scipharm.1202-10
- Shikanga, E., Vermaak, I., Viljoen, A.M. 2012. An HPTLC-densitometry method for the quantification of pharmacologically active alkaloids in Sceletium tortuosum raw material and products. Journal of Planar Chromatography 4: 283–289. Doi: https://doi.org/10.1556/jpc.25.2012.4.1
- Viljoen, A., Vermaak, I. 2012. Special Issue – Quality control. South African Journal of Botany 82: 1-3. Doi: https://doi.org/10.1016/j.sajb.2012.08.006
- Lebitsa, T., Viljoen, A.M., Lu, Z., Hamman, J.H. 2012. In vitro drug permeation enhancement potential of Aloe whole leaf and gel materials. Current Drug Delivery 9: 297–304. Doi: https://doi.org/10.2174/156720112800389115
- De Rapper, S., Van Vuuren, S.F., Kamatou, G.P.P., Viljoen, A.M., Dagne, E. 2012. The additive and synergistic antimicrobial effects of select frankincense and myrrh oils – a combination from the pharaonic pharmacopoeia. Letters in Applied Microbiology 54: 352–358. Doi: https://doi.org/10.1111/j.1472-765X.2012.03216.x
- Viljoen, A.M., Mncwangi, N., Vermaak, I. 2012. Anti-inflammatory iridoids of botanical origin. Current Medicinal Chemistry 19: 2104–2127. Doi: https://doi.org/10.2174/092986712800229005
- Tarirai, C., Viljoen, A.M., Hamman, J.H. 2012. Effects of dietary fruits, vegetables and a herbal tea on the in vitro transport of cimetidine: Comparing the Caco-2 model with porcine jejunum tissue. Pharmaceutical Biology 50: 254–263. Doi: https://doi.org/10.3109/13880209.2011.598169
- Ojewole, E., Mackraj, I., Akhundov, K., Hamman, J., Viljoen, A.M., Olivier, E., Wesley-Smith, J., Govender, T. 2012. Investigating the effect of Aloe vera gel on the buccal permeability of didanosine. Planta Medica 78: 354–361. Doi: https://doi.org/10.1055/s-0031-1280431
- Shikanga, E.A., Hamman, J.H., Chen, W., Combrinck, S., Gericke, N., Viljoen, A.M. 2012. In vitro permeation of mesembrine-alkaloids from Sceletium tortuosum across porcine buccal, sublingual and intestinal mucosa. Planta Medica 78: 260–268. Doi: https://doi.org/10.1055/s-0031-1280367
- Chen, W., Van Wyk, B-E., Vermaak, I., Viljoen, A.M. 2012. Cape aloes – a review of the phytochemistry, pharmacology and commercialisation of Aloe ferox. Phytochemistry Letters 5: 1–12. Doi: https://doi.org/10.1016/j.phytol.2011.09.001
- Van Vuuren, S.F., Viljoen A.M. 2011. Erratum for: Plant-based antimicrobial studies – methods and approaches to study the interaction between natural products. Planta Medica 77: 1168–1182. Doi: https://doi.org/10.1055/s-0031-1298216
- Kamatou, G.P.P., Vermaak, I., Viljoen, A.M. 2011. An updated review of Adansonia digitata: a commercially important African tree. South African Journal of Botany 77: 908–919. Doi: https://doi.org/10.1016/j.sajb.2011.08.010
- Harvey, A.L., Young, L.C., Viljoen, A.M., Gericke, N.P. 2011. Pharmacological actions of the South African medicinal and functional food plant Sceletium tortuosum and its principal alkaloids. Journal of Ethnopharmacology 137: 1124–1129. Doi: https://doi.org/10.1016/j.jep.2011.07.035
- Sandasi, M., Kamatou, G.P.P., Gavaghan, C., Baranska, M., Viljoen, A.M. 2011. A quality control method for geranium oil based on vibrational spectroscopy and chemometric data analysis. Vibrational Spectroscopy 57: 242–247. Doi: https://doi.org/10.1016/j.vibspec.2011.08.002
- Van Wyk, B.E., Viljoen, A. 2011. Special issue on economic botany. South African Journal of Botany, 77(4): 809–811. Doi: https://doi.org/10.1016/j.sajb.2011.09.008
- Vermaak, I., Kamatou, G.P.P., Komane-Mofokeng, B.M., Viljoen, A.M., Beckett, K. 2011. African seed oils of commercial importance – cosmetic applications. South African Journal of Botany 77: 920–933. Doi: https://doi.org/10.1016/j.sajb.2011.07.003
- Jambwa, T., Viljoen, A.M., Hamman, J.H. 2011. Matrix forming excipients from natural origin for controlled release matrix type tablets. Journal of Drug Delivery Science and Technology 5: 433–439. Doi: https://doi.org/10.1016/S1773-2247(11)50069-3
- Vermaak, I., Viljoen A.M., Hamman, J.H. 2011. Natural products in anti-obesity therapy. Natural Product Reports 28: 1493–1533. Doi: https://doi.org/10.1039/C1NP00035G
- Sandasi, M., Kamatou, G.P.P., Viljoen, A.M. 2011. Chemotaxonomic evidence suggests that Eriocephalus tenuifolius is the source of Cape chamomile oil and not E. punctulatus. Biochemical Systematics and Ecology 39: 328–338. Doi: https://doi.org/10.1016/j.bse.2011.04.003
- Shikanga, E.A., Viljoen, A.M., Combrinck, S., Marston, A. 2011. Isolation of Sceletium alkaloids by high-speed countercurrent chromatography. Phytochemistry Letters 4: 190–193. Doi: https://doi.org/10.1016/j.phytol.2011.03.003
- Vermaak, I., Hamman, J.H., Chen, W., Viljoen A.M. 2011. In vitro transport of the steroidal glycoside P57 from Hoodia gordonii across excised porcine intestinal and buccal tissue. Phytotherapy Research 18: 783–787. Doi: https://doi.org/10.1016/j.phymed.2011.01.017
- Sandasi, M., Leonard, C.M., van Vuuren, S.F., Viljoen, A.M. 2011. Peppermint (Mentha piperita) inhibits microbial biofilms in vitro. South African Journal of Botany 77: 80–85. Doi: https://doi.org/10.1016/j.sajb.2010.05.011
- Lourens, A.C.U., Van Vuuren, S.F., Viljoen, A.M., Davids, H., Van Heerden, F.R. 2011. Antimicrobial activity and in vitro cytotoxicity of selected South African Helichrysum species. South African Journal of Botany 77: 229–235. Doi: https://doi.org/10.1016/j.sajb.2010.05.006
- Hulley, I.M., Viljoen A.M., Tilney, P.M., Van Vuuren, S.F., Kamatou, G.P.P., Van Wyk, B-E. 2011. Pteronia divaricata (Asteraceae): A newly recorded Cape herbal medicine. South African Journal of Botany 77: 66–74. Doi: https://doi.org/10.1016/j.sajb.2010.05.010
- Pather, N., Viljoen, A.M., Kramer, B. 2011. A biochemical comparison of the in vivo effects of Bulbine frutescens and Bulbine natalensis on cutaneous wound healing. Journal of Ethnopharmacology 133: 364–370. Doi: https://doi.org/10.1016/j.jep.2010.10.007
- Jambwa, T., Viljoen, A., Hamman, J. 2011. Aloe gel and whole-leaf raw materials: Promising excipients for the production of matrix-type tablets. SA Pharmaceutical Journal, 78(1): 51–54. Doi: https://hdl.handle.net/10520/EJC82491
- Vermaak, I., Hamman, J.H., Viljoen A.M. 2011. Hoodia gordonii: An up-to-date review of a commercially important anti-obesity plant. Planta Medica 77: 1149–1160. Doi: https://doi.org/10.1055/s-0030-1250643
- Komane, B.M., Olivier, E., Viljoen, A.M. 2011. Trichilia emetica (Meliaceae) – a review of traditional uses, biological activities and phytochemistry. Phytochemistry 4: 1–9. Doi: https://doi.org/10.1016/j.phytol.2010.11.002
- Maree, J.E., Viljoen, A.M. 2011. Fourier transform near- and mid-infrared spectroscopy can distinguish between the commercially important Pelargonium sidoides and its close taxonomic ally P. reniforme. Journal of Vibrational Spectroscopy 55: 146–152. Doi: https://doi.org/10.1016/j.vibspec.2010.10.005
- Tarirai, C., Viljoen, A.M., Hamman, J.H. 2010. Herb-drug pharmacokinetic interactions reviewed. Expert Opinion on Drug Metabolism and Toxicology 6: 1–24. Doi: https://doi.org/10.1517/17425255.2010.529129
- Hulley, I.M., Viljoen A.M., Tilney, P.M., Van Vuuren, S.F., Kamatou, G.P.P., Van Wyk, B-E. 2010. The ethnobotany, leaf anatomy, essential oil variation and biological activity of Pteronia incana (Asteraceae). South African Journal of Botany 76: 668–675. Doi: https://doi.org/10.1016/j.sajb.2010.08.007
- Van Zyl, R.L., Seatholo, S.T., Viljoen, A.M. 2010. Pharmacological interactions of essential oil constituents on the in vitro growth of Plasmodium falciparum. South African Journal of Botany 76: 662–667. Doi: https://doi.org/10.1016/j.sajb.2010.08.002
- Sandasi, M., Kamatou, G.P.P., Baranska, M., Viljoen, A.M. 2010. Application of vibrational spectroscopy in the quality assessment of Buchu oil obtained from two commercially important Agathosma species (Rutaceae). South African Journal of Botany 76: 692–700. Doi: https://doi.org/10.1016/j.sajb.2010.07.013
- Suliman, S., Van Vuuren, S.F., Viljoen, A.M. 2010.Validating the in vitro antimicrobial activity of Artemisia afra in polyherbal combinations to treat respiratory infections. South African Journal of Botany 76: 655–661. Doi: https://doi.org/10.1016/j.sajb.2010.07.003
- Lalli, J.Y.Y., Viljoen, A.M., Van Vuuren, S.F. 2010. Potential interaction between the volatile and non-volatile fractions on the in vitro antimicrobial activity of three South African Pelargonium (Geraniaceae) species. Natural Product Communications 5: 1395–1400. Doi: https://doi.org/10.1177/1934578X1000500911
- Vermaak, I., Viljoen A.M., Hamman, J.H., Baranska, M. 2010. The potential application of FT-Raman spectroscopy for the quantification and mapping of the steroidal glycoside P57 in Hoodia gordonii. Phytochemistry Letters 3: 156–160. Doi: https://doi.org/10.1016/j.phytol.2010.06.003
- Van Zyl, R.L., Seatholo, S., Van Vuuren, S.F, Viljoen, A.M. 2010. Pharmacological interactions of essential oil constituents on the viability of micro-organisms. Natural Product Communications 5: 1381–1386. Doi: https://doi.org/10.1177/1934578X1000500909
- Van Vuuren, S.F., Kamatou, G.P.P., Viljoen, A.M. 2010. Volatile composition and antimicrobial activity of twenty commercial frankincense essential oil samples. South African Journal of Botany 76: 686–691. Doi: https://doi.org/10.1016/j.sajb.2010.06.001
- Chen, W., Viljoen, A.M. 2010. Geraniol – a review of a commercially important fragrance material. South African Journal of Botany 76: 643–651. Doi: https://doi.org/10.1016/j.sajb.2010.05.008
- Lu, Z., Chen, W., Viljoen A.M., Hamman, J.H. 2010. Effect of sinomenine on the in vitro intestinal epithelial transport of selected compounds. Phytotherapy Research 24: 211–218. Doi: https://doi.org/10.1002/ptr.2914
- Meades, G., Henken, R.L., Waldrop, G.L., Rahman, M., Gilman, D., Kamatou, G.P.P., Viljoen, A.M., Gibbons, S. 2010. Constituents of cinnamon inhibit bacterial acetyl CoA carboxylase. Planta Medica 76: 1570–1575. Doi: https://doi.org/10.1055/s-0030-1249778
- Jurgens, A., Viljoen, A. 2010. Chemical diversity and biological functions of plant volatiles. South African Journal of Botany, 76(4): 607–611. Doi: https://doi.org/10.1016/j.sajb.2010.09.008
- Kamatou, G.P.P, Viljoen, A.M., Özek, T., Başer, K.H.C. 2010. Chemical composition of the wood and leaf oils from the “Clanwilliam Cedar” (Widdringtonia cedarbergensis J.A. Marsh): a critically endangered species. South African Journal of Botany 76: 652–654. Doi: https://doi.org/10.1016/j.sajb.2010.04.002
- Vermaak, I., Hamman, J.H., Viljoen A.M. 2010. A rapid spectroscopic method for quantification of P57 in Hoodia gordonii raw material. Food Chemistry 120: 940–944. Doi: https://doi.org/10.1016/j.foodchem.2009.11.017
- Kamatou, G.P.P., Viljoen, A.M. 2010. A review of the application and pharmacological properties of α-bisabolol and α-bisabolol-rich oils. Journal of the American Oil Chemists Society 87: 1–7. Doi: https://doi.org/10.1007/s11746-009-1483-3
- Sandasi, M., Leonard, C.M., Viljoen, A.M. 2010. The in vitro anti-biofilm activity of selected culinary herbs and medicinal plants against Listeria monocytogenes. Letters in Applied Microbiology 50: 30–35. Doi: https://doi.org/10.1111/j.1472-765X.2009.02747.x
- Hulley, I.M., Viljoen A.M., Tilney, P.M., Van Vuuren, S.F., Kamatou, G.P.P., Van Wyk, B-E. 2010. Ethnobotany, leaf anatomy, essential oil composition and antibacterial activity of Pteronia onobromoides (Asteraceae). South African Journal of Botany 76: 43–48. Doi: https://doi.org/10.1016/j.sajb.2009.06.012
- Kamatou, G.P.P., Viljoen, A.M., Steenkamp, P. 2010. Antioxidant, anti-inflammatory activities and HPLC analysis of South African Salvia species. Food Chemistry 119: 684–688. Doi: https://doi.org/10.1016/j.foodchem.2009.07.010
- Viljoen, A.M., Kamatou, G.P.P., Coovadia, Z.H., Özek, T., Başer, K.H.C. 2010. Rare sesquiterpenes from South African Pteronia species. South African Journal of Botany 76: 146–152. Doi: https://doi.org/10.1016/j.sajb.2009.07.012
- Vermaak, I., Hamman, J.H., Viljoen A.M. 2010. High performance thin layer chromatography as a method to authenticate Hoodia gordonii raw material and products. South African Journal of Botany 76: 119–124. Doi: https://doi.org/10.1016/j.sajb.2009.09.011
2000 - 2009
- Beneke, C.E., Viljoen, A.M., Hamman, J.H. 2009. Polymeric plant-derived excipients in drug delivery. Molecules 14: 2602–2620. Doi: https://doi.org/10.3390/molecules14072602
- Vermaak, I., Viljoen A.M., Hamman, J.H., Van Vuuren S.F. 2009. Effect of simulated gastrointestinal conditions and epithelial transport on extracts of green tea and sage. Phytochemistry Letters 2: 166–170. Doi: https://doi.org/10.1016/j.phytol.2009.05.004
- Van Vuuren, S.F., Viljoen, A.M. 2009. Interaction between the non-volatile and volatile fractions on the antimicrobial activity of Tarchonanthus camphoratus. South African Journal of Botany 75: 505–509. Doi: https://doi.org/10.1016/j.sajb.2009.04.005
- Vermaak, I., Viljoen A.M., Hamman, J.H., Van Vuuren S.F. 2009. The effect of simulated gastrointestinal conditions on the antimicrobial activity and chemical composition of indigenous South African plant extracts. South African Journal of Botany 75: 594–599. Doi: https://doi.org/10.1016/j.sajb.2009.02.180
- Van Vuuren S.F., Suliman S., Viljoen A.M. 2009. The antimicrobial activity of four commercial essential oils in combination with conventional antimicrobials. Letters in Applied Microbiology 48: 440–446. Doi: https://doi.org/10.1111/j.1472-765X.2008.02548.x
- Chen, W., Lu, Z., Viljoen, A.M., Hamman, J.H. 2009. Intestinal drug transport enhancement by Aloe vera. Planta Medica 75: 587–595. Doi: https://doi.org/10.1055/s-0029-1185341
- Ojewole, E., Mackraj, I., Akhundov, K., Hamman, J.H., Viljoen, A.M., Govender T. 2009. Exploring the effect of Aloe vera gel on the buccal permeability of didanosine: permeability and histomorphological studies. Journal of Pharmacy and Pharmacology 61 (Supplement 1): A34–A35. Doi: https://doi.org/10.1055/s-0031-1280431
- Braithwaite, M., Van Vuuren, S.F., Viljoen, A.M. 2008. Validation of smoke inhalation therapy to treat microbial infections. Journal of Ethnopharmacology 119: 501–506. Doi: https://doi.org/10.1016/j.jep.2008.07.050
- Gericke, N., Viljoen, A.M. 2008. Sceletium – a review update. Journal of Ethnopharmacology 119: 653–663. Doi: https://doi.org/10.1016/j.jep.2008.07.043
- Kamatou, G.P.P., Viljoen, A.M., Özek, T., Başer, K.H.C. 2008. Head-space volatiles of Gethyllis afra and G. ciliaris fruits (“kukumakranka”). South African Journal of Botany 74: 768–770. Doi: https://doi.org/10.1016/j.sajb.2008.07.002
- Moolla, A., Viljoen, A.M. 2008. ‘Buchu’ – Agathosma betulina and A. crenulata (Rutaceae): A review. Journal of Ethnopharmacology 119: 413–419. Doi: https://doi.org/10.1016/j.jep.2008.07.036
- Nyiligira, E., Viljoen, A.M., Van Heerden, F.R., Van Zyl, R.L., Van Vuuren, S.F., Steenkamp, P.A. 2008. Phytochemistry and in vitro pharmacological activities of South African Vitex (Verbenaceae) species. Journal of Ethnopharmacology 119: 680–685. Doi: https://doi.org/10.1016/j.jep.2008.07.004
- Van Vuuren, S.F., Viljoen, A.M. 2008. In vitro evidence of phyto-synergy for plant part combinations of Croton gratissimus (Euphorbiaceae) used in African traditional healing. Journal of Ethnopharmacology 119: 700–704. Doi: https://doi.org/10.1016/j.jep.2008.06.031
- Kamatou, G.P.P., Makunga, N.P., Ramogola, W.P.N., Viljoen, A.M. 2008. South African Salvia species: A review of biological activities and phytochemistry. Journal of Ethnopharmacology 119: 664–672. Doi: https://doi.org/10.1016/j.jep.2008.06.030
- Paraskeva, M.P., Van Vuuren, S.F., Van Zyl, R.L., Davids, H., Viljoen, A.M. 2008. The in vitro biological activity of selected South African Commiphora species. Journal of Ethnopharmacology 119: 673–679. Doi: https://doi.org/10.1016/j.jep.2008.06.029
- Essop, A.B., Van Zyl, R.L., Van Vuuren, S.F., Mulholland, D., Viljoen, A.M. 2008. The in vitro pharmacological activities of 12 South African Hermannia species. Journal of Ethnopharmacology 119: 615–619. Doi: https://doi.org/10.1016/j.jep.2008.06.026
- Lourens, A.C.U., Viljoen, A.M., Van Heerden, F.R. 2008. South African Helichrysum species: A review of the traditional uses, biological activity and phytochemistry. Journal of Ethnopharmacology 119: 630–652. Doi: https://doi.org/10.1016/j.jep.2008.06.011
- Kamatou, G.P.P., Viljoen, A.M. 2008. Linalool – a review of a biologically active compound of commercial importance. Natural Product Communications 3: 1183–1192. Doi: https://doi.org/10.1177/1934578X0800300727
- Erasto, P., Viljoen, A.M. 2008. Limonene: biosynthetic, ecological and pharmacological relevance. Natural Product Communications 3: 1193–1202. Doi: https://doi.org/10.1177/1934578X08003007
- Kamatou, G.P.P., Van Zyl, R.L., Davids, H., Van Vuuren, S.F., Viljoen, A.M. 2008. Synergistic and antagonistic interactions of essential oils on the biological activities of the solvent extracts from three Salvia species. Natural Product Communications 3: 1111–1115. Doi: https://doi.org/10.1177/1934578X08003007
- Sandasi, M., Leonard, C.M., Viljoen, A.M. 2008. The effect of five common essential oil components on Listeria monocytogenes biofilms. Food Control 19: 1070–1075. Doi: https://doi.org/10.1016/j.foodcont.2007.11.006
- Lalli, J.Y.Y., Van Zyl, R.L., Van Vuuren, S.F., Viljoen, A.M. 2008. In vitro biological activities of South African Pelargonium (Geraniaceae) species. South African Journal of Botany 74: 153–157. Doi: https://doi.org/10.1016/j.sajb.2007.08.011
- Kamatou, G.P.P., Van Zyl, R.L., Davids, H., Van Heerden, F.R., Lourens, A.C.U., Viljoen, A.M. 2008. Antimalarial and anticancer activities of selected South African Salvia species and isolated compounds from S. radula. South African Journal of Botany 74: 238–243. Doi: https://doi.org/10.1016/j.sajb.2007.08.001
- Kamatou, G.P.P., Van Zyl, R.L., Figueiredo, A.C, Barroso, J.G., Pedro, L.G., Van Vuuren, S.F. Viljoen, A.M. 2008. Seasonal variation in essential oil composition, oil toxicity and the biological activity of solvent extracts of three South African Salvia species. South African Journal of Botany 74: 230–237. Doi: https://doi.org/10.1016/j.sajb.2007.08.002
- Huang, M., Du Plessis, J., Du Preez, J., Hamman, J., Viljoen A.M. 2008. Transport of aspalathin, a Rooibos tea flavonoid, across the skin and intestinal epithelium. Phytotherapy Research 22: 699–704. Doi: https://doi.org/10.1002/ptr.2422
- Viljoen, A.M., Kamatou, G.P.P., Başer, K.H.C. 2008. Head-space volatiles of Marula (Sclerocarya birrea subsp. caffra). South African Journal of Botany 74: 325–326. Doi: https://doi.org/10.1016/j.sajb.2007.10.005
- Frum, Y., Viljoen, A.M., Van Heerden, F.R. 2007. Verbascoside and luteolin-5-O-β-d-glucoside isolated from Halleria lucida L. exhibit antagonistic anti-oxidant properties in vitro. South African Journal of Botany 73: 583–587. Doi: https://doi.org/10.1016/j.sajb.2007.05.006
- Kamatou, G.P.P., Van Vuuren, S.F., Van Heerden, F.R., Seaman, T. Viljoen, A.M. 2007. Antibacterial and antimycobacterial activities of South African Salvia species and isolated compounds from S. chamelaeagnea. South African Journal of Botany 73: 552–557. Doi: https://doi.org/10.1016/j.sajb.2007.05.001
- Moolla, A., Van Vuuren, S.F., Van Zyl, R.L., Viljoen, A.M. 2007. Biological activity and toxicity profile of Agathosma (Rutaceae) species. South African Journal of Botany 73: 588–592. Doi: https://doi.org/10.1016/j.sajb.2007.05.007
- Kamatou, G.P.P., Viljoen, A.M., Figueiredo, A.C., Tilney, P.M., Van Zyl, R.L., Barroso, J.G., Pedro, L.G., Van Vuuren, S.F. 2007. Trichomes, essential oil composition and biological activities of Salvia albicaulis Benth. and S. dolomitica Codd, two species from the Cape region of South Africa. South African Journal of Botany 73: 102–108. Doi: https://doi.org/10.1016/j.sajb.2006.08.001
- Van Vuuren, S.F., Viljoen, A.M. 2007. Antimicrobial activity of limonene enantiomers and 1,8-cineole alone and in combination. Flavour and Fragrance Journal 22: 540–544. Doi: https://doi.org/10.1002/ffj.1843
- Van Vuuren, S.F., Viljoen, A.M., Özek, T., Demirci, B., Başer, K.H.C. 2007. Seasonal and geographical variation of Heteropyxis natalensis essential oil and the effect thereof on the antimicrobial activity. South African Journal of Botany 73: 441–448. Doi: https://doi.org/10.1016/j.sajb.2007.03.010
- Van Vuuren S.F., Viljoen, A.M., Van Zyl, R.L., Van Heerden, F.R., Başer K.H.C. 2006. The antimicrobial, antimalarial and toxicity profiles of helihumulone, leaf essential oil and extracts of Helichrysum cymosum (L.) D.Don subsp. cymosum. South African Journal of Botany 72: 287–290. Doi: https://doi.org/10.1016/j.sajb.2005.07.007
- Viljoen, A.M., Demirci, B., Başer, K.H.C., Potgieter, C.J., Edwards, T.J. 2006. Microdistillation and essential oil chemistry – a useful tool for detecting hybridisation in Plectranthus (Lamiaceae). South African Journal of Botany 72: 99–104. Doi: https://doi.org/10.1016/j.sajb.2005.05.003
- Kamatou, G.P.P., Viljoen A.M., Van Vuuren S.F., Van Zyl, R.L. 2006. In vitro evidence of antimicrobial synergy between Salvia chamelaeagnea and Leonotis leonurus. South African Journal of Botany 72: 634–636. Doi: https://doi.org/10.1016/j.sajb.2006.03.011
- Van Zyl, R.L., Seatholo, S., Van Vuuren, S.F., Viljoen, A.M. 2006. The biological activities of twenty nature identical essential oil constituents. Journal of Essential Oil Research 18: 129–133. Doi: https://doi.org/10.1080/10412905.2006.12067134
- Frum, Y., Viljoen, A.M. 2006. In vitro 5-lipoxygenase activity of three indigenous South African aromatic plants used in traditional healing and the stereospecific activity of limonene in the 5-lipoxygenase assay. Journal of Essential Oil Research 18: 85–88. Doi: https://doi.org/10.1080/10412905.2006.12067127
- Viljoen, A.M., Van Vuuren, S.F., Gwebu, L., Demirci, B., Başer, K.H.C. 2006. The geographical variation and antimicrobial activity of African Wormwood (Artemisia afra) essential oil. Journal of Essential Oil Research 18: 19–25. Doi: https://doi.org/10.1080/10412905.2006.12067114
- Van Vuuren, S.F., Viljoen, A.M. 2006. A Comparative Investigation of the Antimicrobial Properties of Indigenous South African Aromatic Plants with Popular Commercially Available Essential Oils. Journal of Essential Oil Research 18: 66– Doi: https://doi.org/10.1080/10412905.2006.12067124
- Viljoen, A.M., Moolla, A., Başer, K.H.C., Demirci, B., Özek, T., Van Vuuren, S.F., Van Zyl, R.L. 2006. The biological activity and essential oil composition of seventeen Agathosma (Rutaceae) species. Journal of Essential Oil Research 18: 2–16. Doi: https://doi.org/10.1080/10412905.2006.12067112
- Başer, K.H.C., Demirci, B., Özek, T., Khusal, P., Viljoen, A.M., Victor, J. 2006. Composition of the essential oils of five Coleonema species from South Africa. Journal of Essential Oil Research 18: 26–29. Doi: https://doi.org/10.1080/10412905.2006.12067115
- Başer, K.H.C., Demirci, B., Özek, T., Viljoen, A.M., Victor, J. 2006. Composition of the essential oils of three Acmadenia species from South Africa. Journal of Essential Oil Research 18: 54–56. Doi: https://doi.org/10.1080/10412905.2006.12067121
- Başer, K.H.C., Demirci, B., Özek, T., Viljoen, A.M., Victor, J. 2006. Composition of the essential oils of two Adenandra species from South Africa. Journal of Essential Oil Research 18: 46–47. Doi: https://doi.org/10.1080/10412905.2006.12067118
- Başer, K.H.C., Demirci, B., Özek, T., Viljoen, A.M., Victor, J.E. 2006. Composition of the essential oil of Diosma prama Williams. Journal of Essential Oil Research 18: 17–18. Doi: https://doi.org/10.1080/10412905.2006.12067113
- Başer, K.H.C., Demirci, B., Özek, T., Viljoen, A.M. Composition of the essential oil of Euchaetis albertiniana I.J.M. Williams. Journal of Essential Oil Research 18: 122–123. Doi: https://doi.org/10.1080/10412905.2006.12067132
- Njenga, E.W., Viljoen, A. 2006. In vitro 5-lipoxygenase inhibition and anti-oxidant activity of Eriocephalus (Asteraceae) species. South African Journal of Botany, 72(4) 637–641. Doi: https://doi.org/10.1016/j.sajb.2006.03.007
- Frum, Y., Viljoen, A.M. In vitro 5-lipoxygenase and anti-oxidant activities of South African medicinal plants commonly used topically for skin diseases. Skin Physiology and Pharmacology 19: 329–335. Doi: https://doi.org/10.1159/000095253
- Van Vuuren, S.F., Viljoen, A.M. The in vitro antimicrobial efficacy of African toothbrush sticks. South African Journal of Botany 72: 646–648. Doi: https://doi.org/10.1016/j.sajb.2006.03.009
- Viljoen, A.M., Gono-Bwalya, A., Kamatou, G., Başer, K.H.C., Demirci, B. 2006. The essential oil composition and chemotaxonomy of Salvia stenophylla and its allies repens and S. runcinata. Journal of Essential Oil Research 18: 37–45. Doi: https://doi.org/10.1080/10412905.2006.12067117
- Viljoen, A.M., Petkar, S., Van Vuuren, S.F., Figueiredo, A.C., Pedro, L.G., Barroso, J.G. 2006. The chemo-geographical variation in essential oil composition and the antimicrobial properties of “wild mint” – Mentha longifolia polyadena (Lamiaceae) in southern Africa. Journal of Essential Oil Research 18: 60–65. Doi: https://doi.org/10.1080/10412905.2006.12067123
- Lalli, J., Viljoen, A.M., Başer, K.H.C., Demirci, B., Özek, T. 2006. The essential oil composition and chemotaxonomical appraisal of South African Pelargoniums (Geraniaceae). Journal of Essential Oil Research 18: 89–105. Doi: https://doi.org/10.1080/10412905.2006.12067128
- Kamatou, G., Van Zyl, R.L., Van Vuuren, S.F., Viljoen, A.M., S.F., Figueiredo, A.C., Barroso, J.G., Pedro, L.G. 2006. Chemical composition, leaf trichome types and biological activities of the essential oils of four related Salvia species indigenous to southern Africa. Journal of Essential Oil Research 18: 72–79. Doi: https://doi.org/10.1080/10412905.2006.12067125
- Viljoen, A.M., Moolla, A., Van Vuuren, S.F., Başer, K.H.C., Demirci, B., Özek, T. 2006. A seasonal variation study of the chemical composition and antimicrobial activity of the essential oil of Agathosma ovata (Thunb.) Pillans (Rutaceae). Journal of Essential Oil Research 18: 30–36. Doi: https://doi.org/10.1080/10412905.2006.12067116
- Viljoen, A.M., Njenga, E.W., Van Vuuren, S.F., Bicchi, C., Rubiolo, P., Sgorbini, B. 2006. Essential oil composition and in vitro biological activities of seven Namibian species of Eriocephalus (Asteraceae). Journal of Essential Oil Research 18: 124–128. Doi: https://doi.org/10.1080/10412905.2006.12067133
- Kamatou, G., van Zyl, R.L., Van Vuuren, S.F., Viljoen, A.M., S.F., Figueiredo, A.C., Barroso, J.G., Pedro, L.G. 2006. Biological activities and composition of Salvia muirii Bol. essential oil. Journal of Essential Oil Research 18: 48–51. Doi: https://doi.org/10.1080/10412905.2006.12067119
- Drewes, S.E., Mudau, K.E., Van Vuuren, S.F., Viljoen, A.M. Antimicrobial monomeric and dimeric diterpenes from the leaves of Helichrysum tenax var tenax. Phytochemistry 67: 716–722. Doi: https://doi.org/10.1016/j.phytochem.2005.12.015
- Frum, Y., Viljoen, A.M., Drewes, S.E. 2005. In vitro 5-lipoxygenase and anti-oxidant activities of Warburgia salutaris and drimane sesquiterpenoids. South African Journal of Botany 71: 447–449. Doi: https://doi.org/10.1016/S0254-6299(15)30119-8
- Drewes, S.E., Khan, F., Van Vuuren, S.F., Viljoen, A.M. Simple 1,4-benzoquinones with antibacterial activity from stems and leaves of Gunnera perpensa. Phytochemistry 66: 1812–1816. Doi: https://doi.org/10.1016/j.phytochem.2005.05.024
- Kamatou, G.P.P., Viljoen, A.M., Gono-Bwalya, A.B., Van Zyl, R.L., Van Vuuren, S.F., Lourens, A., Başer, K.H.C., Demirci, B., Steenkamp, P. 2005. In vitro pharmacological activities and a chemical investigation of three South African Salvia Journal of Ethnopharmacology 102: 382–390. Doi: https://doi.org/10.1016/j.jep.2005.06.034
- Njenga, E.W., Van Vuuren S.F., Viljoen, A.M. Antimicrobial activity of Eriocephalus L. species. South African Journal of Botany 71: 81–87. Doi: https://doi.org/10.1016/S0254-6299(15)30153-8
- Viljoen, A.M., Subramoney, S., Van Vuuren, S.F., Başer, K.H.C., Demirci, B. 2005. The composition, geographical variation and antimicrobial activity of Lippia javanica (Verbenaceae) leaf essential oils. Journal of Ethnopharmacology 96: 271–277. Doi: https://doi.org/10.1016/j.jep.2004.09.017
- Jäger, A.K., Mohoto, S.P., Van Heerden, F.R., Viljoen, A.M. Activity of a traditional South African epilepsy remedy in the GABA-benzodiazepine receptor assay. Journal of Ethnopharmacology 96: 603–606. Doi: https://doi.org/10.1016/j.jep.2004.10.005
- Lourens, A.C.U., Reddy, D., Başer, K.H.C., Viljoen, A.M., Van Vuuren, S.F. 2004. In vitro biological activity and essential oil composition of four indigenous South African Helichrysum Journal of Ethnopharmacology 95: 253–258. Doi: https://doi.org/10.1016/j.jep.2004.07.027
- Nyiligira, E., Viljoen, A.M., Başer, K.H.C., Van Vuuren, S.F. 2004. Essential oil composition and in vitro antimicrobial and anti-inflammatory activity of South African Vitex South African Journal of Botany 70: 611–617. Doi: https://doi.org/10.1016/S0254-6299(15)30199-X
- Joulain, D., Casazza, A., Laurent, R., Portier, D., Pandya, R., Le, M., Viljoen, A.M. Volatile Flavor Constituents of Fruits from Southern Africa: Mobola Plum (Parinari curatellifolia). Journal of Agricultural and Food Chemistry 52: 2322–2325. Doi: https://doi.org/10.1021/jf030702i
- Sibanda, W., Pillay, V., Danckwerts, M.P., Viljoen, A.M., Van Vuuren, S.F., Riaz, A. 2004. Experimental Design for the fomulation and optimization of novel cross-linked oilispheres developed for in vitro site specific release of Mentha piperita AAPS PharmSciTech 5: 1–14. Doi: https://doi.org/10.1208/pt050118
- Lindsey, K.L., Viljoen A.M., Jäger, A.K. 2003. Screening of Aloe species for antioxidant activity. South African Journal of Botany 69: 599–602. Doi: https://doi.org/10.1016/S0254-6299(15)30302-1
- Viljoen, A.M., Van Vuuren, S., Ernst, E., Klepser, M.J., Demirci, B., Başer, K.H.C., Van Wyk, B.E. 2003. Osmitopsis asteriscoides (Asteraceae) – The antimicrobial activity and essential oil composition of a Cape-Dutch remedy. Journal of Ethnopharmacology 88: 137–143. Doi: https://doi.org/10.1016/S0378-8741(03)00191-0
- Karagianis, G., Viljoen, A.M., Waterman, P.G. 2003. Identification of major metabolites in Aloe littoralis by liquid chromatography-nuclear magnetic resonance spectroscopy. Phytochemical Analysis 14: 275–280. Doi: https://doi.org/10.1002/pca.714
- Van Heerden, F.R., Van Wyk, B-E., Viljoen, A.M., Steenkamp, P.A. 2003. Phenolic variation in wild populations of Aspalathus linearis (rooibos tea). Biochemical Systematics and Ecology 31: 885–895. Doi: https://doi.org/10.1016/S0305-1978(03)00084-X
- Huffman, A., Klepser, M.E., Ernst, E.J., Keele, D., Roling, E., Viljoen, A.M. Susceptibility of opportunistic bacteria and yeasts to the volatile oils of Artemisia afra, Lippia javanica, Lippia scaberrima, Myrothamnus flabellifolius and Osmitopsis asteriscoides. The Journal of Infectious Disease Pharmacotherapy 5: 43–50. Doi: https://doi.org/10.1300/J100v05n04_04
- Viljoen, A.M., Demirci, B., Başer, K.H.C., Van Wyk, B.-E. 2002. The essential oil composition of the roots and Rhizomes of Siphonochilus aethiopicus (wild ginger). South African Journal of Botany 68: 115–116. Doi: https://doi.org/10.1016/S0254-6299(16)30467-7
- Van Heerden, F.R., Viljoen, A.M., Mohoto, S. 2002. A phytochemical investigation of Craterocapsa tarsodes, a plant used for the treatment of epilepsy by the Northern Sotho people of South Africa. South African Journal of Botany 68: 77–79. Doi: https://doi.org/10.1016/S0254-6299(16)30459-8
- Viljoen, A.M., Klepser, M.J., Ernst, E., Keele, D., Roling, E., Van Vuuren, S., Demirci, B., Başer, K.H.C., Van Wyk, B.E. 2002. The composition and antimicrobial activity of the essential oil of the resurrection bush, Myrothamnus flabellifolius. South African Journal of Botany 68: 100–105. Doi: https://doi.org/10.1016/S0254-6299(16)30464-1
- Van Zyl, R.L., Viljoen, A.M. In vitro activity of Aloe extracts against Plasmodium falciparum. South African Journal of Botany 68: 106–110. Doi: https://doi.org/10.1016/s0254-6299(15)30451-8
- Lindsey, K.L., Jäger, A.K., Viljoen, A. 2002. Cyclooxygenase inhibitory activity of Aloes. South African Journal of Botany 68: 47–50. Doi: https://doi.org/10.1016/S0254-6299(16)30453-7
- Viljoen, A.M., Van Wyk, B-E., Van Heerden, F.R. 2002. The chemotaxonomic value of the diglucoside anthrone homonataloside B in the genus Biochemical Systematics and Ecology 30: 35–43. Doi: https://doi.org/10.1016/S0305-1978(01)00061-8
- Viljoen, A.M., Van Wyk, B-E. 2001. A chemotaxonomic and morphological appraisal of Aloe series Purpurascentes, Aloe section Anguialoe and their hybrid, Aloe Biochemical Systematics and Ecology 30: 1–11. Doi: https://doi.org/10.1016/S0305-1978(00)00095-8
- Viljoen, A.M., Van Wyk, B-E., Newton, L.E. 2001. The occurrence and taxonomic distribution of the anthrones aloin, aloinoside and microdontin in Aloe. Biochemical Systematics and Ecology 29: 53–67. Doi: https://doi.org/10.1016/S0305-1978(00)00024-7
- Dagne, E., Bisrat, D., Van Wyk, B-E., Viljoen, A.M. Chromones and anthrones from Aloe marlothii and Aloe rupestris. Phytochemistry 55: 949–952. Doi: https://doi.org/10.1016/S0031-9422(00)00328-9
- Dagne, E., Bisrat, D., Viljoen, A.M., Van Wyk, B-E. 2000. The chemistry of Aloe species – a review. Current Organic Chemistry 4: 1055–1078. Doi: https://doi.org/10.2174/1385272003375932
- Van Heerden, F.R., Viljoen, A.M., Van Wyk, B-E. 2000. The major flavonoid of Dodonaea angustifolia. Fitoterapia 71: 602–604. Doi: https://doi.org/10.1016/S0367-326X(00)00201-X
- Van Heerden, F.R., Viljoen, A.M., Van Wyk, B-E. 2000. 6’-O-Coumaroylaloesin from Aloe castanea – A taxonomic marker for Aloe section Anguialoe. Phytochemistry 55: 117–120. Doi: https://doi.org/10.1016/S0031-9422(00)00252-1
- Viljoen, A.M., Van Wyk, B-E. 2000. The chemotaxonomic value of the phenyl pyrone, aloenin in the genus Aloe. Biochemical Systematics and Ecology 28: 1009–1017. Doi: https://doi.org/10.1016/S0305-1978(00)00018-1
1993 - 1999
- Viljoen, A.M., Van Wyk, B-E. 1999. The chemotaxonomic value of two cinnamoyl chromones aloeresins E and F in Aloe. Taxon 48: 747–754. Doi: https://doi.org/10.2307/1223645
- Viljoen, A.M., Van Wyk, B-E., Newton, L.E. 1999. Plicataloside in Aloe – a chemotaxonomic appraisal. Biochemical Systematics and Ecology 27: 507–517. Doi: https://doi.org/10.1016/S0305-1978(98)00111-2
- Viljoen, A.M., Van Wyk, B-E., Van Heerden, F.R. 1998. The distribution and chemotaxonomic significance of flavonoids in the genus Plant Systematics and Evolution 211: 31–42. Doi: https://doi.org/10.1007/BF00984910
- Dagne, E., Bisrat, D., Van Wyk, B–E., Viljoen, A. 1998. 10‑Hydroxyaloin‑B 6’‑O‑acetate, an oxanthrone from Aloe claviflora. Journal of Natural Products 61: 256–257. Doi: https://doi.org/10.1021/np970368i
- Dagne, E., Bisrat, D., Van Wyk, B-E., Viljoen, A.M., Hellwig, V., Steglich, W. 1997. Anthrones from Aloe microstigma. Phytochemistry 44: 1271–1274. Doi: https://doi.org/10.1016/S0031-9422(96)00710-8
- Van Heerden, F.R., Van Wyk B-E., Viljoen, A.M. 1996. Aloeresins E & F, two chromones from Aloe peglerae. Phytochemistry 43: 867–869. Doi: https://doi.org/10.1016/0031-9422(96)00302-0
- Viljoen, A.M., Van Wyk, B-E., Dagne, E. 1996. The chemotaxonomic value of 10-hydroxyaloin and its derivatives in Aloe series Asperifoliae Kew Bulletin 51: 159–168. Doi: https://doi.org/10.2307/4118753
- Viljoen, A.M., Van Wyk, B-E., Van der Bank, H., Smith, G.F., Van der Bank, M. 1996. A chemotaxonomic and biochemical evaluation of the identity of Aloe candelabrum. (Aloaceae). Taxon 45: 461–471. Doi: https://doi.org/10.2307/1224138
- Smith, G.F., Van Wyk, B-E., Mössmer, M., Viljoen, A.M. 1995. The taxonomy of Aloinella, Guillauminia and Lemeea. (Aloaceae). Taxon 44: 513–517. Doi: https://doi.org/10.2307/1223496
- Viljoen, A.M., Demarne, F.E., Van Der Walt, J.J.A., Swart, J.P.J. 1995. A study of the variation in the essential oil and macromorphology of Pelargonium capitatum (L.) L’Herit. (Geraniaceae). Part 3. Geographical variation in essential oil composition and floral structure. South African Journal of Botany 61: 105–113. Doi: https://doi.org/10.1016/S0254-6299(15)30496-8
- Viljoen, A.M., Demarne, F.E., Van Der Walt, J.J.A., Swart, J.P.J. 1995. A study of the variation in the essential oil and morphology of Pelargonium capitatum (L.) L’Herit. (Geraniaceae). Part 2. The chemotypes of capitatum. Journal of Essential Oil Research 7: 605–611. Doi: https://doi.org/10.1080/10412905.1995.9700514
- Demarne, F.E., Viljoen, A.M., Van Der Walt, J.J.A. 1993. A study of the variation in the essential oil and morphology of Pelargonium capitatum (L.) L’Herit. (Geraniaceae). Part 1. The composition of the oil. Journal of Essential Oil Research 5: 493–499. Doi: https://doi.org/10.1080/10412905.1993.9698269