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Item An updated review of Adansonia digitata: A commercially important African tree.(Elsevier B.V., 2011-08-01) Kamatou, G.P.P.; Vermaak, I.; Viljoen, A.M.Adansonia digitata L. (Malvaceae) is a majestic tree revered in Africa for its medicinal and nutritional value. The plant parts are used to treat various ailments such as diarrhoea, malaria and microbial infections. It is reported that it is an excellent antioxidant due to the vitamin C content which is seven to ten times higher than the vitamin C content of oranges. Baobab has numerous biological properties including antimicrobial, antiviral, antioxidant and anti-inflammatory activities amongst others. Phytochemical investigation revealed the presence of flavonoids, phytosterols, amino acids, fatty acids, vitamins and minerals. The seeds are a source of significant quantities of lysine, thiamine, calcium and iron. Baobab is an important commodity which is integral to the livelihood of rural communities. In addition, the global demand for baobab raw material (e.g. seed oil, fruit pulp) by the food and beverage, nutraceutical and cosmetic industries has increased dramatically in recent years thereby increasing the commercial value and importance of this coveted African tree. In the past few years, there has been an increased demand for non-timber forest products (NTFPs), specifically baobab seed oil for inclusion in cosmetic formulations due to its high fatty acid composition. This review summarises the botanical aspects, ethnobotany, phytochemistry, biological properties and most importantly the nutritional value and commercial importance of baobab products.Item The in vitro antimicrobial evaluation of commercial essential oils and their combinations against acne.(Wiley, 2018-03-01) Orchard, A.; Van Vuuren, S.F.; Viljoen, A.M.; Kamatou, G.OBJECTIVE: The study investigated the efficacy of commercial essential oil combinations against the two pathogens responsible for acne with the aim to identify synergy and favourable oils to possibly use in a blend. MATERIALS AND METHODS: Antimicrobial activity was assessed using the minimum inhibitory concentration (MIC) assay against Staphylococcus epidermidis (ATCC 2223) and Propionibacterium acnes (ATCC 11827), and the fractional inhibitory concentration index (ΣFIC) was calculated. Combinations displaying synergistic interactions were further investigated at varied ratios and the results plotted on isobolograms. RESULTS: From the 408 combinations investigated, 167 combinations were identified as displaying noteworthy antimicrobial activity (MIC value ≤1.00 mg mL1). Thirteen synergistic interactions were observed against S. epidermidis, and three synergistic combinations were observed against P. acnes. It was found that not one of the synergistic interactions identified were based on the combinations recommended in the layman’s aroma-therapeutic literature. Synergy was evident rather from leads based on antimicrobial activity from previous studies, thus emphasizing the importance of scientific validation. Leptospermum scoparium J.R.Forst. and G.Forst (manuka) was the essential oil mostly involved in synergistic interactions (four) against S. epidermidis. Cananga odorata (Lam.) Hook.f. and Thomson (ylang ylang) essential oil was also frequently involved in synergy where synergistic interactions could be observed against both pathogens. The combination with the lowest MIC value against both acne pathogens was Vetiveria zizanioides Stapf (vetiver) with Cinnamomum verum J.Presl (cinnamon bark) (MIC values 0.19–0.25 mg mL1). Pogostemon patchouli Benth. (patchouli), V. zizanioides, C. verum and Santalum spp. (sandalwood) could be identified as the oils that contributed the most noteworthy antimicrobial activity towards the combinations. The different chemotypes of the essential oils used in the combinations predominantly resulted in similar antimicrobial activity. CONCLUSIONS: The investigated essential oil combinations resulted in at least 50% of the combinations displaying noteworthy antimicrobial activity. Most of the synergistic interactions do not necessarily correspond to the recommended layman’s aromatherapeutic literature, which highlights a need for scientific validation of essential oil antimicrobial activity. No antagonism was observed.Item Headspace analysis and characterisation of South African propolis volatile compounds using GCxGC–ToF–MS.(Elsevier Editora Ltda., 2018-12-04) Kamatou, Guy; Sandasi, Maxleene; Tankeu, Sidonie; Van Vuuren, Sandy; Viljoen, AlvaroPropolis also known as “bee glue or bee resin” is a resinous mixture of bee saliva or bee wax and exudate from tree trunks and flowers, produced by honeybees. The composition of propolis varies depending on the vegetation the bees can access. It is therefore expected that propolis obtained from various localities may have different chemical profiles. In this study, the headspace volatiles of propolis (n = 39) collected from various locations in South Africa (Gauteng, Northern Cape and Western Cape Provinces) were explored for the first time using GCxGC–ToF–MS. Several GCxGC parameters were optimised including incubation time, temperature and modulation period. Multivariate data analysis techniques (principal component and hierarchical cluster analyses) were applied on the GCxGC–ToF–MS data to investigate trends and clustering patterns within propolis samples. The results demonstrated that headspace volatiles of propolis varied between locations. The volatile profiles were dominated by monoterpenes such as-pinene (1.2–46.5%), -pinene (2.0–21.8%), dihydrosabinene (trace-17.8%), limonene (trace-11.6%),p-cymene (0.1–5.3%), 1,8-cineole (0.1–11.0%), 2,7-dimethyl-3-octen-5-yne (trace-11.7%), E--ocimene(trace-17.8%), octanal (trace-12.9%), styrene (trace-13.5%) and -thujene (trace-11.0%). Principal com-ponent analysis revealed chemical variation within propolis from the various locations. The heatmap of the averages revealed dehydrosabinene, isopropentyltoluene, p-cymene, acetophenone and -thujeneas chemical markers for the Northern Cape propolis, while -terpinene, propanoic acid, furfural, 2-methoxy benzyl alcohol and hexanoic acid methylester were filtered out as markers for Gauteng propolis. The propolis samples originating from the Western Cape Province were dominated by prenal, cinnamaldehyde styrene, 1,8-cineole, decanal, prenyl acetate and butanoic acid. Using GCxGC–ToF–MS in combination with chemometrics, it was possible to profile headspace volatile constituents of propolis and further identify marker compounds that differentiate propolis from various provinces in South Africa.