Variation in the essential oil constituents of Pteronia incana (Asteraceae)

The essential oil of Pteronia incana was collected and was investigated on a monthly basis using GCMS. The oil volume and its constituents vary greatly with different time of sampling and distillation. The oil contains a high percentage of myrcene a-pinene, b-pinene with sabinene, a-terpinene, 1.8 cineole and limonene

Chemical composition of volatile constituents from the leaves of Aloe ferox

Volatile compounds oils play a significant role in perfumery, cosmetic, medicinal and pharmaceutical industries. In our protracted research for new useful essential oils, a volatile oil from Aloe ferox was obtained by prolonged hydrodistillation. This volatile oil was subjected to GC/MS analysis to identify the major constituents of the oil. The major constituents identified were as follows: 3, 6 octatriene (23.86%), 3-cyclohexane-1-hetanol (7.31%), Bornylene (5.24%), 1, 3-cyclopentadiene (4.07) and 5-methyl- 3-heptanol (3.92%). A significant number of other volatiles were also identified but in minor concentrations

Identification of the Anti Listerial

Partially purified fractions of the n-hexane extract of Garcinia kola seeds were obtained through column chromatography and their constituents were identified through the use of gas chromatography coupled to mass spectrometry (GC-MS). Three fractions were obtained by elution with benzene as the mobile phase and silica gel 60 as the stationery phase and these were named Benz1, Benz2, and Benz3 in the order of their elution. The antiListerial activities of these fractions were assessed through MIC determination and only Benz2 and Benz3 were found to be active with MIC’s ranging from 0.625 to 2.5 mg/mL. The results of the GC-MS analysis showed Benz2 to have 9 compounds whilst Benz3 had 7 compounds, with the major compounds in both fractions being 9,19-Cyclolanost-24-en-3-ol, (3.β.) and 9,19-Cyclolanostan-3-ol,24-methylene-, (3.β.). The Benz2 fraction was found to have mainly indifferent interactions with ampicillin and penicillin G whilst mainly additive interactions were observed with ciprofloxacin. The Benz3 fraction’s interactions were found to be 50% synergistic with penicillin G and 25% synergistic with ciprofloxacin and ampicillin. A commercially available 9,19-Cyclolanost-24-en-3-ol, (3.β.) was found not to exhibit any antiListerial activities at maximum test concentrations of 5 mg/mL, suggesting that the compound could be acting in synergy with the other compounds in the eluted fractions of Garcinia kola seeds

Plant Cell Structure & Metabolism/Anatomy/Plant Kingdom and Ecology: BIO 111

Plant Cell Structure & Metabolism/Anatomy/Plant Kingdom and Ecology: BIO 111, examination June 2011

Plant Ecology/Physiology and Diversity: BOT 121

Plant Ecology/Physiology and Diversity: BOT 121, examination November 2009

Plant Ecology, Plant Physiology and Plant Diversity: BOT 121

Plant Ecology, Plant Physiology and Plant Diversity: BOT 121, supplementary examination January 2010

Plant Ecology, Plant Physiology and Plant Diversity: BOT 121

Plant Ecology, Plant Physiology and Plant Diversity: BOT 121, supplementary examination January 2012

The essential oil composition and antimicrobial activity of leaves of Schistostephium hippifolium

The essential oil from the leaves and branches of Schistostephium hippifolium were extracted by hydro-distillation during summer and winter months. Both essential oils were analyzed by gas chromatography- mass spectroscopy (GC-MS) respectively during their extracted period. Fourteen compounds were  identified from essential oil extracted during the February, summer month in South Africa. The volatile oil constituted about 99.31% of the total essential oil composition. The GC-MS reveals the following major constituents in the oil: Chrysanthenyl acetate (32.17%), 1.8-cineole (24.85%), ethanone, 1-  (1-cyclohexen-1-y1) (6.36%), camphor (6.02%), terpinen-4-ol (5.02%), á-pinene (5.13%),  germacrene-D (4.89%) bicyclogermacrene (4.38%), linalool L (2.04%), trans - caryophyllene (1.80%), ã-terpinene (1.95 %). In June, a winter month in South Africa, 48 volatile compounds from the essential oil of S. hippifolium were identified which constituted about 99.99% of the total composition of the  essential oil. The major compounds identified were the 1.8-cineole (18.31%), Germacrene-D (7.43%), bicyclogermacrene (5.24%), 3-cyclohexen-1-ol (6.78%), camphor (5.64%), bicyclogermacrene  (5.24%), á.-pinene (2.52%), â-caryophylle (2.11%), linalool L (3.35%), caryophyllene oxide (1.88%), spathulenol (1.62%) and ã-terpinene (1.39%). In both essential oils (summer and winter), minor volatiles were identified. However, they were in low concentration. The crude extract from the aerial parts of the plant were screened for antibacterial activity against five Gram-positive species  (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Micrococcus kristinae and Staphylococcus faecalis) and five Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Staphlococcus flexneri, Klebsiella pneumonia and Serratiaf marcescens) microorganisms. The minimum inhibitory concentration (MIC) values where highly active at values below two and less active at values above two. All the extracts tested displayed very good activity against both Gram-positive and  Gram-negative bacteria with MIC ranging between 0.098 to 0.65 mg/l.Key words: Essential oil, GC-MS, oil composition, antimicrobial activity, Schistostephium hippifolium

Botany: BOT 506

Botany Honours (General Paper): BOT 506, degree examination November 2009

General Paper (Botany Honours): BOT 506

General Paper (Botany Honours): BOT 506, honours degree examination November 2010