Steam-distilled volatile oil from Artemisia ajira Jacq. (family Compositae), indigenous to the mountainous regions in southern Africa and used in popular medicine, was analysed by gas chromatography and tested for antimicrobial and antioxidative properties. The main components of the volatile oil were a-and /I-thujone (52%), 1,8-cineole (13 "/,), camphor (15 %) and a-pinene (2 %). Twenty-five bacterial species and three filamentous fungi were used to assess the antimicrobial properties. Fifteen test bacteria and one fungus showed high degree of inhibition of growth caused by the volatile oil. The most susceptible organisms were Acinetobacter calcoaceficus, Beneckea nafriegens, Breuibacferium linens, Brochothrix fhermosphacta, Citrobacter jiieundii, Klebsiella pneumoniae and Serratia marcescens. The oil exerted considerable antioxidative effect.

Abstract:The essential oil obtained from Heteropyxis natalensis by steam distillation was tested for antimicrobial properties. Twenty five bacterial and four fungal species were used as test organisms in this study. These included animal and plant pathogens, food poisoning bacteria and mycotoxigenic fungal strains. The essential oil exhibited considerable inhibitory activities against all the test organisms. GC-MS analysis indicated the essential oil contained 1,8-cineole, limonene, /?-myrcene, a-phellandrene and a-pinene.

The essential oil from the leaves of Clausena anisam (Willd.) J.D. Hook ex Benth. was isolated by hydrodistillation. The oil was analysed by a combination of GC and GC-MS The oil contained mainly sabinene (33.0%). germacrene-D (17.0%) 2-p-ocimene (6.0%). germacrene-B (5 5%), (E)-P-ocimene (4.9'10) and terpinen-4-01 (4.7% ). Using the hole-plate diffusion method for antibacterial testing. the volatile oil exhibited significant activity against Benec-kea noirtegrns. Flui,obac-ieriitrn ~u o i * e o l m s , Enrerococcits faecalis. Baci1lic.s stchiilrs. Serratia marcesccns. Alcaligenes faec-aliJand Lcuconosioc crernoris. The mycelium growth inhibition method was used to test for antifungal activity. The fungal species Grotrichuni candidttm. Asprrgtlliu parcisiticiu. Candida alhtcms. Pentcillrurn c-tirtnurn and Alrcrrioriu alrcrnaia shoued significant sensitivity to the volatile oil.

A hydrodistilled oil obtained from the leaves of Leucas milanjiana Gurke (Lamiaceae) was analysed by capillary GC and GC-MS. The leaf volatile oil contained 30 components, out of which 26 were identified. The predominant components were found to be β β β β β-cubebene (38.15%), α α α α α-pinene (19.71%), trans-caryophyllene (7.41%) and α α α α α-terpinolene (5.34%). The results are qualitatively and quantitatively at variance with data on other Leucas species and may therefore be of some chemotaxonomic significance for the genus.

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