Correlation between chemical composition and antimicrobial activity. VI. Activity of some African essential oils

The composition of thirteen essential oils of African origin (mostly Cameroon) were examined by GC and GC/MS. Oils of Xylopia aethiopica A. Rich.(Fruits), X. parviflora (A. Rich) Benth. (Fruits), Monodora myristica (Gaertn) Dunal (Fruits), M. brevipes Benth. (Seeds), Annona senegalensis Pers. (Fruits), Cananga odorata Hook. f. et Thomson (Fruits, Leaves), Tagetes minuta L. (Leaves, Flowers), Hernandia voyroni R. Cap. (Bark), Ageratum conyzoides L. (Leaves), Cymbopogon citratus (DC) Stapf (Leaves) and Aframomum citratum Pereira ex Oliv. et Hanb.) (Seeds) were included in this study. The major components of the oils were X. aethiopica: alpha-pinene (17.4%), sabinene (23.9%) and terpinen-4-ol (12.9%); X. parviflora: alpha-pinene (14.0%) and beta-pinene (40.0%); M. myristica: alpha-phellandrene (48.8%) and alpha-pinene (15.9%); M. brevipes: alpha-phellandrene (74.9%), A. senegalensis; alpha-phellandrene (24.9%), alpha-pinene (11.9%) and myrcene (11.3%); C. odorata Fruits: alpha-pinene (11.1%), myrcene (24.7%) and sabinene (34.3%); C. odorata Leaves: alpha-pinene (14.0%), beta-caryophyllene (26.3%) and germacrene D (11.7%); T. minuta Leaves: (E)-tagetenone (16.9%), (Z)-tagetenone (16.8%) and (Z)-tagetone (11.6%); T. minuta Flowers: (Z)-beta-ocimene (31.8%) and (Z)-tagetone (46.0%); H. voyroni: perillaldehyde (82.8%); A. conyzoides: beta-caryophyllene (10.5%) and precocene I (81.0%); C. citratus: myrcene (12.8%), geranial (45.9%) and neral (33.5%) and A. citratum: geraniol (68.9%) and linalool (15.1%). These compositions were correlated with the antimicrobial activities of the oils towards six microbial strains (Staphylococcus aureus, Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans). Oils of Cymbopogon citratus, Hernandia voyroni and Aframomum citratum displayed noteworthy antibacterial and antifungal activities.