C18 tetraynoic fatty acids and essential oil composition of Mkilua fragrans.

The fatty acids 17,18-dihydroxyoctadeca-9,11,13,15-tetraynoic acid (mkiluaynoic acid A) and 18-hydroxyoctadeca-9,11,13,15-tetraynoic acid (mkiluaynoic acid B), 5,7,3',4'-tetrahydroxyflavanol, 3,4-dihydroxybenzoic acid and a mixture of stearic and oleic acids were isolated from fruits and stem barks of Mkilua fragrans (Annonaceae). Mkiluaynoic acid A exhibited antifungal activity against Candida albicans comparable with that of the standard antifungal agent Ketoconazole. Structural determination was achieved by analysis of spectroscopic data. The flower stalks yielded essential oils that mainly consisted of sesquiterpenoids as revealed by GC-MS analysis, whereby 14 sesquiterpenes and four other compounds were identified.