| Extracts of the bark of Pavetta owariensis (Rubiaceae) were found to exhibit schistosomicidal, molluscicidal, antiviral and antibacterial activities. Bio-assay guided fractionation resulted in the isolation of new antimicrobially active proanthocyanidins with doubly-linked structures. In a chemical investigation on the stem-bark, 3 flavan-3-ol, 4 procyanidin-A-type, 6 trimeric procyanidins, 4 tetrameric procyanidins, 1 pentameric procyanidin (all possessing doubly-linked structures), 15 fatty acids, 19 fatty alcohols, 11 fatty esters, 8 alkanes, 4 sterols, 7 ketosteroids, 5 quinic acid esters, and 5 ferulic esters were characterized.; The crude alkaloids from the aerial parts of Borreria verticillata (Rubiaceae) has shown to exhibit antibacterial and cytotoxicity properties. Bio-assay guided fractionation led to the isolation of three antibacterial active bis-indole alkaloids, along with 5 other alkaloids.; Extracts of Harrisonia abyssinica (Simaroubaceae) were found to exhibit molluscicidal, antibacterial, antiviral and antifungal properties. Bio-assay guided fractionation resulted in the isolation of the active components which are under current investigation. Chemical investigations on the stem-bark and the root led to the isolation of 2 sterols, 3 ketosteroids, 2 chromones, 3 limonoids.; The schistosomicidal effect of Pavetta owarienis along with the molluscicidal potency of Harrisonia abyssinica may be considered as a possible alternative in a schistosomiasis control program in affected areas such as the South part of Guinea-Conakry, where these plants are available. |
