Antim ycob acterial alkaloids, fatty acid and extracts of monodora carolinae and m Hastipetala

This dissertation reports on the isolation, structure determination of alkaloids and fatty acid from Monodora carolinae and their in vitro antimycobacterial activity against Mycobacterium madagascariense (MM) and M. indicus pranii (M1P). It also reports the toxicity against brine shrimp (Artemia salina) larvae and chemical profiling of extracts of M. carolinae and M. hastipetala. The chemical profiling using TLC indicated both species to contain similar constituents. The crude extracts of the two plants species exhibited antimycobacterial activity with MIC values ranging from 4 to 10 mg/mL and brine shrimp toxicity with LC50 values ranging from 3 to 189 |ig/mL. Phytochemical investigations of antimycobacterially active dichlomethane extract of the stem bark of M. carolinae yielded 4-(l//-indol-6-yl)- but-3-en-2-one (68), 5-formylindole (71) and (Z)-hexadec-8-enoic acid (79), while ethanol extract of the stem bark of M. carolinae yielded an arylnaphthalene lignanamide cannabisin B (82). The structures of the isolated compounds were determined by using NMR spectroscopic data. When evaluated for their antimycobacterial activity, compounds 71 and 79 exhibited significant activity with MIC value of 1.25 and 2.50 mg/mL against MM, respectively, compound 68 exhibited activity against MIP with MIC value of 2.50 mg/mL while compound 82 was inactive to MM at the tested concentration of 5 mg/mL. Isolation of prenylated indole derivative from M. carolinae is of chemotaxonomic significance as the results further affirm taxonomic placement of this newly described plant species into the genus Monodora. Isolation of cannabisin B from this study further indicates chemodiversity of natural products elaborated by rare Tanzanian Annonaceous plant species.