Chemical Constituents and Phytotoxicity of Solvent Extracted Fractions of Stem Bark of Grewia optiva Drummond ex Burret

Studies on the chemical constituents of the stem bark of Grewia optiva have led to the isolation of four triterpenes; betulin (1), betulinic acid (2), oleanolic acid (3), ursolic acid (4) one sterol; daucosterol (5). The structures of these compounds have been elucidated through spectral studies including 1D and 2D-NMR experiments (HMQC, HMBC, COSY, NOESY and J-resolved) and EI and HRMS. They were isolated for the first time from this genus. Crude ethanolic extract of the stem bark of Grewia optiva were tested for their in Vitro Phototoxic Bioassay against Lemna minor plant. This paper is based on the isolation, characterization of chemical constituents as well as Phytotoxicity of crude extract and different solvent extracted fractions.