Methanolic extract of the leaves of Bridelia stipularis was studied. From this study, we isolated three known flavonoids. They were identified as 7-O-methyl luteolin, apigenin and 5, 7, 2', 5' tetrahydroxyflavone by NMR spectroscopic studies. All of them are first time documented for this plant. Different solvent fractions were subjected to in vitro antioxidant and cytotoxicity studies. Both apigenin and ethyl acetate soluble fraction of Bridelia stipularis showed strong antioxidant activity having IC 50 value of 8.005, 8.77 µg/mL respectively. Chloroform soluble fraction of Bridelia stipularis exerted the highest toxicity to brine shrimp and petroleum ether soluble fraction showed moderate toxicity having LC 50 value of 1.05, 1.71 µg/mL respectively.

The stem bark of Baccaurea ramiflora was studied. Four aldehydes named as 3 methoxy 4 hydroxy-cinnamaldehyde (coniferyl aldehyde); 3, 4, 5 trimethoxy cinnamaldehyde; 3, 4, 5 trimethoxy benzaldehyde and 3,4 dimethoxy benzaldehyde) (veratraldehyde) have been isolated and then identified by NMR spectroscopy. All of them are first time reported for this plant. Here in vitro biological investigations include antioxidant and cytotoxicity study. Among all fractions, the chloroform soluble fraction exhibited strong free radical scavenging activity having IC 50 value of 12.87 µg/ml compared to BHT (IC 50 value 5.64 µg/ml). On the contrary, aqueous soluble fraction exhibited most toxicity towards brine shrimp compared with vincristine sulphate having LC 50 value of 1.44 and 0.9258 μg/ml respectively.