A phytochemical study on the flower of Calotropis gigantea (Linn.) using silica gel column chromatography and preparative thin layer chromatography, led to the first time isolation of Di-(2-ethylhexyl) phthalate (compound 1) and anhydrosophoradiol-3-acetate (compound 2). The structures of these compounds were confirmed by spectroscopic analyses (IR, HRTOFMS and NMR). The antibacterial and antifungal activities of ethyl acetate extract, compound 1 and compound 2 were measured using the disc diffusion method. Ethyl acetate extract and compound 1 presented better results than compound 2. The minimum inhibitory concentrations (MICs) of the extract and compounds were found to be in the range of $16{sim}128{mu}g/ml$. The cytotoxicity ($LC_{50}$) against brine shrimp nauplii (Artemia salina) were also evaluated and found to be 14.61 ${mu}g/ml$ for ethyl acetate, 9.19 ${mu}g/ml$ for compound 1 and 15.55 ${mu}g/ml$ for compound 2.