Phytochemical and biological investigation on Ipomoea pescaprae(L.)R.Br.

A total of five compounds eicosanyl-trans-p-coumarate (1), stigmasterol(2), β-sitosterol (3), β-amyrin(4), 6-hydroxy stigmasta-4,22-dien-3-one (5) were isolated from the methanolic extract of the stem bark of Ipomoea pescaprae(L.) R.Br.(Family:Convolvulaceae). The petroleum ether, carbon tetrachloride; chloroform and aqueous soluble Kupchan fractions of crude methanol extract were studied for antioxidant, antimicrobial and cytotoxic activities. Among the different fractions tested for antioxidant activity, the aqueous soluble partitionate was the most potent with IC50 value of 7.50μg/ml as compared to tertbutyl-1-hydroxytoluene (IC50=20.96μg/ml). Antimicrobial screening of the different extractives was conducted by the disc diffusion method and the crude methanol extract as well as aqueous soluble fractions exhibited moderate antimicrobial activity with zone of inhibition ranging from 10-12 mm. In brine shrimp lethality bioassay, the aqueous soluble materials demonstrated the highest toxicity with LC50 of 1.01μg/ml. Compounds eicosanyl-trans-p-coumarate, stigmasterol, β-sitosterol, 6-hydroxy stigmasta-4,22-dien-3-one are the first report of isolation of compounds from Ipomoea pescaprae. Key words: Ipomoea pescaprae, chemical constituents, antioxidant, antimicrobial, cytotoxicity.