Study of Some Chemical Constituents and Antioxidant Activity of Beaumontia grandiflora Wall. grown in Egypt

Beaumontia grandiflora Wall. (Apocynaceae) is an ornamental plant cultivated in Egypt. Investigation of the chemical constituents of the aerial parts of B. grandiflora Wall. in pet. ether extract led to isolation and identification of twelve fatty acids in which linoleic acid (29.60%) and Palmitic acid (19.12%) are the main acids. The unsaponifiable fraction was found to contain a series of hydrocarbons (n-C14 - n-C27) in addition to P-sitosterol, stigmasterol, cholesterol, campasterol and a-amyrine.The flavonoidal constituents were isolated from the ethyl acetate fraction of the alcoholic extract. Four flavonoids were identified as; quercetin i, quercetin-3-O-galactoside ii, diosmetin-7-O-rhamnoside iii and kaempferol-3-O-neohesperidoside iv. The crude extracts (total alcoholic, ethyl acetate, and butanol extracts) and the isolated compounds were screened for their antioxidant activity using DPPH radical Scavenging method. Ethyl acetate extract and compound 1 showed high antioxidant activity compared to Trolox (standard antioxidant compound) 91, 89% respectively