The alkaloids of Erythrina abyssinica Seeds

Abstract

In this study the seeds of the plant Erythrina abyssinica, were phytochemically screened and found to contain alkaloids, flavonoids, steroids ,terpenoids,Tannin and saponin. Seven of the alkaloids were isolated and purified by thin-layer chromatography (TLC) on Silica gel using solvent system benzene: Ethanol (9:1), from chloroform extract, Ethyl acetate extract and ethanolic extract. The alkaloids were subjected to spectral studies and the structures were proposed on the basis of its IR, U.V., 1H-NMR and MS spectra which led to the isolation and characterization of five new Erythrina alkaloid.And identified as dihydro-7-methoxyisoboldine, Erythrapharine, methylorientaline, Erythralic acid and demethoxy erythroculine in addition to the known Erythrina alkaloid ,erysodiene and erysotrine. Important physical and chemical properties of the seed oil have been determined: oil content (13%), viscosity (80.5) , saponification value(192) ,iodine value(203),acid value (1.4),ester value (18.9) and unsaponifiable matter (1.9%). The result compared to other oils showed that the Erythina seed oil is a drying oil ,similar to linseed oil. The antimicrobial activity of isolated components was also assessed and the results showed that compound I, IIand III ,displayed moderate activity against Bacillus cereus bacteria and compound I also displayed moderate activity against staphylococcus aureus.