140 Saudi Pharmaceutical Journal, Vol. 15, No.2, April 2007 PHYTOCHEMICAL AND BIOLOGICAL INVESTIGATIONS OF ERYTHRINA VARIEGATA Mohammed Z. Rahman 1 , Shirin J. Sultana 2 , Chowdhury F. Faruquee 3 , Faisol Ferdous 3 , Mohammad S. Rahman 3 , Mohammad S. Islam 2 and Mohammad A. Rashid 3,4,* Five compounds were isolated from the n-hexane and chloroform soluble fractions of a methanol extract of the stem bark of Erythrina variegata. The structures of the isolated compounds were elucidated as alpinum isoflavone (1), epilupeol (2), 6-hydroxygenistein (3), 3β, 28- dihydroxyolean-12-ene (4) and stigmasterol (5) by extensive spectroscopic studies, including high field NMR analyses. Different partitionates of the methanol extract exhibited mild to moderate antimicrobial activity and varying degrees of cytotoxicity. Although, alpinum isoflavone (1) has previously been reported from E. variegata, this is the first report of isolation of compounds 2-4 and stigmasterol from this plant species. Key words: Erythrina variegata, Fabaceae, alpinum isoflavone, 6-hydroxygenistein, 3β, 28- dihydroxyolean-12-ene, epilupeol, stigmasterol. Introduction Erythrina variegata (Bengali name- Mandar; Family, Fabaceae) is a medium-sized deciduous small tree with prickly stems and branches, leaves with triangular leaflets and large coral red flowers and grows all over Bangladesh. The bark of the plant is astringent, febrifuge, anti-bilious and anthelmentic. It is also useful in optha- lmia and skin diseases. The leaves are used in fever, inflammation and joint pain. The juice of the leaves is used to relieve earache and toothache (1). It has the reputation to stimulate lactation and menstruation and is used as laxative, diuretic and expectorant (2). Although many compounds have been reported from the genus, Erythrina, previous phytochemical investigations with E. variegata revealed the occurrences of orientanol B, erycrista- gallin, cristacarpin, sigmoidin K, 2-(γ,γ-dimethy- lallyl)-6a-hydroxyphaseollidin, erystagallin A (3), eryvarins A and B (4), bidwillon B (5), eryvarinol A and B (6), eryvarins F and G (7), alpinum isofla- vone, isococculinine, decarbomethoxyerymelanth- ine, erysodienone, erythritol, erysodine (8), eryso- vine, stachydrine, sterols, fixed oils and fatty acids (9). We, herein, report the isolation of alpinum isoflavone (1), 6-hydroxygenistein (2), 3β,28-dihy- droxyolean-12-ene (3), epilupeol (4) and stigma- sterol (5) from a methanol extract of E. variegata. אאאא – א א K אאאאא ) 1 ( ) 2 ( ، 6 - ) 3 ( ، و3 - 28 - א - 12 - إ F 4 E א، F 5 E אא K אאא אK א אאא א K ) 1 ( ، א4-2 אאא K 1 Department of Pharmacy, The University of Asia Pacific, Dhaka-1209, Bangladesh 2 Department of Clinical Pharmacy and Pharmacology, Faculty of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh. 3 Phytochemical Research Laboratory, Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Dhaka, Dhaka-1000, Bangladesh. 4 Centre for Biomedical Research, University of Dhaka, Dhaka-1000, Bangladesh. * To whom correspondence should be addressed. E-mail: rashidma@aitlbd.net