Butea monosperma (LAM.) TAUB. (Fabaceae), known in Thai as Tong-kwoaw, is a medium sized deciduous tree of up to 50 feet high with stunning flower clusters, very conspicuous when in flower, and the trunk is usually crooked and twisted with irregular branches and rough, grey bark. The flowers are bright orange red, large and in rigid racemes.
1)This plant species has been found to display a wide variety of biological activities. The stem bark is used in indigenous medicine for the treatment of dyspepsia, diarrhea, dysentery, diabetes, ulcers, sore throat and snake bites.2) The flower extract showed antidiabetic effect in rats.3) The plant leaves exhibited antiinflammatory effect 4) and exerted effect on stress, anxiety and cognition in rats.5) Anti-diarrhoeal activity of the ethanolic extract of the stem bark 6) and anticonvulsive activity of the petroleum ether extract of the flowers 7) of this plant species in experimental animals have been reported. The plant extracts exhibited other biological activities including aphrodisiac activity in male rats, 8) anthelmintic activity, 9,10) and dermal wound healing in rats. 11) Isolation of (Ϫ)-medicarpin with antifungal activity from this part of the plant has also been reported. 12) From the flowers of this plant species the flavonoids butin (1), butein (2), butrin (3), isobutrin, palasitrin, coreopsin, isocoreopsin, sulphuresin, monospermoside (4), isomonospermoside (5) and 7,3Ј,4Ј-trihydroxyflavone (6) have been isolated. [13][14][15] Antihepatotoxic activity of the flower extract 16) and of compound 3 and isobutrin 17) has been observed. Compound 1 which was isolated from the seeds of this plant species showed estrogenic and postcoital anti-conceptive activity in rats.18) A lectin was also isolated from the seeds and was found to agglutinate human erythrocytes. The activity was inhibited by N-acetyl galactosamine and did not require a divalent ion.19) The euphane triterpenoid 3a-hydroxyeuph-25-ene and the alcohol 2,14-dihydroxy-11,12-dimethyl-8-oxo-octadec-11-enylcyclohexane have been isolated from the stem.20) The imide palasimide has been isolated from the pods of this plant species.21) Stigmasterol, stigmasterol-3-O-b-D-glucopyranoside and nonacosanoic acid were also among those isolated compounds. 15,20) As part of an ongoing project on bioactive compounds from Thai medicinal plants for the treatments of tropical diseases, the plant species was investigated and it was found that the EtOAc and MeOH extracts exhibited antimycobacterial activity. The present report deals with the One new dihydrochalcone, dihydromonospermoside (7), was isolated from the flowers of Butea monosperma together with three known chalcones, butein (2), monospermoside (4) and isoliquiritigenin (8), one flavone, 7,3 ,4 -trihydroxyflavone (6), four flavanones, (؊)-butin (1a), (؊)-butrin (3a), (؉)-isomonospermoside (5b) and (؊)-liquiritigenin (9a), and three isoflavones, formononetin (10), afrormosin (11) and formononetin-7-O-b b-D-glucopyranoside (12). The structure of the new compound was e...
