BIOLOGICALLY-ACTIVE FLAVONOIDS AND KAVA PYRONES FROM THE AQUEOUS EXTRACT OF ALPINIA ZERUMBET

From the aqueous extract of Alpinia zerumbet (Pers) Lf, L, Burttet Smi th. (= Alpinia speciosa K, Schum,) flavonoids and kava pyrones were ob tained, The flavonoids identified as rutin (1), kaempferol-3-O-rutinos ide (2), kaempferol-3-O-glucuronide (3), (+)-catechin (4) and (-)-epic atechin (5) are well known substances that can contribute to the hypot ensive, diuretic and antiulcerogenic activity of the aqueous extract o f the plant, while the kava pyrones dihydro-5,6-dehydrokawain (6) and 5,6-dehydrokawain (7) have been described as antiulcerogenic and antit hrombotic, The compounds were identified from their UV, H-1- and/or C- 13-NMR, hydrolytic and co-TLC data. The well known activity of these c ompounds, which have not been previously isolated from the leaves of A lpinia zerumbet, may explain the use of the plant in the treatment of hypertension. (C), 1998 John Wiley & Sons, Ltd.