Sterols and flavone from the leaves of vernonia amygdalina growing in Thua Thien Hue

Abstract

By using various chromatographic methods, two sterols and one flavones (22R,23S,24R,28S)-28-methoxy-7,8,9,11-tetradehydro-3β, 16α,21,24-tetrahydroxy-21,23 :22,28-diepoxy-5α-stigmastane (1), (23S,24R,28S)-3β,22α-dihydroxy-7,8,9,11-tetradehy dro-24,28-epoxy-5α-stigmastane-21,23-carbolactone (2), and luteolin (3) were isolated from the methanol extract of the leaves of Vernonia amygdalina. Their structures were determined using 1D, 2D – NMR and ESI-MS analysis as well as by comparison with the reported data. Compound 1 and 2 were reported from nature for the first time.