Abstract:To understand the chemical constituents of Alpinia hainanensis ‘Shengzhen’, ten flavonoids were isolated from its stems by chromatographic techniques. On the basis of spectral data, they were identified as (-)-pinocembrin (1), (±)-alpinetin (2), (±)-7,4'-dihydroxy-5-methoxy-dihydroflavonol (3), uvangoletin (4), cardamonin (5), helichrysetin (6), (+)-catechin (7), (-)-epicatechin (8), proanthocyanidin A1 (9), and proanthocyanidin A6 (10). The compounds 1, 3, 5, 7-10 exhibited remarkable ABTS radical scavenging activities and compounds 7-10 displayed significant DPPH radical scavenging activities.