[Flavonoids from the seeds of Alpinia galanga Willd].

Ten flavonoids were isolated from the 95% ethanol extract of the seeds of Alpinia galanga Willd. with a combination of various chromatographic techniques, including silica gel, Sephadex LH-20 and preparative HPLC. On the basis of spectroscopic data analysis, they were elucidated as (2R, 3S)-pinobaksin-3-cinnamate (1), (2R, 3R)-pinobaksin-3-cinnamate (2), pinocembrin (3), pinobaksin (4), 3-O-acetylpinobaksin (5), galangin (6), galangin-3-methylether (7), kumatakenin (8), 3-methylkaempferol (9) and (2R, 3R)-3, 5-dihydroxy-7-methoxyflavanone (10).

Three new norsesquiterpenoids from the seeds of Alpinia galanga.

From the seeds of Alpinia galanga Willd., three new norsesquiterpenoid racemic mixtures, galanols A-C (1-3) were isolated, along with three known sesquiterpenoids (4-6). Their structures were elucidated by means of UV, IR, HR-ESI-MS, 1D NMR and 2D NMR spectroscopic data.