Separation and bioactivity of diarylheptanoids from lesser galangal (Alpinia officinarum)

Diarylheptanoids from the rhizomes of Alpinia officinarum were isolated by column chromatography and HPLC. Normal phase column chromatography followed by semi-preparative reversed-phase HPLC was used to isolate five diarylheptanoids, which were identified as 5-hydroxy-7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-3-heptanone (AO-1), 5-methoxy-7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-3-heptanone (AO-2), 7-(4"-hydroxyphenyl)-1-phenylhept-4-en-3-one (AO-3), 7-(4"-hydroxy-3"-methoxyphenyl)-1-phenylhept-4-en-3-one (AO-4), 1,7-diphenylhept-4-en-3-one (AO-5). This paper discusses the separation and isolation of these compounds and their biological as well as antioxidant activity.