One new and several minor diarylheptanoids from Amomum muricarpum

A new natural diarylheptanoid, designated muricarpin, together with four diarylheptanoids were isolated from the rhizomes of Amomum muricarpum Elmer (Zingiberaceae) growing in Vietnam. Three known compounds, 1,7-bis(3,4-dihydroxyphenyl)heptan-3-yl acetate, 1-(4'-hydroxyphenyl)-7-(3 '',4 ''-dihydroxyphenyl)heptan-3-yl acetate and 1-(3',4'-dihydroxyphenyl)-7-(4 ''-hydroxyphenyl)-heptan-3-one were isolated for the first time from the genus Amomum, meanwhile (5R)-5-hydroxy-1,7-bis(4-hydroxyphenyl)-heptan-3-one was found for the first time in plants. Their structures were determined using spectroscopic analyses.