Synonyms: 2-Cyclopenten-1-one,3,4-dihydroxy-2-isovaleryl-5-(3-methyl-2-butenyl)-, trans-(+)- (8CI);2-Cyclopenten-1-one,3,4-dihydroxy-5-(3-methyl-2-butenyl)-2-(3-methyl-1-oxobutyl)-, (4R,5R)- (9CI);2-Cyclopenten-1-one,3,4-dihydroxy-5-(3-methyl-2-butenyl)-2-(3-methyl-1-oxobutyl)-, (4R-trans)-;Humulinic acid A (7CI)