(2S)-Prenylflavanones and taraxerane triterpenoids from Mallotus mollissimus

Abstract Three prenylflavanones, (2 S )-5,7-dihydroxy-4′-methoxy-8-(3″,3″-dimethylallyl)flavanone ( 3 ), (2 S )-5,4′-dihydroxy-7-methoxy-6-(3″,3″-dimethylallyl)flavanone ( 6 ), 8-prenylnaringenin ( 11 ), and a new epimeric pair (2″ S /2″ R )-(2 S )-5,7-dihydroxy-4′-methoxy-6-(2″-hydroxy-3″-methylbut-3″-enyl)flavanones ( 4a/4b ) were isolated together with taraxerone, taraxerol, epitaraxerol, β -sitosterol, oleanolic acid, 1- O -docosanoyl glycerol, apigenin, and apigenin 7- O - β -D-glucopyranoside from the MeOH extract of the leaves of Mallotus mollissimus . The structures of the isolated compounds were determined on the basis of 1D/2D NMR and HR-MS spectroscopic data; the 2 S configuration of the prenylflavanones 3 , 4 , and 6 was deduced from CD spectroscopic data. The presence of three taraxerane triterpenoids reinforces the inclusion of M. mollissimus ( syn. Croton mollissimus ) in Mallotus genus. Among species of Mallotus the occurrence of the (2 S )-prenylflavanones 3 , 4 , and 6 is confined to M. mollissimus .