Chemical Evaluation of Betula Species in Japan. II. Constituents of Betula platyphylla var. japonica

抄録

The constituents of Betula platyphylla var. japonica were identified as follows : Fresh leaves : 12-O-acetyl-3-O-malonylbetulafolienetriol, 12-O-acetyl-3-O-malonylbetulafolienetriol oxide I (=papyriferic acid), 12-O-acetyl-betulafolienediolone, hydroxyhopanone, caryophyllene oxide, kaempferol 3-O-(4-O-acetyl)-α-L-rhamnopyran-oside, quercetin 3-O-(4-O-acetyl)-α-L-rhamnopyranoside. Outer bark : betulin, lupeol, betulinic acid, betulone, betulin 3-O-caffeate, oleanolic acid, oleanolic acid 3-O-acetate. Inner bark : (-)-catechin, (-)-catechin 7-O-β-D-xylopyranoside, rhododendrin (=betuloside), aceroside VII, aceroside VIII, 1, 7-bis[4-hydroxyphenyl]-3-hepten-5-one, 2-hydroxy-1, 7-bis[4-hydroxyphenyl]-3-hepten-5-one, acerogenin E, (3R)-3, 5'-dihydroxy-4'-methoxy-3', 4"-oxo-1, 7-diphenyl-1-heptene, 7α-hydroxy-β-sitosterol, 7β-hydroxy-β-sitosterol. Root bark : dammarenediol II 3-O-p-coumarate, dammarenediol II 3-O-caffeate, ocotillol II 3-O-caffeate, stigmast-4-ene-3-one. Spikes : caryo-phyllene oxide, (-)-rhododendrol (=betuligenol), 12-O-acetylbetulafolienetriol. The compounds with an asterisk are new.