Chemical Evaluation of Betula Species in Japan. III. Constituents of Betula maximowicziana.

Abstract

The constituents of Betula maximowicziana REGAL in Japan were identified as follows. Fresh leaves : 12β-acetoxy-20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane, 20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane, 3-epi-ocotillol II, 12β-acetoxy-20(S), 24(R)-epoxy-3α, 25-dihydroxydammarane, 12β-acetoxy-20(S), 24(R)-epxy-3α, 17α, 25-trihydroxydammarane 3-O-β-D-glucopyranoside (betulamaximoside A)*, 12β-acetoxy-20(S), 24(R)-epoxy-3α, 17α, 25-trihydroxydammarane 3-O-β-D-(6-O-acetyl)-glucopyranoside (betulamaximoside B)*, 12-O-acetyl-betulafolienetetraol, betulafolieneteraol, 6-methoxykaempferol, 6-methoxy-3-O-methylkaempferol and naringenin. Outer bark : betulin, betulin 3-O-caffeate, lupeol, lupane-3β, 20, 28-triol, lupane-3β, 20, 28-triol 3-O-caffeate, acetyl-oleanolic acid. Inner bark : acerogenin E, 16-hydroxy-17-O-methylacerogenin E*, alnusdiol β-D-glucopyranoside*, lyoniresinol 3α-O-α-L-rhamnopyranoside, 3, 4, 5-trimethoxyphenol β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside, benzyl alcohol β-D-apiofuranosyl-(1→6)-β-D-glucopyranoside, (+)-catechin 7-O-β-D-xylopyranoside and monogynol A. Root bark : dammarenediol II 3-O-caffeate, dammar-24-ene-3β, 20(S), 26-triol 3-O-caffeate*, dammar-24-ene-3β, 20(S), 26-triol 3-O-coumarate*, oleanolic acid 3-O-caffeate. The six compounds with asterisks are new.