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)-epoxy-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, betulafolienetetraol, 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-p-coumarate*, oleanolic acid 3-O-caffeate. The six compounds with asterisks are new.