摘要：

The constituents of Betula schmidtii REGAL Were identified as follows. Fresh leaves: methyl (12R,20S)-20-hydroxy-12-beta-D-xylopyranosyloxy-3,4-secodammara-4(28),24 -dien-3-oate (betula-schmidtoside A)*, myricetin 3-O-alpha-L-arabinofuranoside, myricetin 3-O-alpha-L-rhamnopyranoside, myricetin 3O-beta-D-galactopyranoside, (-)-rhododendrol 4'-O-beta-D-glucopyranoside*. Outer bark: betulin, lupeol, oleanolic acid, betulone, betulonic acid. Inner bark: (+)-catechin, (3R)-3,5'-dihydroxy-4'-methoxy-3',4 "-oxo-1,7-diphenyl-1-heptene, (-)-lyoniresinol 3 alpha-O-beta-D-xylopyranoside, (+)-lyoniresinol 3 alpha-O-beta-D-glucopyranoside, monogynol A, ssioriside, (-)-rhododendrol 4'-O-beta-D-glucopyranoside*, (-)-rhododendrol 4'-O-alpha-L-arabinofuranosyl-(1-->6)-beta-D-glucopyranoside*. Root bark: oleanolic acid 3-caffeate, 27-hydroxyoleanolic acid 27-caffeate. The three compounds with asterisks are new.

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