3alpha-O-Malonyl-12beta-O-acetyl-25-hydroxy-(20S,24R)-epoxydammarane (papyriferic acid) and two previously unknown dammarane triterpenes were identified from diethylether extracts of bark resin from juvenile Betula pendula. H-1 and C-13 NMR spectroscopy showed that a compound appearing often in chromatographic analyses in amounts comparable with papyriferic acid is its 3beta-epimer. The third compound which is abundant in individuals with low levels of the other two compounds was shown to be 3beta-O-malonyl-12beta-O-acetyl-20(S)-hydroxydammar-24-ene (pendulic acid), i.e. an analogue of the 3beta-epimer of papyriferic acid with open and partially reduced C-17 side chain.
|Publication status||Published - 1993|
|MoE publication type||A1 Journal article-refereed|