白桦树皮化学组成的研究

经究了白桦树皮的化学组成，内皮的外皮的灰分、抽提物、木质素、多戊糖、综纤维素和软木脂含量。通过ＧＣ、ＧＣ－ＭＳ对外皮中的两种主要成分软木脂单体和三萜系化合物进行了定性和定量分析。不同径级的三个样品的软木脂脂单体平均含量每公斤外皮（干基，下同）为１７５ｇ，软木脂单体中以９，１０－环氧－１８－羟基十八烷酸为主，每公斤外皮为５５．１ｇ，占软木脂单体总量的３１．５％。可确认的软木脂单体占气相色谱可分谱可分

THE CHEMICAL COMPOSITION OF THE BIRCH BARK

The chemical composition of the bark from the Betula platyphylla sukat was studied.The contents of the ash,extracts,lignin,pentosans,holocellulose and suberin in inner and outer bark were determined respectively.The suberin monomers and triterpenoide,the two major component in the outer bark of birch were analysed qualitatively and quantitatively by GC and GC-MS.The average content of suberin monomers from 3 different diameter bark samples was 175g/kgof the dry outer bark.The principal suberin monomer was 9,10-epoxy-18-hydroxyoctadecanoic acid(55.1 g/kg of dry bark and 31.5% of the suberin monomers).The identified monomer covered 90.2% of the components detectable by GC analysis.The triterpenoids from the same bark samples was 434.4g per kg dry bark.The predominant triterpenoids was betulinol(423.2g/kg dry bark).Lupeol was next(11.2g/kg). Diametral fluctuations in the amount and composition of suberin monomers and triterpenoide in the outer bark of birch are not apparent.