A chemical examination of the polyphenolic constituents of the fern, Dicranopteris pedata HOUTT., has led to the isolation of eight new proanthocyanidins possessing a doubly-linked (A-type) unit, together with known flavan-3-ols and proanthocyanidins. On the basis of chemical and spectroscopic evidence, they are characterized as epiafzelechin-(4β→8, 2β→O→7)-eniafzelechin-(4α→8)-epiafzelechin(8), epicatechin-(4β→8, 2β→O→7)-epiafzelechin-(4α→8)-epiafzelechin(9), epiafzelechin-(4β→8, 2β→O→7)-epizfzelechin-(4α→8)-epicatechin(10), epiafzelechin-(4β→8, 2β→O→7)-epicatechin-(4α→8)-epicatechin (11), epicatechin-(4β→8, 2β→O→7)-epiafzelechin-(4α→8)-epicatechin (12), epicatechin-(4β→8, 2β→O→7)-epicatechin-(4α→8)-epiafzelechin (13), epicatechin-(4β→8, 2β→O→7)-epicatechin-(4α→8)-epigallocatechin (14) and epiafzelechin-(4β→8)epicatechin-(4β→8, 2β→O→β→7)-epicatechin-(4α→8)-epicatechin (15).
通过对蕨类植物 Dicranopteris pedata HOU
TT.的多
酚类成分进行
化学研究,分离出了 8 种新的
原花青素,它们与已知的黄烷-3-醇和
原花青素都具有双链(A 型)单元。根据
化学和光谱证据,它们的特征是
表儿茶素-(4β→8, 2β→O→7)-epeniafzelechin-(4α→8)-epiafzelechin(8),
表儿茶素-(4β→8、2β→O→7)-epiafzelechin-(4α→8)-epiafzelechin(9), epiafzelechin-(4β→8, 2β→O→7)-epizfzelechin-(4α→8)-epicatechin(10), epiafzelechin-(4β→8, 2β→O→7)-epicatechin-(4α→8)-epicatechin (11)、
表儿茶素-(4β→8, 2β→O→7)-epiafzelechin-(4α→8)-epicatechin (12)、
表儿茶素-(4β→8, 2β→O→7)-epicatechin-(4α→8)-epiafzelechin (13)、
表儿茶素-(4β→8、2β→O→7)-epicatechin-(4α→8)-epigallocatechin (14) 和 epiafzelechin-(4β→8)epicatechin-(4β→8, 2β→O→β→7)-epicatechin-(4α→8)-epicatechin (15)。