摘要
从窿缘桉(Eucalyptus exserta F.Muell.)树叶中分离并鉴定了桔酸、(+)-儿茶素和杨梅酮葡萄糖甙化合物,及以乙酰衍生物形式分离出二种黄烷-3-醇的二聚体 B_1和 B_3,并进行了鉴定。通过水解、花色素、间苯三酚降解反应以及旋光、紫外光谱、高效液相色谱、红外光谱、C核磁共振等研究,确定缩合类单宁部份是原花青定(少量原翠雀定),其终端单元由(+)-儿茶素构成,延伸单元是(-)-表儿茶素,联结方式是 C_4-C_8联结,黄烷-3-醇的平均聚合度为4—5。
The gallic acid,(+)-catechin and myricetin glucoside have been isolated and indentified from Bendo Eucalyptus,and two kinds of dimeric flavan-3-ol B_1 and B_3 were isolated as their peracetates and identified by chromatography on TLC and^1H NMR spectroscopic cha- racteristics.It is showed that condensed tannin is a procyanidin with(+)-catechin as termi- nal units and(-)-epicatechin as extension units by hydrolyzation anthocyanidin reaction, phloroglucinol degradation and polarimetry,UV and IR spectrometry,HPLC,^(13)C NMR. Linkage is C_4-C_8.Degree of polymerization is about 4—5.
关键词
分离
鉴定
桉树叶
单宁
组分
Bendo Eucalyptus
procyanidin
cyanidin
flavan-3-ol
condensed tannin
hydrolyzable tannin
