杨梅不同部位单宁含量与结构研究

对杨梅的叶、枝和树皮的总酚含量与可溶缩合单宁含量进行了测定,并利用基质辅助激光解吸附飞行时间质谱(MALDI-TOFMS)详细研究了不同部位中缩合单宁的类型、聚合度及聚合物的分布情况。结果表明:树皮的总酚含量最高(43.56%),叶次之(34.69%),枝最低(18.53%);树叶的可溶缩合单宁含量最高(25.67%),皮次之(17.93%),枝最低(8.01%);3组分的缩合单宁都以(表)棓儿茶素-3-O-棓酸酯(EGCG/GCG)为基本结构单元的原翠雀定,且大部分聚合物的结构单元之间存在A型和B型两种连接方式,但其中叶和枝缩合单宁的聚合度要大于树皮。

Content and Structure of Tannins in Different Parts of Bayberry(Myrica rubra(Lour.)Sieb.et Zucc.)

Contents of total phenolics and extractable condensed tannins in leaves,branches and bark of Myrica rubra(Lour.)Sieb.et Zucc.were determined.In addition,type of condensed tannins,degree of polymerization and distribution of polymer were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS).The results were showed as follows:total phenolics content was the highest in bark(43.56 %),followed by leaves(34.69 %),and then branches(18.53 %);while extractable condensed tannins content was the highest in leaves(25.67 %),followed by bark(17.93 %),and then branches(8.01 %).Epigallocatechin-3-O-gallate was invariably the basic unit occurring in the three condensed tannins.A-type and B-type linkages were the common types among the structural units of polymers.Meanwhile tannins in leaves and branches had the larger highest polymerization degree than bark.