中文摘要：

无瓣海桑（Sonneratia apetala）作为红树植物外来种，引种到我国后得到大面积种植．本文以广东湛江高桥无瓣海桑林为研究对象，分析了不同部位的单宁含量，并利用MALDI-TOFMS对成熟叶片纯化单宁的化学结构进行分析．研究结果表明：（1）无瓣海桑不同部位（叶片、树皮、根、果）总酚含量在（127．73±3．80）-（359．54±63．28）mg／g之间，其中树皮的总酚含量最高，而花的含量最低，叶的总酚含量也较高，在不同发育阶段叶片中差异不显著,可溶性缩合单宁在花中的含量也最低（（17．56±2．61）mg／g），但在果和树皮中最高（（276．48±9．62）mg／g和（254．71±5．62）mg／g）．蛋白质结合能力在叶片和果较高，而在根中最低．（2）经MALDI-TOF质谱分析显示，无瓣海桑成熟叶片纯化单宁是以葡萄糖分子和桔酰基为基本结构单元的水解单宁，其中桔酰基通过与葡萄糖或另一份子桔酰基脱水形成的共价键相连．

英文摘要：

Sonneratia apetala is an alien mangrove species. It has been widely planted in tropical and subtropical coastlines of China. Tannins levels in different parts of S. apetala were determined,chemlcal structure of purified tannins from mature leaves was analyzed by MALDI-TOF MS. The results showed as follows： 1. Total phenolics contents in the different parts of S. apetala varied from （ 127.73 ±3.80） mg/g to （359.54 ±63.28 ） mg/g,with the lowest of flowers and the highest in bark; no significant difference was found at the developmental stages of leaves. The extractable condensed tannin content was the lowest for flowers （7.56±2.61 ） mg/g,and the highest for fruits （ 276.48 ± 9.62） mg/g and barks （254.71 ± 5.62 ） mg/g. The protein precipitation capacity was the highest in leaves and fruits, and the lowest in roots. 2. MALDI-TOF MS of the purified tannins from mature leaves of S. apetala revealed that they were hydrolysable tannins,in which galloyl group and glucose group were the basic units. The type of linkages between galloyl groups was through covalent bond.