摘要
Abstract
In this study,we quantified the overall pools of phenolics in the leaves of Kandelia obovata (Sheue,Liu & Yong),and i-dentified the major constituents of these pools and stated their changes during leaf maturation and senescence.The contents of poly-phenolics ((144.73±8.56)mg/g to (38.79±2.14)mg/g)and soluble condensed tannins ((128.44±12.73)mg/g to (19.87± 2.45)mg/g)first decreased and then increased from bud to older leaves.The lowest content of polyphenolics and soluble condensed tannins appeared in the third mature leaves,as they showed the strongest physiological activity.Meanwhile,we used HPLC to identify the relative contents of degradation products of tannins (delphinidin,anthocyanin and pelargonidin),thus to distinguish the structure differences of tannins.Among them,the content of anthocyanin was found to be relatively high and constant.The content of delphini-din was lower in bud and young leaves,and increased gradually in older leaves.In contrast,the content of pelargonidin was higher in bud,while no significant difference was observed among other tissues.Hence,it suggested that the hydroxyl number of tannins in-creased from young to older leaves.Moreover,we used MALDI-TOF MS to analyze the tannins structure among the plant tissues.The results showed that the chemical structure of condensed tannins included 13 types of polymers (from dimer to tetradecamer).Specif-ically,the tannins polymers were combined with glucoside from the third pair leaves,particularly in the fifth and sixth pair leaves, which were senescent leaves.Our results reveal the changes in relative content and chemical structure of tannins at the different de-velopmental stages of K.obovata,and provide the essential basis for studying the function of tannins to the coastal ecosystem.关键词
秋茄/单宁/动态变化Key words
Kandelia obovata(Sheue/Liu & Yong)/tannins/dynamic change分类
农业科技
