原花青素聚合作用机理研究进展

Progress on the Polymerization Mechanism of Proanthocyanidins during Their Biosynthesis

原花青素是一类通过植物类黄酮次生代谢途径合成的聚多酚类化合物,它具有抗紫外线、抗病、抗虫,清除自由基,调节种子休眠和萌发等生理功能。该文对近年来国内外有关原花青素的结构类型和生物合成机制、原花青素聚合作用机理(包括:原花青素的聚合作用发生在植物细胞中央大液泡、缩合过程中延伸单元前体可能为无色花青素、黄烷-3-醇和花青素等假说)、以及推测参与催化聚合反应的缩合酶(包括:植物多酚氧化酶、植物漆酶和植物过氧化酶)等方面的研究进展进行综述,为深入研究原花青素生物合成机制提供资料。

Proanthocyanidins are oligomers or polymers of flavan-3-ol units synthesized through plant flavonoid biosynthetic pathway,and have a variety of functions such as ultraviolet resistance,anti-microbial pathogens,anti-insect pests,scavenging free radicals,regulating plant seed dormancy and germination,etc.Here we concisely review the structures and types of proanthocyanidins and their biosynthesis,and intensively summarize recent main progress achieved in the understanding of the late steps of proanthocyanidin biosynthetic pathway,which includes these hypotheses that the polymerization of proanthocyanidin occurs in the vacuole of plant cells;precursors of extension units are leucoanthocyanidins,flanvan-3-ols or anthocyanidins,and related condensing enzymes are plant polyphenol oxidases,plant laccases or plant peroxidases involved in the polymerization reaction.The review provides certain new insights about proanthocyanidin biosynthesis.