植物多酚(英文)

从普遍存在的绿原酸到分子量在500—20000范围之间的多酚组分(即植物单宁)植物多酚的变化是很复杂的。从广义上讲,多酚主要可分为两类,即原花色素和以倍酸和(或)六羟基联苯甲酸和它们的衍生物为基础的聚酯化合物。如早期文献报道的,前者相当于凝缩类单宁,而后者则是水解单宁。作为植物的二次代谢物它们具有一些不同的分子特性。它们不仅具有多种多样酚基,而且还有一种和各种天然大分子即蛋白、多糖和核酸以及代谢物如生物碱结合成可逆复合物的倾向。根据这些性质,历史上按“伞”命名法称之为植物单宁。文中还讨论了植物多酚结构的变化因素,以及它们与其它物质的结合。

PLANT POLYPHENOLS

Plant phenols vary in complexity from the ubiquitous chlorogenic acid to po-lyphenolic compounds (syn.vegetable tannins)with molecular weights in the range 530-20,000 and beyond. Polyphenols are broadly divisible into two major groups -the proanthocyanidins and the polyesters based on gallic acid and/or hexa-hydroxydiphenic acid and their derivatives. As recorded in earlier literature the former category corresponds with that of the condensed and the latter the hydro-lysable tannins. As plant secondary metabolites they possess several distinctive molecular characteristics. Not only do they carry a multiplicity of phenolic groups but they have a propensity to reversibly complex with various natural macro-molecules- proteins, polysaccharides and nucleic acids-and metabolites such as alkaloids. Various facets of the structule of plant polyphenols and their complexation with other substrates will be discussed.