作者:Nils Mertens、Franziska Mai、Marcus A. Glomb
DOI:10.1021/acs.jafc.8b06458
日期:2019.2.13
In the present study the enzymatic oxidation of gallic acid and catechin catalyzed by nashi pear polyphenol oxidase (PPO) in the presence of the amino acids lysine, arginine, or cysteine was investigated for polyphenol–amino acid adducts. HPLC analyses revealed the formation of two novel dihydrobenzothiazine carboxylic acid derivatives (8-(3’,4’-dihydro-2H-chromene-3’,5’,7’-triol)-3,4-dihydro-5-hy
在本研究中,研究了在存在赖氨酸,精氨酸或半胱氨酸氨基酸的情况下,由纳西梨多酚氧化酶(PPO)催化的没食子酸和儿茶素的酶促氧化作用,研究了多酚-氨基酸加合物的存在。HPLC分析表明形成了两种新型的二氢苯并噻嗪羧酸衍生物(8-(3',4'-dihydro-2 H -chromene-3',5',7'-triol)-3,4-dihydro-5-hydroxy -2 H-苯并噻嗪-3-羧酸和7-(3',4'-二氢-2 H-色烯-3',5',7'-三醇)-3,4-二氢-5-羟基-2 H分别在2'-半胱氨酸儿茶素和5'-半胱氨酸儿茶素中孵育2-半胱氨酸儿茶素。相反,精氨酸和赖氨酸没有导致任何氨基酸加合物。通过高效逆流色谱和制备型HPLC分离目标化合物,并通过质谱和核磁共振波谱明确表征。从儿茶素-半胱氨酸加合物开始的机理研究表明,儿茶素和PPO都是二氢苯并噻嗪形成过程中的关键组成部分。半胱氨酸温育显示出