A chemical examination of mylobalans (the fruits of Terminalia chebula RETZ., Combretaceae) has led to the isolation and characterization of punicalagin (1), terflavin A (2) and a new ellagitannin named terchebulin (3), which possesses a anovel tetraphynylcarboxylic acid (terchebulic acid) moiety. Furthermore, from the leaves of T. chebula, a series of biogenetically related hydrolyzable tannins, terflavins B (7), C (9) and D (10), punicalagin (1) and punicalin (8), have been isolated and structurally elucidated. The concomitant isolation of terflavins A (2) and B (7) provides biogenetic evidence that the tervhebulic acid moiety is derived by an oxidative carbon-oxygen coupling of adjacent flavogallonic acid and gallic acid esters.
对乳香果(Terminalia chebula RETZ.,Combretaceae)的
化学检测,分离并鉴定出番石榴素(1)、terflavin A(2)和一种名为terchebulin(3)的新鞣花
单宁,后者具有一种新的四苯基
羧酸(terchebulic acid)部分。此外,从乳香果的叶子中分离出一系列
生物遗传相关的可
水解
单宁,terflavins B(7)、C(9)和D(10)、番石榴素(1)和番石榴素(8),并阐明了其结构。同时分离出的terflavins A(2)和B(7)提供了
生物遗传学证据,证明terchebulic acid部分是由相邻的
黄酮没食子酸和
没食子酸酯的氧化碳-氧偶联产生的。