Lee Seung-Ho, Tanaka Takashi, Nonaka Gen-ichiro, Nishioka Itsuo
Faculty of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
J Nat Prod. 2004 Jun;67(6):1018-22. doi: 10.1021/np0400297.
A new ellagitannin, jolkinin (2), was isolated from the fresh whole plant of Euphorbia jolkinii, and its structure, including absolute configuration, was determined on the basis of spectroscopic and chemical evidence. A highly oxygenated acyl group with unique hexacyclic structure is attached to the 2,4-positions of 1-O-galloyl-3,6-(R)-hexahydroxydiphenoyl-beta-d-glucopyranose. The structural similarity to elaeocarpusin (4) suggests that jolkinin is produced by a condensation reaction between ascorbic acid and geraniin (1), the dominant ellagitannin in this plant, which contains a dehydrohexahydroxydiphenoyl group. A plausible mechanism for jolkinin formation is also proposed.
从泽漆新鲜全草中分离出一种新的鞣花单宁——jolkinin（2），并根据光谱和化学证据确定了其结构，包括绝对构型。一个具有独特六环结构的高度氧化酰基连接在1-O-没食子酰基-3,6-(R)-六羟基二苯甲酰基-β-D-吡喃葡萄糖的2,4位上。与油榄素（4）的结构相似性表明，jolkinin是由抗坏血酸和香叶木素（1）（该植物中主要的鞣花单宁，含有一个脱氢六羟基二苯甲酰基）之间的缩合反应产生的。还提出了jolkinin形成的一种合理机制。
