Tannins and related compounds. XLI. Isolation and characterization of novel ellagitannins, punicacorteins A, B, C and D, and punigluconin from the bark of Punica granatum L.
作者:TAKASHI TANAKA、GEN-ICHIRO NONAKA、ITSUO NISHIOKA
DOI:10.1248/cpb.34.656
日期:——
A chemical examination of the bark of Punica granatum L. (Punicaceae) has led to the isolation of five new ellagitannins, punicacorteins A, B, C and D, and punigluconin, together with the known ellagitannins, casuariin (6) and casuarinin (7). Based on chemical and spectroscopic evidence, the structures of punicacorteins A, B, C and D were established as novel C-glycosideic ellagitannins, the former two possessing a unique tetraphenyl (gallagyl) ester group (1 and 2), and the latter two containing a galloyl group in place of the gallagyl group (3 and 4), while punigluconin was characterized as 2, 3-di-O-galloyl-4, 6-(S)-hexahydroxydiphenoylgluconic acid (5).
对石榴(Punica granatum L.)树皮的化学分析导致分离出五种新的椰子单宁,分别是punicacorteins A、B、C和D,以及punigluconin,同时还发现了已知的椰子单宁,casuariin(6)和casuarinin(7)。基于化学和光谱证据,确定了punicacorteins A、B、C和D的结构为新型C-糖苷类型的椰子单宁,其中前两种具有独特的四苯基(gallagyl)酯基团(1和2),而后两种则在其位置替换为没食子酰基(3和4)。同时,punigluconin被表征为2, 3-二-O-没食子酰-4, 6-(S)-六羟基二苯酰葡萄糖酸(5)。