Degradation of (+)-cyanidanol-3 by sodium sulfite in aqueous solution. II. Reactivity of several (+)-cyanidanol-3 derivatives with sodium sulfite.
作者:KOICHI AKIMOTO、ISAO SUGIMOTO
DOI:10.1248/cpb.32.3148
日期:——
The reactivity of several (+)-cyanidanol-3 (cianidanol) derivatives with sodium sulfite in aqueous solution was investigated at pH 7.5 and 60°C. 5, 7-O-Dimethylcianidanol was degraded by sodium sulfite to yield a water-soluble degradation product, which was assumed to be 5, 7-O-dimethylepicatechin carrying the sodium sulfonate function in place of the aliphatic hydroxy group at the C-3 position. The degradation by sodium sulfite was inhibited by the addition of boric acid and by lowering the pH of the solution to 3.0. On the other hand, 3', 4'-O-dimethylcianidanol and 5, 7, 3', 4'-O-tetramethylcianidanol were very stable in aqueous solution containing sodium sulfite. The mechanism of the attack of sulfite ion and/or bisulfite ion at the C-3 position of the dissociated form of cianidanol or 5, 7-O-dimethylcianidanol is discussed.
在 pH 7.5 和 60°C 的条件下研究了几种 (+)-cyanidanol-3(cianidanol)衍生物与亚硫酸钠在水溶液中的反应性。 5, 7-O-二甲基花椒醇被亚硫酸钠降解,产生水溶性降解产物,推测其为带有磺酸钠功能的 5, 7-O-二甲基表儿茶素,取代了 C-3 处的脂肪族羟基。位置。通过添加硼酸并将溶液的pH值降低至3.0来抑制亚硫酸钠的降解。另一方面,3',4'-O-二甲基氰胺醇和5,7,3',4'-O-四甲基氰胺醇在含有亚硫酸钠的水溶液中非常稳定。讨论了亚硫酸根离子和/或亚硫酸氢根离子攻击解离形式的氰胺醇或5,7-O-二甲基氰胺醇的C-3位的机理。