Degradation of Clavulanic Acid in Aqueous Alkaline Solution : Isolation and Structural Investigation of Degradation Products
作者:JUN HAGINAKA、HIROYUKI YASUDA、TOYOZO UNO、TERUMICHI NAKAGAWA
DOI:10.1248/cpb.33.218
日期:——
The degradation of potassium clavulanate in a weakly alkaline aqueous solution has been investigated. Potassium clavulanate was degraded in 0.1 M Na2HPO4 solution at various temperatures. Four degradation products were isolated and their structures were elucidated as 2, 5-bis-(2-hydroxyethyl) pyrazine (I), 3-methyl-2, 5-bis-(2-hydroxyethyl) pyrazine (II), 3-(2-carboxyethyl)-2, 5-bis-(2-hydroxyethyl) pyrazine (III). and 3-ethyl-2.5-bis-(2-hydroxyethyl) pyrazine (IV) by mass spectroscopy and nuclear magnetic resonance spectroscopy. High-performance liquid chromatographic analysis of the reaction solution indicated that the reaction at 60°C yielded all four pyrazine derivatives, whereas II was not formed at 35°C and III was not formed at 100°C. A reaction mechanism is proposed which involves 4-amino-3-oxobutanol (IX) as a key intermediate.
研究了克拉维酸钾在弱碱性水溶液中的降解情况。在不同温度下,克拉维酸钾在 0.1 M Na2HPO4 溶液中发生降解。通过质谱和核磁共振光谱分析,分离出四种降解产物,并阐明了它们的结构:2, 5-双-(2-羟乙基)吡嗪(I)、3-甲基-2, 5-双-(2-羟乙基)吡嗪(II)、3-(2-羧乙基)-2, 5-双-(2-羟乙基)吡嗪(III)和 3-乙基-2.5-双-(2-羟乙基)吡嗪(IV)。反应溶液的高效液相色谱分析表明,在 60°C 的温度下反应生成了所有四种吡嗪衍生物,而在 35°C 的温度下没有生成 II,在 100°C 的温度下没有生成 III。提出了一种以 4-amino-3-oxobutanol (IX) 为关键中间体的反应机理。