作者:Jack E. Baldwin、Robert M. Adlington、Nicholas P. Crouch、Christopher J. Schofield、Nicholas J. Turner、Robin T. Aplin
DOI:10.1016/s0040-4020(01)80725-0
日期:1991.12
orin C synthase (DAOC/DAC synthase) from Cephalosporium acremonium CO 728 gave in addition to the expected products, deacetoxycephalosporin C and deacetylcephalosporin C, a third β-lactam metabolite as a 3β-hydroxy-3α-methylcepham (9a). Production of the 3β-hydroxycepham was promoted from [3-2H]penicillin N (3b) which was rationalised by the operation of a kinetic isotope effect on a branched pathway
青霉素N(3a)与顶头孢霉CO 728的部分纯化的脱乙酰氧基/脱乙酰头孢菌素C合酶(DAOC / DAC合酶)一起温育后,除了预期的产品,脱乙酰氧基头孢菌素C和脱乙酰头孢菌素C也作为第3种β-内酰胺代谢产物β-内酰胺。羟基-3α-甲基cepham(9a)。[3- 2 H]青霉素N(3b),这是通过在酶促过程中对分支途径的动力学同位素效应进行操作来合理化的。已显示3β-羟基的氧部分衍生自分子氧。另外,显示出青霉素N的2β-甲基被结合到3β-羟基-3α-甲基cepham的C2中,结果在立体化学上与青霉素N的2β-甲基等效地转化为脱乙酰氧基头孢菌素的C2相同。 C 1。提供了与这些观察结果一致的机械解释。