Experiments and speculations on the role of oxidative cyclization chemistry in natural product biosynthesis
作者:Craig A Townsend、Amit Basak
DOI:10.1016/s0040-4020(01)81792-0
日期:——
3′-2H2]proclavaminic acid, (22) and (29) respectively, are described. These labeled substrates were incubated with clavaminate synthase, a key enzyme acting in the biosynthesis of the lactamase inhibitor clavulanic acid, in the presence of ferrous ion, α-ketoglutaric acid and molecular oxygen. The apparent oxidative cyclization/desaturation chemistry evident in the conversion of proclavaminic acid (8) to clavaminic
[22的合成H,3- 13 C] -和[22 H,3'- 2 ħ 2 ] proclavaminic酸,(22)和(29)分别进行了描述。这些标记的底物在亚铁离子,α-酮戊二酸和分子氧的存在下,与内酰胺酶抑制剂克拉维酸的生物合成中起作用的关键酶谷氨酸合酶孵育。表观氧化环化/去饱和化学在proclavaminic酸(转化明显8)至clavaminic酸(9)发生时不会丢失或交换底物中C-2和C-3'处的标记。这些观察结果表明与天然产物生物合成中的硫插入反应具有显着相似性,并导致提出了一种氧化环化的普遍机制,该机制涉及底物杂原子的参与。通过扩展这一机械学说,人们提出了一种新的生物遗传学方法来解释聚醚的形成,例如,莫能菌素(52)和短肠毒素A(55)中的聚醚形成。