Amino acid starter unit in the biosynthesis of macrolactam polyketide antitumor antibiotic vicenistatin
作者:Hiroshi Nishida、Tadashi Eguchi、Katsumi Kakinuma
DOI:10.1016/s0040-4020(01)00820-1
日期:2001.9
on the starter unit of antitumor antibiotic vicenistatin were undertaken by feeding experiments with (2S,3R)- and (2S,3S)-3-[2H3]methylaspartate, and 3-amino-2-[2H3]methylpropionate. The starter unit of the macrolactam part of vicenistatin was found to be derived from (2S,3S)-3-methylaspartate, but not from the (2S,3R)-isomer. The present as well as the previous results suggest that the starter is formed
通过饲喂(2 S,3 R)-和(2 S,3 S)-3- [ 2 H 3 ]甲基天冬氨酸和3-氨基-2- [ 2 H 3 ]丙酸甲酯。发现抗维斯他汀大内酰胺部分的起始单元衍生自(2 S,3 S)-3-甲基天冬氨酸,而不衍生自(2 S,3 R)-异构体。目前和以前的结果表明,起始物是由谷氨酸通过谷氨酸突变酶催化的结构重排形成的(2S,3 S)-3-甲基天冬氨酸酯,其随后被装载到聚酮化合物合酶上。在活化或缩合过程中,可能会发生额外的差向异构和脱羧,以得到最终的C-18立体化学。