39 クロモプロテイン系エンジイン抗生物質の化学 : 常磁性を示す原理(口頭発表の部)

概要

論文の詳細を見る
A number of extremely potent enediyne antitumor antibiotics have been isolated from culture filtrates of Streptomyces species. Although these antibiotics are believed to generate p-benzyne-type biradicals through cycloaromatization, no direct EPR measurements of carbon radical species generated from enediyne antibiotics have been reported. A chromoprotein antibiotic, C-1027, which is powder of a 1:1 complex composed of a carrier apoprotein and a DNA cleaving enediyne chromophore (1), shows a steady EPR spectrum at room temperature. Here, we characterize three paramagnetic species existing in C-1027 antibiotic by EPR spectroscopy: a phenyl radical (3), a radical pair between a peptide carbon radical and 3, and a peroxy radical. These radical species are supplied constantly by dynamic processes through hydrogen abstraction by p-benzyne type biradical (2) from apoprotein. The present results provide strong evidence for equilibration between 1 and 2, and a chemical mechanism of deterioration leading to self-inactivation of the C-1027 antibiotic.
天然有機化合物討論会の論文
2000-10-01