The molecular structures of covalent adducts derived from flavins and 5-deazaflavins are discussed on the basis of racemization of atropisomeric flavins and 5-deazaflavins. The 5-adducts with SO32− and CN− underwent facile racemization, indicating that the molecular structure changes from the “tense” planar state to the “relaxed” bent state. On the other hand, the 4a-adduct prepared by the photo-alkylation method did not racemize at room temperature. This indicates that the structure of the 4a-adduct is different from the bent 5-adduct. These results provide an information useful to discuss the reduced state of flavoproteins.
基于旋光异构黄素和
5-脱氮黄素的消旋化,讨论了黄素和
5-脱氮黄素共价加合物的分子结构。5-加合物与SO32−和CN−发生简单的消旋化,表明分子结构从“紧张”的平面状态转变为“松弛”的弯曲状态。另一方面,通过光烷基化方法制备的4a-加合物在室温下不会发生消旋化。这表明4a-加合物的结构不同于弯曲的5-加合物。这些结果为讨论黄素蛋白的还原状态提供了有用的信息。