Kunishima Munetaka, Kitao Akiko, Kawachi Chiho, Watanabe Yasunobu, Iguchi Shin, Hioki Kazuhito, Tani Shohei
Faculty of Pharmaceutical Sciences and High Technology Research Center, Kobe Gakuin University, Japan.
Chem Pharm Bull (Tokyo). 2002 Apr;50(4):549-50. doi: 10.1248/cpb.50.549.
Racemization of the C-terminal amino acid (Ala) has been studied in various solvents during coupling between 4-methoxybenzyloxycarbonyl (Z(OMe))-Gly-L-Ala-OH and phenylalanine benzyl ester (H-Phe-OBzl) with 4-(4,6-dimethoxy-1,3,5-thiazin-2-yl)-4-methylmorpholinium chloride (DMT-MM). The reaction occurred without substantial racemization in AcOEt, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), CH3CN, and 2-PrOH, while a slight racemization was observed in dimethyl sulfoxide (DMSO), EtOH, and MeOH. The extent of racemization may correlate with the polarity of the solvents.
在4-甲氧基苄氧羰基(Z(OMe))-甘氨酰-L-丙氨酸-OH与苯丙氨酸苄酯(H-Phe-OBzl)在4-(4,6-二甲氧基-1,3,5-噻嗪-2-基)-4-甲基吗啉鎓氯化物(DMT-MM)作用下的偶联反应过程中,已对C端氨基酸(丙氨酸)的消旋化在各种溶剂中的情况进行了研究。该反应在乙酸乙酯、四氢呋喃(THF)、N,N-二甲基甲酰胺(DMF)、乙腈和2-丙醇中进行时没有明显的消旋化现象,而在二甲基亚砜(DMSO)、乙醇和甲醇中观察到了轻微的消旋化。消旋化程度可能与溶剂的极性相关。