Synthesis ofL-[3,3,4,4,S-methyl-2H7]methionine for use as a substrate for the methionine loading test
作者:Hiroshi Hasegawa、Yoshihiko Shinohara、Kazunori Tagoku、Takao Hashimoto
DOI:10.1002/jlcr.428
日期:2001.1
Optically pure L-[3,3,4,4,S-methyl-2H7]methionine (L-[2H7]-methionine) for use as a substrate for the methionine loading test has been prepared. The racemic [2H7]methionine was prepared from DL-[3,3,4,4-2H4]methionine (DL-[2H4]methionine) by conversion of the S-CH3 group to a C2H3 group. The racemate was resolved by stereospecific hydrolysis of the N-acetylated derivative with acylase. After an intravenous administration of L-[2H7]methionine in a rat, the concentration of L-[2H7]methionine and the metabolites in plasma were determined by GC-MS-SIM. L-[2H4]Homocysteine and L-[2H4]methionine were detected in plasma at 30 min after dosing. These results show that L-[2H7]methionine was converted by de-methylation and subsequent re-methylation to form L-[2H4]methionine. Copyright © 2001 John Wiley & Sons, Ltd.
已制备光学纯L-[3,3,4,4,S-甲基-2H7]蛋氨酸(L-[2H7]蛋氨酸),作为蛋氨酸负荷测试的底物。该外消旋体[2H7]蛋氨酸是通过将DL-[3,3,4,4-2H4]蛋氨酸(DL-[2H4]蛋氨酸)的S-CH3基团转化为C2H3基团制备的。通过与酰化酶的立体特异性水解,分离了外消旋混合物。在给大鼠静脉注射L-[2H7]蛋氨酸后,通过气相色谱-质谱-选择离子监测(GC-MS-SIM)测定了L-[2H7]蛋氨酸及其代谢物在血浆中的浓度。L-[2H4]同型半胱氨酸和L-[2H4]蛋氨酸在给药后30分钟时在血浆中被检测到。这些结果表明,L-[2H7]蛋氨酸通过去甲基化和随后的再甲基化转化为L-[2H4]蛋氨酸。版权所有 © 2001 John Wiley & Sons, Ltd.