Synthesis of selectively labeled histidine and its methylderivatives with deuterium, tritium, and carbon-14

摘要

Isotopologues of L-histidine and its A/-methylderivatives labeled with deuterium and tritium at the 5-position in the imidazole ring were obtained using the isotope exchange method. The deuterium-labeled isotopologues [5-~2H]-L-histidine, [5-~~2H]-N-methyl-L-histidine, [5-~~2H]-N~pi-methyl-L-histidine, and [2,5-~~2H_2]-L-histidine were synthesized by isotope exchange method carried out in a fully deuterated medium with. The same reaction conditions were applied to synthesize [5-~3H]-N-methyl-L-histidine, [5-~3H]-N-methyl-L-histidine, and [5-~3HR-histidine with specific activity of 2.0, 5.0, and 2.6 MBq/ mmol, respectively. The Npi-[methyl-~(14)C]-histamine was obtained with specific activity of 0.23 MBq/mmol in a one-step reaction by the direct methylation of histamine by [~(14)C]iodomethane.