Synthesis of Carnosine-d₇ and Anserine-d₄ for Use as Internal Standards in Liquid Chromatography–Mass Spectrometry

Abstract

A convenient synthesis of carnosine-d₇ and anserine-d₄ is described. Coupling of N-Boc-β-alanine-d₄ with L-histidine-d₃ or 1-methyl-L-histidine using isobutyl chloroformate afforded the corresponding Boc-protected dipeptide. Subsequent Boc group deprotection with hydrochloric acid yielded carnosine-d₇ and anserine-d₄ in 46% and 69% overall yield, respectively.

Keywords:

• Anserine-d₄
• carnosine-d₇
• deuterated compound
• dipeptide
• LC-MS

ACKNOWLEDGMENTS

This work was supported by the National Institute of Mental Health under Contract N01-MH-32005. The authors thank Ms. Terri Komar and Ms. Ann Allen for technical assistance during preparation and submission of this manuscript.