Analysis of medium-chain acyl-coenzyme A esters in mouse tissues by liquid chromatography–electrospray ionization mass spectrometry

Abstract

Medium-chain acyl-coenzyme A (CoA) esters are key metabolites in lipid metabolism. Liquid chromatography-electrospray ionization mass spectrometry analysis of medium-chain acyl-CoA esters is described. Eight medium-chain acyl-CoA esters were well separated on a C 8-MS reversed-phase column using a linear gradient of ammonium acetate buffer (pH 5.3)–acetonitrile. The positive-ion mass spectra of all the saturated and unsaturated medium-chain acyl-CoA esters gave dominant [M + H] + ions, whereas their negative-ion mass spectra showed abundant [M − H] − and [M − 2H] 2− ions. The positive-ion mode of operation was slightly less sensitive than the negative-ion detection mode. Five medium-chain acyl-CoA esters of C 6:0, C 8:0, C 8:1, C 10:0, and C 10:1 in liver, heart, kidney, and brain from the mouse were identified. The predominant acyl-CoA peaks were C 6:0, C 8:0, and C 10:0. Small amounts of medium-chain acyl-CoAs of C 8:1 and C 10:1 were detected only in heart and kidney. The analytical method is very useful for the analysis of medium-chain acyl-CoA esters in the tissues.