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

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. (C) 2003 Elsevier Inc. All rights reserved.