DETERMINATION OF THE MOLECULAR-SPECIES COMPOSITION OF DIACYLGLYCEROLSIN HUMAN ADIPOSE-TISSUE BY SOLID-PHASE EXTRACTION AND GAS-CHROMATOGRAPHY ON A POLAR PHASE

The free diacylglycerols (DAGs) in adipose tissue are involved in the metabolism of stored lipids and hence are related to the supply of fat ty acids for other tissues. This paper describes a simple, fast, and r eproducible method for the identification and quantification of differ ent molecular species of DAGs in human adipose tissue. The method comp rised solid-phase extraction on a diol-bonded phase column combined wi th capillary GC analysis of silylated DAG derivatives on a polar phase (65% phenylmethylsilicone). Separation of the DAGs was achieved based on chain length, isomeric structure (1,2- and 1,3-DAGs), and degree o f unsaturation. The main DAGs were 1,2-OO, 1,2-OP, 1,2-LO and 1,2-LP. The composition was corroborated by analysis of the component fatty ac ids of the DAGs, 18:1(n-9), 16:0, and 18:2(n-6) being the three major fatty acids obtained. (C) 1998 Elsevier Science B.V. All rights reserv ed.