Synthesis of structured triacylglycerols containing medium-chain and long-chain fatty acids by interesterification with a stereoespecific lipase fromMucor miehei.

The preparation of structured triacylglycerols sn-1, sn-3 dilauryl, sn-2 el cosapentaenoyl glycerol and sn-1, sn-3 dilauryl, sn-2 docosahexaenoyl glyce rol by enzymatic interesterification under restricted water availability is described. Lauric acid, one of the substrates for interesterification, was obtained by the controlled hydrolysis of coconut oil by a non-specific lip ase obtained from Candida cylindracea. The fatty acid was separated from th e hydrolysis products by silver-resin column chromatography and converted t o methyl ester. sn-2 Eicosapentaenoyl glycerol and sn-2 docosahexaenoyl gly cerol were prepared by the hydrolysis of fish oil by the sn-1, sn-3 stereos pecific immobilized lipase Lipozyme IM-20 obtained from Mucor miehei as des cribed in the accompanying paper. The interesterification was carried out i n a water jacketed glass reactor and the triacylglycerol products were sepa rated and recovered through aluminum oxide column chromatography. The inter esterification procedure described allows to obtain in laboratory scale str uctured triacylglycerols containing medium-chain far, acids at the sn-l and sn-3 positions and long-chain polyunsaturated fatty acid from marine origi n at the sn-2 glycerol position.