SYNTHESIS OF L-TYROSINE GLYCERYL ESTER CATALYZED BY ALPHA-CHYMOTRYPSIN IN WATER-MISCIBLE ORGANIC-SOLVENTS - A POSSIBLE SUN-TAN ACCELERATOR PRODUCT

The synthesis of L-tyrosine glyceryl ester, from glycerol and L-tyrosi ne methyl ester, was carried out by a transesterification reaction cat alyzed by alpha-chymotrypsin. Values of 60 % (v/v) for glycerol and 20 0 mM for L-tyrosine methyl ester were optimal for the transesterificat ion reaction. Additionally to glycerol, several other water miscible c osolvents (acetonitrile, N,N'-dimetyl formamide and tetrahydrofurane) were tested in the reaction media, but their presence did not give an enhancement on the transesterification activity with respect to the gl ycerol/water medium. However, increasing the hydrophobicity of the cos olvent resulted in a reduction of the enzyme activity, the water:glyce rol mixture being the best reaction media.