MOLECULAR RECOGNITION FOR THE ENANTIOSELE CTIVE HYDROLYSIS OF AMINO-ACID ESTERS IN FUNCTIONAL MOLECULAR ASSEMBLY SYSTEMS

Enantioselective hydrolysis of amino acid esters by L-histidine deriva tives in the molecular assemblies composed of single- and double-chain surfactants was investigated. The remarkably high enantioselectivity (k(a,obsd)(L)/k(a,obsd)(D)=1000) was attained for the hydrolysis of lo ng-chained substrates (N-dodecanoyl-D(L)-phenylalanine p-nitrophenyl e ster; C-12-D(L)-Phe-PNP) catalyzed by the active tripeptide loxycarbon yl)-L-phenylalanyl-L-histidyl-L-leucine; Z-Phe-HisLeu) in the coaggreg ate systems composed of 41 mol% hexadecyltrimethylammonium bromide (CT AB) and 59 mol% ditetradecyldimethylammonium bromide (2C(14)Br) at the specific ionic strength (mu=0.02). Furthermore, the computer modeling (MOPAC calculation) study suggests that a favorable molecular recogni tion between the substrate and the catalyst through the effective hydr ophobic interactions and hydrogen bonds should be very important for t he enhancement of enantioselectivity.