title: Hydrolysis and esterification of acylglycerols and analogs in aqueous medium catalyzed by microbial lipases.
abstract: The stereoselectivity of microbial lipases from Chromobacterium viscosum (CVL) and Rhizopus arrhizus (RAL) towards monoacylglycerols (rac-1(3)-oleoylglycerol and 2-oleoylglycerol), diacylglycerols (1,3-dioleoylglycerol and rac-1,2(2,3)-dioleoylglycerol) and 2-O-ether analogs (rac-1(3)-oleoyl-2-O-hexadecylglycerol and rac-1(3)-octanoyl-2-O-hexadecylglycerol) was determined. The results of the hydrolysis of 2-O-ether analogs confirmed the importance of the substituent at C-2 of acylglycerols in the stereoselective recognition by microbial lipases and also showed that acylation of mono- and diradylglycerols with oleic acid overlaps the hydrolysis reaction in aqueous medium. With the short-chain, water-soluble octanoic acid no significant esterification occurred. Using rac-1,2(2,3)-dioleoylglycerol as a substrate for the hydrolysis with RAL and CVL, the appearance of 1,3-dioleoylglycerol and of 1(3)-monooleoylglycerol was demonstrated. The possibility of chemical vs. enzyme-catalyzed isomerization of 1,2-dioleoylglycerol and of 2-oleoylglycerol is discussed.
authors.affiliation: Institut für Biochemie and Lebensmittelchemie, Technische Universität Graz, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Kovac
authors.forename: P
authors.initials: P
authors.lastname: Stadler
authors.forename: L
authors.initials: L
authors.lastname: Haalck
authors.forename: F
authors.initials: F
authors.lastname: Spener
authors.forename: F
authors.initials: F
authors.lastname: Paltauf
mesh_terms: D002861:Chromobacterium / Q000201:enzymology*; D004952:Esters / Q000378:metabolism; D005989:Glycerides / Q000378:metabolism*; D006868:Hydrolysis; D008049:Lipase / Q000494:pharmacology*; D008968:Molecular Conformation; D012233:Rhizopus / Q000201:enzymology*
chemical_list: D004952:Esters; D005989:Glycerides; D008049:Lipase