Lipases-Catalyzed Ethanolysis Of Phosphatidylcholine And Effects Of Other Alcohols On The Ethanolysis

In this paper, the lysophosphatidylcholine (LPC) was prepared through alcoholysis ofsoybean phosphatidylcholine (PC) catalyzed by lipases (Lipozyme RM IM, Lipozyme TL IMand Novozym435) in n-hexane and solvent-free system, respectively. Based on the optimalethanolysis conditions of PC, the effect of other alcohols (n-butanol, turt-butanol,1,2-propylene glycol and glycerol) on the ethanolysis of PC was studied. Also the efficiencyof PC ethanolysis catalyzed by the mixed lipases in n-hexane were preliminary studied.The effects of n-butanol, turt-butanol,1,2-propylene glycol and glycerol on theethanolysis of Lipozyme RM IM catalyzed ethanolysis of PC in n-hexane and solvent-freesystem were studied respectively. The results showed that, in n-hexane, n-butanol andtert-butanol showed no significant stimulative or inhibitory action of on the ethanolysis of PC,while1,2-propylene glycol and glycerol showed significant inhibitory action of on theethanolysis of PC. In solvent-free system, n-butanol didn′t exhibit significant stimulative orinhibitory effect and tert-butanol showed inhibitory effect on ethanolysis of PC, while1,2-propylene glycol and glycerol both exhibited significant stimulative effect on ethanolysisof PC. Finally, glycerol was selected as substrate cooperating with ethanol, and theoptimization of Lipozyme RM IM-catalyzed alcoholysis of PC was determined by responsesurface methodology, the optimum conditions were temperature28℃, lipase dosage15%(based on the mass of PC), the amount of water8%(ratio of water to ethanol solution, v/v),glycerol10%(ratio of glycerol to ethanol solution, v/v), substrate concentration1.49g mL-1(PC/ethanol solution, m/v), reaction time11h.In n-hexane and solvent-free system, respectively, the effects of other alcohols on theLipozyme TL IM catalyzed ethanolysis of PC were studied. The results showed that, inn-hexane, n-butanol showed weakly inhibitory effect, turt-butanol showed weakly stimulativeeffect,1,2-propylene glycol showed no any significant stimulative or inhibitory effect andglycerol showed strong inhibitory effect on ethanolysis of PC. In solvent-free system, therewas no significant stimulative or inhibitory effect of n-butanol, weakly stimulative action of turt-butanol and inhibitory action of1,2-propylene glycol and glycerol on the ethanolysis ofPC.The effects of other alcohols on the Novozym435catalyzed ethanolysis of PC werestudied in solvent system and solvent-free system. We found that in n-hexane, turt-butanolshowed significant stimulative effect,1,2-propylene glycol showed no significant stimulativeor inhibitory effect, and n-butanol and glycerol exhibited inhibitory effect on the ethanolysisof PC. While in the solvent-free system, there was weakly stimμLative action of turt-butanol,inhibitory action of glycerol, and no significant stimulative or inhibitory action of n-butanoland1,2-propylene glycol on the ethanolysis of PC. Finally, turt-butanol was selected assubstrate cooperating with ethanol in n-solvent, and the optimization of Novozym435-catalyzed alcoholysis of PC was determined by response surface methodology, theoptimum conditions were temperature67℃, lipase dosage10%(based on the mass of PC),the amount of water48μL/g (water/PC, v/m), glycerol10%(ratio of glycerol to ethanolsolution, v/v), solvent ratio1:3(PC/n-hexane, m/v), substrate concentration1:2.89mol/mol(ratio of hydroxyl of ethanol to PC, n/n), turt-butanol concentration20%(molar ratio ofturt-butanol to ethanol solution), reaction time1.93h.In n-hexane, the catalytic efficiency of combound lipases-catalyzed ethanolysis of PCwas studied. The results showed that the catalytic efficiency of the ethanolysis of PCcatalyzed by the mixture of Novozym435and Lipozyme RM IM was close to that of with theefficiency catalyzed by Novozym435while the temperature increasing and the proportion ofthe Novozym435in the mixed lipase raising. The temperature and the ratio of Novozym435to Lipozyme TL IM showed no significant effects on the alcoholysis efficiency of PCcatalyzed by the mixture of Novozym435and Lipozyme TL IM, and the reaction efficiencyof PC ethanolysis catalyzed by the mixture of Novozym435to Lipozyme TL IM was similarto that of PC ethanolysis catalyzed by Lipozyme TL IM.