title: Synthesis of retinyl palmitate catalyzed by Candida sp.99-125 lipase immobilized on fiber-like SBA-15 mesoporous material.
abstract: Candida sp.99-125 lipase was suitable for transesterification of fats and oils to produce fatty acid methyl ester. The adsorption of Candida sp.99-125 lipase onto the fiber-like SBA-15 mesoporous material has been studied. The unaltered structural order of the fiber-like SBA-15 before and after the adsorption has been confirmed by FT-IR, SEM and N2 adsorption. The amount of adsorbed Candida sp.99-125 lipase depends both on the solution pH and reaction time. Good adsorption capacity of Candida sp.99-125 lipase on fiber-like SBA-15 may be due to solution pH from 5.0 to 9.0 especially at 7.0 (93.99 mg enzyme per gram silica is obtained and the activity recovery is 281.05%). A high lipase loading (135.9 mg enzyme per gram silica) was obtained, but it did not produce a proportionate level of catalytic activity. The immobilized Candida sp.99-125 lipase showed increased adaptability in the hydrolysis of p-nitrophenyl acetate compared to free Candida sp.99-125 lipase at pH 5.0-9.0. Meanwhile, the immobilized Candida sp.99-125 lipase showed higher thermal stability than that of free Candida sp.99-125 lipase. And the synthesis of retinyl palmitate in organic solvent with the immobilized Candida sp.99-125 lipase was investigated. The influence factors, such as: the solvent used, the molar ratio and concentrations of substrates, the reaction time and the amount of lipase were studied and optimized. In the conditions of transesterificating 0.164 g retinyl acetate and 0.32 g palmitic acid, 10 mL of solvent hexane, 1:4 of mass ratio of lipase to retinyl acetate, and 6 hours of reaction time, 74.6% of retinyl acetate was converted into retinyl plamitate.
authors.affiliation: College of Life Science and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing, 210009, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Kai
authors.forename: Wang
authors.initials: W
authors.lastname: Jianqiang
authors.forename: Wang
authors.initials: W
authors.lastname: Yan-hua
authors.forename: Liu
authors.initials: L
authors.lastname: Hui
authors.forename: Han
authors.initials: H
authors.lastname: Ping-fang
authors.forename: Wei
authors.initials: W
authors.lastname: Ping
mesh_terms: D000327:Adsorption; D055162:Biocatalysis; D002175:Candida / Q000201:enzymology*; D004224:Diterpenes; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D000084562:Retinyl Esters; D012822:Silicon Dioxide / Q000737:chemistry*; D014801:Vitamin A / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism
chemical_list: D004224:Diterpenes; D004800:Enzymes, Immobilized; D000084562:Retinyl Esters; C509969:SBA-15; D014801:Vitamin A; C014794:retinol palmitate; D012822:Silicon Dioxide; D008049:Lipase