Lipase-Mediated Deacetylation and Oligomerization fo Lactonic Sophorolipids

摘要

The direct enzymatic polymerization of lactonic sophorolipids (SLs) was investigated with four lipases,including porcine pancreatic lipase (PPL) immobilized Mucor miehei lipase (MML) lyophilized Candida antarctica lipase (Fraction B,CAL-B) and lyophilized Pseudomonas sp.lipase (PSL).Several organic solvents,covering a wide range of polarity,were compared for suitability as the reaction medium.Isopropyl ether and toluene were found most effedtive.According to the quantification adn structure identification by HPLC and LC-MS the reaction proceeded with the formation of monoacetylated lactionic SLs and the subsequent conversion of the intermediates to oligomers and polymers presumably through ring-openine poly-merization.Temperature was found to have signifcant effets on the reaction.Bot the conversion of reactant SLs and the subequent formation of oligomers and polymers from the intermediates were faster at 60 deg C than at 50 deg C The substrate selectivity among the three dominate readtant SLs also differed with the temjperature,The conversion rate increased with the ring size of the lactones at 60 deg C but it decreased iwht the size at 50 deg C