RESOLUTION OF FLURBIPROFEN BY AN ENTRAPPED LIPASE

长期目标是酶或活细胞的应用

The long-term goals are applications of enzymes or viable cells entrapped in polysaccharide beads. A literature example is entrapped islets of Langerhans which can behave as a bioartificial-pancreas. Initial research efforts will familiarize the investigator with the ex vivo kinetic resolution of enantiomers in organic media. Lipases in particular have proved to be faster and more enantioselective in esterification and transesterification reactions in organic media than in aqueous media. The proposed research also includes the incorporation of a lipase into beads for easy recovery and subsequent delivery of the enzyme. The short term goal is the resolution of the pharmacologically active enantiomer from an anti-inflammatory agent, flurbiprofen, by employing enantioselective esterification by the lipase entrapped within a polysaccharide matrix. Isolation of the active enantiomer will undoubtedly be a regulatory requirement in the near future because administering only the active enantiomer can reduce the toxicity and dose. There are distinct advantages to this method including a rapid, enantioselective reaction; repeated applications since the enzyme can be recovered: and terminal resolution in the synthesis sequence, which is economical. In the first year, the solvent and lipase will be optimized by evaluating which combination provides the fastest reaction, the greatest yield, and the highest enantioselectivity. In the second year, polysaccharide gel beads are fabricated to entrap the lipase. The successful polymer will provide a rugged, spherical matrix which can retain the enzyme, minimize interference with activity, and allow substrate and product diffusion. The permeability of the bead will be investigated by measuring the substrate diffusivity within the polysaccharide matrix. Kinetic parameters of the entrapped enzyme will be compared to those of the free enzyme in the third year. An efficiency factor will measure the entrapped to free enzyme activity. The stability of the bead, catalytic activity and enzyme retention will be evaluated as a function of repeated applications.