Gary J. Calton

Enzymatic resolution of (R,S)-2-(4-hydroxyphenoxy) propionic acid

The enzymatic resolution of (R,S)-2-(4-hydroxyphenoxy)propionic acid was accomplished by treatment of the methyl ester in an aqueous/organic mixture with a number of commercially available Candida rugosa lipase preparations. With toluene as the organic phase, an enantiomeric excess of 88% to >99% could be obtained at 31% to 38% hydrolysis of the methyl ester.

Immobilization of enzymes with polyaziridines

A novel method of enzyme immobilization using a low molecular weight prepolymer of tri-functional aziridines which can immobilize enzymes both by covalent attachment and entrapment within a gel matrix is described. The enzymes are immobilized on a solid support and exhibit an excellent retention of enzymatic activity. The immobilization procedure is essentially a single step process which can be easily performed at room temperature or 4 degrees C in either aqueous solution or in an inert organic solvent. The polyaziridines used in the immobilization are nontoxic, available in bulk at low cost and completely miscible with water and many organic solvents, thus providing one of the most satisfactory methods of immobilization available.

Immobilization of enzymes with polyaziridine. II: D-amino acid oxidase

A novel method of enzyme immobilization using a tri-functional aziridine to immobilize enzymes was used to immobilize D-amino acid oxidase (DAAO) with good retention of enzymatic activity (62%–89%). The stability of the immobilized DAAO in a fixed bed reactor with continuous operation using D-phenylalanine as substrate yielded a projected half-life of 69 days which is far superior to other methods of immobilization of DAAO.