Cross-linked enzyme aggregates of pig liver esterase evaluated in kinetic resolution of racemic clopidogrel

• Background and Objective: Immobilization of enzymes as cross-linked aggregates is one of the cheapest, simplest and effective techniques for improving their stability and reusability and even avoiding contamination of the product with the catalyst. Clopidogrel is a widely used antiplatelet drug, only Sisomer is the biologically active enantiomer produced by resolution of the racemic compound. In the current study, cross-linked aggregates of pig liver esterase were prepared and evaluated for kinetic resolution of racemic clopidogrel. Materials and Methods: Cross-linked Enzyme Aggregates (CLEA) of the commercially available crude pig liver esterase cPLE were prepared using glutaraldehyde at concentrations of 12.5-125 mM as crosslinker either in presence or absence of Bovine serum albumin (BSA). cPLE-CLEA was used for kinetic resolution of racemic clopidogrel and compared to the performance of soluble cPLE. Light microscopy and scanning electron microscopy SEM were used to examine cPLE-CLEA. Results: Soluble cPLE showed ability to resolve racemic clopidogrel at enantioselectivity (E) of 9.2. The resolution of clopidogrel was found to be optimal at 30°C. The cPLE-CLEA preparations showed reduced enzymatic activity. The kinetic resolution experiments showed also lower E values (E = 1.3-4.5) compared to soluble cPLE. Microscopical examination of cPLE-CLEA showed wide size variation and SEM revealed the shape of cPLE-CLEA before and after use in the kinetic resolution experiments. Conclusion: Crude PLE was able to resolve racemic clopidogrel, the effects of different temperatures were studied and the highest E value recorded was 9.2 at 30°C. Increasing concentrations of glutaraldehyde as a cross-linker adversely affected PLE activity. The cPLE-CLEA showed lower enantioselectivity compared to the free cPLE.

Keyword

CLEA

Clopidogrel

Enantioselectivity

Esterase

Glutaraldehyde

Kinetic resolution

Publication and Content Type

art (subject category)

ref (subject category)