Preparation of (S)-2-Phenylpropionic Acid by CaCl2/CMC Nanoparticles Immobilized Candida rugosa Lipase-Catalyzed Hydrolysis in Micro Aqueous Mixed Organic Solvent Systems

Abstract

Candida rugosa lipase was immobilized in this study using CaCl2/CMC nanoparticles that yielded a lipase loading capacity of 127 mg/g, with better thermal stability and activity of 91.8%. The hydrolysis of racemic 2-phenylpropionic acid isopropyl ester by free and immobilized Candida rugosa lipase was investigated in the mixed organic-solvent composed of isooctane and methyl tert-butyl ether (9.5:0.5, V/V). The optimal conditions were 35 °C and pH 7.5 for free Candida rugosa lipase hydrolysis. We obtained (S)-2-phenylpropionic acid with 44.85% conversion, 95.75% enantiomeric excess and enantiomeric ratio of 112. The CaCl2/CMC nanoparticles immobilized Candida rugosa lipase possesses high enantioselectivity, with E = 237 at 40 °C and pH 7.5. It was efficiently reusable in four cycles and appropriately enhanced enantioselectivity within 120–240.