Improvement of catalytic activity of lipase in the presence of wide rim substituted calix[4]arene carboxylic acid-grafted magnetic nanoparticles

Candida rugosa lipase immobilized on calix[4]arene carboxylic acid-grafted magnetic nanoparticles using a sol–gel encapsulation technique was tested for activity, which was assessed both in the enantioselective hydrolysis of racemic Naproxen methyl ester and that of p-nitrophenylpalmitate. It has also been noticed that, compared to the free enzyme (E = 137) with an ee value of >98 %, S-Naproxen calix[4]arene carboxylic acid-grafted magnetic nanoparticles based on encapsulated lipase (Calix-1-MN and Calix-2-MN) offer excellent enantioselectivity (E = 373 and E = 381). Moreover, the results indicated that after the fifth reuse in the enantioselective reaction, the encapsulated lipase (Calix-2-MN) still retained about 43 % of its conversion power.