Ultrasound Effects On The Activity And Enantioselectivity Of Candida Rugosa Lipase In Organic Solvents

This work reports a study on the effect of ultrasound on the behavior of Candida rugosa lipase in the enantioselective transesterfication of some racemic secondary alcohols (1phenylethanol, 2-pentanol, menthol) with different acyl donors (vinyl acetate, vinyl propionate, vinyl butyrate) in the presence of organic solvents. The experiments were conducted with two different approaches: ultrasonic irradiation without stirring and stirring after ultrasonic pre-irradiation of lipase. The same experiments were conducted under conventional stirring to evaluate the effect of the ultrasound. The influence of preirradiation time, organic solvents, acyl donors and temperature were investigated. With the two approaches, the ultrasound has advantage over the conventional stirring. The best results were, however, obtained when the reactions were conducted under ultrasound without stirring. In the resolution of the menthol by vinyl acetate in hexane, the conversion increased 3-fold and the enantioselectivity 5-fold