Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

Abstract

The ultrasound-assisted hydrolysis of aspirin methyl ester (AME) was investigated using immobilized Candida antarctica lipase B (CALB) (1%) in the presence of solvents like triolein, chloroform (CHCl) and dichloromethane (DCM). The effect of ultrasound and the role of water on the conversion rates have also been investigated. Proton nuclear magnetic resonance spectroscopic (H NMR) was chosen to calculate hydrolysis convertion rates. We observed that lipase-ultrasound assisted hydrolysis of AME in the presence of triolein and water showed the highest hydrolysis conversion rate (65.3%). Herein low water amount played an important role as a nucleophile being crucial for the hydrolysis yields obtained. Lipase activity was affected by the conjugated action of ultrasound and solvents (35.75% of decrease), however not disturbing its hydrolytic efficiency. It was demonstrated that lipase is able to hydrolyse AME to methyl 2-hydroxy benzoate (methyl salicylate), which applications include fragrance agents in food, beverages and cosmetics, or analgesic agent in liniments.

Ultrasound-assisted biosynthesis of novel methotrexate-conjugates

“…After removal of the reactional mixture from the US, followed by a liquid-liquid extraction of the unreacted triacylglycerols, only free MTX was recovered in the aqueous phase. This result was expectable since recently, Chiplunkar et al reported that immobilized CALB did not hydrolyse triolein in organic medium [23]. For the short triacylglycerols used, glycerol tributyrate (C 3 ), glycerol trivalerate (C 4 ) and glycerol trihexanoate (C 5 ), after 30 min under ultrasonication, we observed the disappearance of the biphasic system formed initially, and the precipitation of a solid that turns into soluble when more water is added to the reactional flask.…”

Chemical and enzymatic stability of the oleanoyl oxime ibuprofenate

“…The enzyme was also used to analyze the effect of water on the process of ultrasound‐assisted hydrolysis of methyl ester of acetylsalicylic acid (AME) in the presence of the CALB (1%) and in the medium of triolein, chloroform, and dichloromethane. It was demonstrated that lipase can hydrolyze AME into methyl 2‐hydroxybenzoate (methyl salicylate) that is used as a fragrance in the food and cosmetic industries as well as in the pharmaceutical industry as a topical analgesic (e.g., in liniment) …”

Improvement of adhesion properties of enzyme‐loaded coating on random packing in transesterification

“…Enzymes are well‐known as catalysts, which are characterized by high selectivity and activity . In addition, the use of enzymes generally reduces the amount of reaction steps and does not require functional group protection and/or activation . In short, enzymatic processes are more environmentally friendly, cost‐effective, and sustainable .…”

“…Among all lipases, Lipase B from Candida antarctica (CALB) is widely used as biocatalyst due to its high stereo selectivity, high activity, broad substrate specificity, high thermo stability and conformational stability . However, the thermal stability of free enzymes is limited, and their tolerance to organic solvents is very low .…”