Screening of commercial enzymes for the enantioselective hydrolysis of R,S-naproxen ester

Abstract

This study focused on the identification of suitable lipase or esterase activity for enantiomeric resolution of (R,S)-naproxen. For an economically viable reaction the enantiomeric ratio (E) should preferably be >100, while maximising the conversion will reduce the mass of material that requires racemisation and recycling. Hence the aim was to find an enzyme that yields (S)-naproxen with an enantiomeric excess of more than 98%, a substrate conversion in excess of 40% of the racemate, and an E of >100. (R,S)-Naproxen ethyl ester (NEE) (50 mg) was used as substrate for enzyme hydrolysis reactions at 37 • C for 4 h. Biocatalyst screening was performed in buffered aqueous solvent on a 1 ml scale. The reactions were stopped with 2 ml MeCN, filtered through cotton wool and analysed by HPLC to determine the percentage m/m and R/S ratio.Eight commercially available enzymes were selected for optimisation of enantioselectivity through statistically designed experiments where the reaction conditions were varied. ChiroCLEC-CR from Altus and ESL001-01 from Diversa provided acceptable enantiomeric excess, but only ChiroCLEC-CR met the specification set for the enantiomeric ratio (E).

Improvement of Yarrowia lipolytica Lipase Enantioselectivity by Using Mutagenesis Targeted to the Substrate Binding Site

“…Enantiopure carboxylic acid esters are important building blocks for the synthesis of many pharmaceuticals (for instance nonsteroidal anti-inflammatory drugs such as Ibuprofen), pesticides, and natural compounds such as pheromones. [2][3][4][5] 2-halogeno-carboxylic acid esters are important intermediates found in the synthetic pathways of a number of drugs such as prostaglandin, prostacyclin, semisynthetic penicillin, and thiazolium salts. [6][7][8][9] In particular, 2-bromo-o-tolylacetic acid ethyl ester is used as a precursor for the synthesis of analgesics and nonpeptide angiotensin II-receptor antagonists.…”

Review- Alternatives for the separation of drug enantiomers: ibuprofen as a model compound

“…These transformations can be employed for the kinetic resolution of different chiral compounds (Sih, et al, 1988;Margolin, 1993;Carvalho et al, 2005b). Considerable efforts have been made to use racemic profens (2-arylpropionic acids) or their ester derivatives as the substrate in enantioselective esterification (De la Casa et al, 2002;Bhandarkar and Neau, 2000;Wu and Liu, 2000;Sánchez et al, 2000;Carvalho et al, 2005a), hydrolysis (Lee et al, 1995;Xin et al, 2000;Steenkamp and Brady, 2003;Long et al, 2005) or transesterification (Chang and Tsai, 1999;Santaniello et al, 1993) in order to produce the desired (S)-profens and their (S)-esters by employing lipases as the biocatalyst in the presence of organic solvents. Taking advantage of the naturally inherent selectivity of the enzyme's active site, reactive discrimination occurs between the enantiomers in the racemic mixture.…”

Lipase Catalyzed Synthesis of High Optical Purity (S) - Naproxen Starch Ester

“…Naproxen is widely used in therapeutics as analgesic and antipyretic and it is also used for relief of symptoms of rheumatoid arthritis and osteoarthritis in addition to treatment of dysmenorrheal, among other indications [3].The (S)-enantiomer is 28-fold more active than the corresponding (R)-enantiomer, (R)-isomer shows adverse side effects including renal impairment, gastrointestinal bleeding and platelet inhibition with altered haemostasis, warranting elimination of the unwanted enantiomer from the formulation [4]. Thus it was a good solution to generate (S) -naproxen starch ester.…”