There's No Industrial Biocatalyst Like Hydrolase: Development of Scalable Enantioselective Processes Using Hydrolytic Enzymes

摘要

Chiral, racemic esters, ethyl(±)-tetrahydrofuran-2-carboxylate 4c, methyl (±)-α-phenylpropionate 9b, methyl (±)-5,5-dimethyl-1,3-thiazolidine-4-carboxylate 12a, 2-methoxyethyl (±)-1-(4-tert-butylphenyl)-2-oxopyrrolidine-4-carboxylate 15a, (±)-1-benzyloxy-3-chloropropan-2-yl hydrogen succinate 18c, and (±)-3-butyryloxyquinuclidinium butyrate [(±)-20b·n-PrCO_2H], are resolved kinetically by enantioselective hydrolysis catalyzed by an Aspergillus melleus protease [E = 60; 93.9% ee and 35% yield for (R)-tetrahydrofuran-2-carboxylic acid 4a], a Klebsiella oxytoca hydrolase [E > 200; 99.5% ee and 36% yield for (S)-α-phenylpropionic acid 9a], a K. oxytoca hydrolase [E = 145; 97.7% ee and 34% yield for (R)-5,5-dimethyl-1,3-thiazolidine-4-carboxylic acid 12b], a Bacillus brevis protease [E = 77; 99% ee and 45% yield for (S)-15a], a Serratia marcescence esterase [E = 49; 99% ee and 43% yield for (S)-18c], and an A. melleus protease [E = 96; 96% ee and 42% yield for (R)-20b], respectively. Each enzymatic process is discussed with focus on the following tactical issues: (1) identification of a hydrolase with high enantioselectivity, (2) substrate concentrations not less than 1 M that allow for industrially viable volume efficiency (space-time yield), (3) product separation by partition between organic and aqueous phases, and (4) alleviation of a hydrolysate inhibiting the enzymatic activity.