Resolution of DL-2-aminosuberic acid via protease-catalyzed ester hydrolysis.

Papain-catalyzed regioselective cleavage of alpha-methyl ester in Z-DL-Asu(OMe)-OMe leads to Z-L-Asu(OMe)-OH and Z-D-Asu(OMe)-OMe. Subsequent saponifications yield Z-L-Asu-OH and Z-D-Asu-OH. The enzymatic alpha-ester hydrolysis was also achieved by subtilisin BPN' in organic solvent with low water content.