Abstract
Two kinds of basic amino acid(L-Arginine(Arg) and p-guanidino-L-phenylalanine(GPA))deriva-tives of aspirin and ibuprofen were synthesized and the hydrolyses of these compounds by trypsin(Tp) and carboxypeptidase B(CPase B)were investigat-ed to evaluate the availability as prodrugs for aspirin and ibuprofen. The ester bonds of these compounds were hydrolyzed by Tp at from about one-tenth to half the rate of N-α-benzoyl-Arg ethyl ester, a specific substrate for Tp, suggesting that the compounds are good substrates for Tp. Salicylic acid was generated in the hydrolysis of aspirin-Arg by CPase B after the hydrolysis of aspirin-Arg to salicyl-Arg, while ibuprofen was released by CPase B from ibuprofen-Arg. On the other hand, aspirin-and ibuprofen-GPA were not hydrolyzed by CPase B at all. These results suggest that drug-Arg ethyl esters are useful in the design of the prodrugs for non-steroidal anti-inflamma-tory carboxylic acids.
