| abstract |
Amino acid derivatives of the formula ##STR1## wherein: Q is W--(CH 2 ) m --(A) n --CO--B-- wherein n A is oxygen atom or --NH--; n B is ##STR2## or --(CH 2 ) l -- wherein X is sulfur atom or --CH 2 --, and l is an integer from 1 to 3; n W is ##STR3## wherein Hal is halogen atom; n is an integer of 0 or 1; and n m is an integer from 0 to 3; n Y is sulfur atom or --CH 2 --; and n R is hydrogen atom, formyl group, C 1-5 alkoxycarbonyl group, --C.tbd.N or ##STR4## wherein R 1 is hydrogen atom, and n R 2 is hydroxyl group, C 1-5 alkylcarboxy group, phenylcarboxy group, C 1-5 alkoxy group or phenyl C 1-5 alkoxy group; n with the proviso that when R is hydrogen atom, formyl group or C 1-5 alkoxycarbonyl group, W is ##STR5## The compounds mentioned above specifically inhibit prolyl endopeptidase activity and are useful as agents for the treatment and prevention of dementia and amnesia. |