| abstract |
Peptide derivatives of the following formulan wherein R 1 and R 2 are the same or different and respectively mean hydrogen atom, a C 1 - 5 alkyl group or phenyl, X is -NH-or -CH 2 -, Y is hydrogen atom, a benzyl group wherein phenyl may be substituted by hydroxyl, or a C 1-5 alkyl group which may be substituted by -SH, -SR 3 , -S0 2 R 3 , -CONH 2 ,n -OR 6 orn (wherein R 3 means a C 1 - 5 alkyl group or an aryl group, R 4 and R 5 are the same or different and respectively mean hydrogen atom, a C 1 - 5 alkyl group or an amino protecting group and R 6 is hydrogen atom, a C 1 - 5 alkyl group or a hydroxyl protecting group), Z is -CH 2 - or -S-, and n is 1 or 2, provided that when X is -NH-, R 1 and R 2 are not hydrogen atoms at the same time, pharmaceutically acceptable acid addition salts thereof and pharmaceutical use thereof. n Since the compounds of the present invention possess stronger actions on central nervous system, they are of use as a therapeutic medicament for central nervous disorders. |