Novel peptide derivatives and their pharmaceutical use

摘要

Peptide derivatives of the following formula wherein R<1> and R<2> are the same or different and respectively mean hydrogen atom, a C1-5 alkyl group or phenyl, X is -NH-or -CH2-, Y is hydrogen atom, a benzyl group wherein phenyl may be substituted by hydroxyl, or a C1-5 alkyl group which may be substituted by -SH, -SR<3>, -SO2R<3>, -CONH2, -OR<6> or (wherein R<3> means a C1-5 alkyl group or an aryl group, R<4> and R<5> are the same or different and respectively mean hydrogen atom, a C1-5 alkyl group or an amino protecting group and R<6> is hydrogen atom, a C1-5 alkyl group or a hydroxyl protecting group), Z is -CH2- 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. 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.