Peptide derivatives and medicinal compositions

摘要

The present invention to novel nociceptin receptor agonists which are peptide derivatives represented by the following general formula (1): (in which A is alkylene, -CH₂)_nCO- or a group expressed by the following formula (2) or (3): wherein n represents an integer of 1 to 8; X and Y are same or different and each represents -CONH- or -CH₂NH-; R¹, R² and R³ are same or different and each represents alkyl, aryl or heteroaryl; Z represents -CON(R⁴)R⁵ or -CH₂N(R⁴)R⁵; R⁴ and R⁵ are same or different and each represents hydrogen, alkyl, aryl or heteroaryl) or a pharmaceutically acceptable salt thereof. A pharmaceutical composition according to the present invention is useful as a nociceptin receptor agonist.