Peptide derivative, pharmaceutically acceptable salt thereof, process for producing the same, and use thereof

摘要

The present invention provides a peptide derivative of formula (I) or a pharmaceutically acceptable salt thereof wherein X is -CH(OH)- or -CO-; R<1> is hydrogen or an amino protecting group; R<2> is hydroxyl or lower alkoxy; one of R<3> and R<4> is the side chain (R group) of lysine the amino group of which may be protected with a protecting group and the other of R<3> and R<4> is the side chain (R group) of arginine the guanidino group of which may be protected with a protecting group; and R<5> and R<6> may be the same or different and are hydrogen, lower alkyl or aralkyl. The present invention further provides a production process and use thereof.