CYCLIC PEPTIDE NUCLEI AND DERIVATIVES THEREOF

摘要

New peptide compounds of formula (I), wherein R<1> is alkyl or aralkyl, R<2> is amino(lower)alkyl or protected amino(lower)alkyl, R<3> is hydroxy, protected hydroxy, amino or protected amino, R<4> is hydroxy, or R<3> and R<4> are linked together to form -Z- (in which -Z- is -O- or -NH-), and R<5> is hydrogen or an amino protective group, R<6> is hydroxy, or R<5> and R<6> are linked together to form bond, with proviso that when R<3> is hydroxy, protected hydroxy, amino or protected amino and R<4> is hydroxy, then R<5> and R<6> are linked together to form bond, and a pharmaceutically acceptable salt thereof, which is useful as a medicament.