| 摘要 |
A pharmacologically active cyclic peptide of formula (I), or a pharmaceutically acceptable salt thereof: <CHEM> wherein R1 and R2 are independently (CH2)nNH2 or (CH2)nNH-C=NH.NH2 wherein n is 3-6; R3 is CH2R7 wherein R7 is phenyl optionally substituted by one or two substituents selected from halogen, hydroxy, C1-4 alkyl and C1-4 alkoxy, or R7 is C1-6 alkyl; R4, R5 and R6 are the same or different C1-7 alkyl groups; four of X<1> to X<6> are amide linkages and the other two are amide linkages or linkages wherein the amide bond is replaced by an enzyme stabilised linkage; provided that, when R7 is phenyl, at least one of the three carbon atoms depicted in formula (I) attached to R4, R5 and R6, is in the L-configuration. |
