Patent ID: 8247530

Claim:
A cyclic peptide of the structural formula: wherein: R 1 is H, NH 2 , R 2 is —C(═O)—NH—, —NH—C(═O)—, —S—, or —S—S—; R 3 is 4-imidazolyl or 3-indolyl; R 4a and R 4b are each optional ring substituents, and when one or both are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage; R 5 is —NH 2 or —NH(C═NH)NH 2 ; R 6 is 1- or 2-naphthyl or 3-indolyl, optionally with one or two ring substituents, and when one or both ring substitutents are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage; R 7a and R 7b are each independently H or a C 1 to C 4 linear or branched alkyl chain, on the proviso that both R 7a and R 7b are not H; R 8 is H, NH 2 , a lower aliphatic C 1 to C 4 branched or linear alkyl chain, a C 1 to C 4 aralkyl, or a C 1 to C 4 omega amino aliphatic chain; R 9 is H, a lower aliphatic C 1 to C 4 branched or linear alkyl chain, a C 1 to C 4 aralkyl, or a C 1 to C 4 omega amino aliphatic chain; R 10 is an aliphatic L- or D-amino acid, an N-acylated L- or D-amino acid or a linear or branched C 1 to C 17 alkyl, aryl, heteroaryl, alkene, alkenyl, or aralkyl chain; x is 1 to 4, and y is 1 to 5, provided that x+y is 2 to 7; and z is 1 to 5.