Patent ID: 7345144

Claim:
A synthetic cyclic pentapeptide or hexapeptide of the structural formula: wherein: R 1 is H, NH 2 , or R 2 is —C(═O)—NH— or —NH—C(═O)—; R 3a and R 3b 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 4 is —NH 2 or —NH(C═NH)NH 2 ; R 5 is 1- or 2-naphthyl or 3-indolyl, optionally with one or two ring substituents, and when one or both ring substituents are present, are the same or different and independently hydroxyl, halogen, alkyl, or aryl groups attached directly or through an ether linkage; R 6 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 aliphatic moiety with a terminal amino group; x is 1 to 4, and y is 1 to 5, provided that x+y is 2 to 7; and z is 2 to 5.