Definition: Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).
seglitide [ L 363586,L-363586,MK 678,MK-678,cyclo(MATTLVP),cyclo(N-Me-Ala-Tyr-Trp-Lys-Val-Phe),cyclo(N-methylalanyl-tyrosyl-tryptophyl-lysyl-valyl-phenylalanyl),seglitide acetate,seglitide monoacetate ] more potent than somatostatin for inhibition of insulin, glucagon & growth hormone release; used experimentally in treatment of Alzheimer's disease; somatostatin receptor antagonist