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).
iturin A [ iturin A(L) ] from various strains of Bacillus subtilis; active component in bacillomycin B, R & eumycin; the lipid moiety is a mixture of amino long-chain saturated fatty acids & the peptide moiety consists of 7 a