In this work, we report the isolation and detailed functional characterization for the new non-ribosomally synthesized antibiotic 5812-A/C, which was derived from metabolites of Streptomyces roseoflavus INA-Ac-5812.According to its chemical structure, the studied 5812-A/C preliminary is composed of a cyclic peptide part covalently bounded with an arabinose residue.N-terminal amino acid sequencing of the native peptide has identified its partial structure of Leu-Asp-Gly-Ser-Gly and consisting of a Tyr residue that is supposed to have a two-component peptide nature for the molecule studied.However, the structural analysis of the antibiotic sofia barclay sexy complex derived from S.
roseoflavus INA-Ac-5812 is still ongoing.The mechanism of action of 5812-A/C was assessed in comparison with its most related analog, the lipopeptide antibiotic daptomycin, given the presence in both antimicrobials of an L-kynurenine amino acid residue.The inhibitory activity of 5812-A/C against Gram-positive bacteria including methicillin-resistant strain of Staphylococcus aureus was similar to daptomycin.The mechanism of action of 5812-A/C was associated with the disruption of membrane integrity, which differs in comparison with daptomycin and is most similar to the antimicrobial membrane-disturbing peptides.
However, 5812-A/C revlon colorstay lip liner plum demonstrated a calcium-dependent mode of action.In addition, unlike daptomycin, 5812-A/C was able to penetrate mature biofilms and inhibit the metabolic activity of embedded S.aureus cells.At the same time, 5812-A/C has no hemolytic activity toward erythrocyte, but possessed weak cytotoxic activity represented by heterochromatin condensation in human buccal epithelium cells.
The biological properties of the peptide 5812-A/C suggest its classification as a calcium-dependent antibiotic effective against a wide spectrum of Gram-positive pathogenic bacteria.