Gramicidin

Gramicidin (Gramicidine) is an antimicrobial peptide. Gramicidin dimers form ion channel-like pores in the cell membranes and organelles of bacterial and animal cells, allowing inorganic monovalent ions, such as potassium and sodium ions, to pass freely through the pores by diffusion, disrupting the important ionic gradient between membranes and thus killing the cells by various actions. Gramicidin is effective against Gram-positive bacteria such as Bacillus subtilis and Staphylococcus aureus, but is not as effective against Gram-negative bacteria such as Escherichia coli.

Gramicidin C, a naturally occurring polypeptide antibiotic, is isolated from B. brevis var. G.B.

Gramicidin S (Gramicidin Soviet), a cationic cyclic peptide antibiotic, disrupts the membrane integrity of both Gram-positive and Gram-negative bacteria and inhibits cytochrome bd quinol oxidase [1].

Gramicidin S 2HCl, is an antibiotic. At concentrations of 40-80 μg/mL, GS can reduce planktonic cell numbers within 20-40 minutes. For established biofilms, it effectively kills cells at concentrations of 100-200 μg/mL without regrowth. This anti-biofilm effect results from peptide transmembrane transport and complexation with intracellular nucleotides (including the alarmone ppGpp). GS demonstrates wide-ranging activity against biofilm-forming, drug-resistant infections caused by E. faecalis, proving its efficacy in endodontic treatment. The successful treatment of persistent infections in two volunteer cases further confirms GS's potent therapeutic performance. These studies indicate that GS can be applied in certifying compounds used in endodontics.

Gramicidin A is a peptide antibiotic isolated from B. brevis.Gramicidin A is a highly hydrophobic channel-forming ion carrier that forms monovalent cation-permeable channels in artificial membranes.Gramicidin A induces the degradation of hypoxia-inducible factor 1 alpha (HIF-1 alpha) and reduces the growth of a mouse xenograft model of human renal cell carcinoma. Gramicidin A has antibacterial, antimalarial and hemolytic activities.

Gramicidin B, a nonribosomal peptide, exhibits antibiotic properties [1].

Gramicidin A (TFA) is a peptide component of Gramicidin, an antibiotic mixture originally isolated from B. brevis. It is a highly hydrophobic channel-forming ion carrier that creates monovalent cation-permeable channels in artificial membranes. Additionally, Gramicidin A (TFA) induces the degradation of hypoxia-inducible factor 1α (HIF-1α).

(-)-Epicatechin gallate ((-)-Epicatechin 3-O-gallate) is one of the catechin isomers and a potent antioxidant that can modulate a wide range of membrane proteins. Its bilayer-modifying potency was tested using gramicidin A (gA) channels as probes. All the catechins alter gA channel function and modify bilayer properties, with a 500-fold range in potency. The gallate group causes current block, as evident by brief downward current transitions.

Tyrothricin is a natural polypeptide antibiotic, a mixture of gramicidin and tyrocidine, capable of disrupting the cell membranes of Gram-positive bacteria and applicable for treating skin infections.

NRPSs-IN-1 (Compound 7) serves as an inhibitor of non-ribosomal peptide synthetases (NRPSs) and is capable of penetrating cells. It effectively inhibits Gramicidin S synthetase A (GrsA) with a Kd of 16.6 nM.

Pradimicin A derivative 26 exhibits antifungal, antiviral, and antiparasitic properties by attaching to d-mannose (Man)-rich glycans in pathogenic organisms [1].

(-)-Epicatechin gallate (Standard) is a reference standard for research and analysis in studies involving (-)-Epicatechin gallate. (-)-Epicatechin gallate ((-)-Epicatechin 3-O-gallate) is one of the catechin isomers and a potent antioxidant that can modulate a wide range of membrane proteins. Its bilayer-modifying potency was tested using gramicidin A (gA) channels as probes. All the catechins alter gA channel function and modify bilayer properties, with a 500-fold range in potency. The gallate group causes current block, as evident by brief downward current transitions.