quorum sensing-in-7

Quorum sensing-IN-7 (compound HSL 4) is an effective quorum sensing (QS) inhibitor. It interacts with the binding sites Leu 72 and Gln 95 of CviR. As an antimicrobial agent, Quorum sensing-IN-7 effectively inhibits the production of homoserine lactones (HSLs) and biofilms in C. violaceum at concentrations ranging from 0.25-1 mg mL.

N-(3-hydroxy-7-cis tetradecenoyl)-L-Homoserine lactone is a long-chain N-acyl-homoserine lactone (AHL) produced by some Gram-negative bacteria and is involved in quorum sensing. Quorum sensing enables bacteria to change gene expression based on cues from nearby bacteria and from eukaryotic hosts about nutrients, environmental conditions, or threats. Due to the benefit of quorum sensing for bacterial survival, quorum sensing molecules are potential targets for controlling bacterial infections. In mouse and human leukocyte immunoassays using LPS-stimulated macrophages, N-(3-hydroxy-7-cis tetradecenoyl)-L-homoserine lactone did not have an effect on cytokine or antibody production.

Quorum sensing is a regulatory process used by bacteria for controlling gene expression in response to increasing cell density.[1] This regulatory process manifests itself with a variety of phenotypes including biofilm formation and virulence factor production.[2] Coordinated gene expression is achieved by the production, release, and detection of small diffusible signal molecules called autoinducers. The N-acylated homoserine lactones (AHLs) comprise one such class of autoinducers, each of which generally consists of a fatty acid coupled with homoserine lactone (HSL). AHLs vary in acyl group length (C4-C18), in the substitution of C3 (hydrogen, hydroxyl, or oxo group) and in the presence or absence of one or more carbon-carbon double bonds in the fatty acid chain. These differences confer signal specificity through the affinity of transcriptional regulators of the LuxR family.[3] C16:1-Δ9-(L)-HSL is a long-chain AHL that functions as a quorum sensing signaling molecule in strains of S. meliloti.[4],[5],[6],[7] Regulating bacterial quorum sensing signaling can be used to inhibit pathogenesis and thus, represents a new approach to antimicrobial therapy in the treatment of infectious diseases.[8] Reference：[1]. González, J.E., and Keshavan, N.D. Messing with bacterial quorum sensing. Microbiol. Mol. Biol. Rev. 70(4), 859-875 (2006).[2]. Gould, T.A., Herman, J., Krank, J., et al. Specificity of acyl-homoserine lactone syntheses examined by mass spectrometry. J. Bacteriol. 188(2), 773-783 (2006).[3]. Penalver, C.G.N., Morin, D., Cantet, F., et al. Methylobacterium extorquens AM1 produces a novel type of acyl-homoserine lactone with a double unsaturated side chain under methylotrophic growth conditions. FEBS Lett. 580(2), 561-567 (2006).[4]. Teplitski, M., Eberhard, A., Gronquist, M.R., et al. Chemical identification of N-acyl homoserine lactone quorum-sensing signals produced by Sinorhizobium meliloti strains in defined medium. Archives of Microbiology 180, 494-497 (2003).[5]. Gao, M., Chen, H., Eberhard, A., et al. sinI- and expR-dependent quorum sensing in Sinorhizobium meliloti. Journal of Bacteriology 187(23), 7931-7944 (2005).[6]. Marketon, M.M., Glenn, S.A., Eberhard, A., et al. Quorum sensing controls exopolysaccharide production in Sinorhizobium meliloti. Journal of Bacteriology 185(1), 325-331 (2003).[7]. Marketon, M., Gronquist, M.R., Eberhard, A., et al. Characterization of the Sinorhizobium meliloti sinR/sinI locus and the production of novel N-Acyl homoserine lactones. Journal of Bacteriology 184(20), 5686-5695 (2002).[8]. Cegelski, L., Marshall, G.R., Eldridge, G.R., et al. The biology and future prospects of antivirulence therapies. Nat. Rev. Microbiol. 6(1), 17-27 (2008).

Quorum sensing is a regulatory system used by bacteria for controlling gene expression in response to increasing cell density.[1] This regulatory process manifests itself with a variety of phenotypes including biofilm formation and virulence factor production.[2] Coordinated gene expression is achieved by the production, release, and detection of small diffusible signal molecules called autoinducers. The N-acylated homoserine lactones (AHLs) comprise one such class of autoinducers, each of which generally consists of a fatty acid coupled with homoserine lactone (HSL). Regulation of bacterial quorum sensing signaling systems to inhibit pathogenesis represents a new approach to antimicrobial therapy in the treatment of infectious diseases.[3] AHLs vary in acyl group length (C4-C18), in the substitution of C3 (hydrogen, hydroxyl, or oxo group), and in the presence or absence of one or more carbon-carbon double bonds in the fatty acid chain. These differences confer signal specificity through the affinity of transcriptional regulators of the LuxR family.[4] C16-HSL is one of a number of lipophilic, long acyl side-chain bearing AHLs, including its monounsaturated analog C16:1-(L)-HSL, produced by the LuxI AHL synthase homolog SinI involved in quorum-sensing signaling in S. meliloti, a nitrogen-fixing bacterial symbiont of certain legumes.[5],[6] C16-HSL is the most abundant AHL produced by the proteobacterium R. capsulatus and activates genetic exchange between R. capsulatus cells.[7] N-Hexadecanoyl-L-homoserine lactone and other hydrophobic AHLs tend to localize in relatively lipophilic cellular environments of bacteria and cannot diffuse freely through the cell membrane. The long-chain N-acylhomoserine lactones may be exported from cells by efflux pumps or may be transported between communicating cells by way of extracellular outer membrane vesicles.[8],[9]Reference:[1]. González, J.E., and Keshavan, N.D. Messing with bacterial quorum sensing Microbiol. Mol. Biol. Rev. 70(4), 859-875 (2006).[2]. Gould, T.A., Herman, J., Krank, J., et al. Specificity of acyl-homoserine lactone syntheses examined by mass spectrometry Journal of Bacteriology 188(2), 773-783 (2006).[3]. Cegelski, L., Marshall, G.R., Eldridge, G.R., et al. The biology and future prospects of antivirulence therapies Nature Reviews.Microbiology 6(1), 17-27 (2008).[4]. Penalver, C.G.N., Morin, D., Cantet, F., et al. Methylobacterium extorquens AM1 produces a novel type of acyl-homoserine lactone with a double unsaturated side chain under methylotrophic growth conditions FEBS Letters 580, 561-567 (2006).[5]. Gao, M., Chen, H., Eberhard, A., et al. sinI- and expR-dependent quorum sensing in Sinorhizobium meliloti Journal of Bacteriology 187(23), 7931-7944 (2005).[6]. Teplitski, M., Eberhard, A., Gronquist, M.R., et al. Chemical identification of N-acyl homoserine lactone quorum-sensing signals produced by Sinorhizobium meliloti strains in defined medium Archives of Microbiology 180, 494-497 (2003).[7]. Schaefer, A.L., Taylor, T.A., Beatty, J.T., et al. Long-chain acyl-homoserine lactone quorum-sensing regulation of Rhodobacter capsulatus gene transfer agent production Journal of Bacteriology 184(23), 6515-6521 (2002).[8]. Pearson, J.P., Van Delden, C., and Iglewski, B.H. Active efflux and diffusion are involved in transport of Pseudomonas aeruginosa cell-to-cell signals Journal of Bacteriology 181(4), 1203-1210 (1999).[9]. Mashburn-Warren, L., and Whiteley, M. Special delivery: Vesicle trafficking in prokaryotes Molecular Microbiology 61(4), 839-846 (2006).

Nifuroxazide-d4 is intended for use as an internal standard for the quantification of nifuroxazide by GC- or LC-MS. Nifuroxazide is a nitrofuran antibiotic. It is active against strains of the enteropathogenic bacteria C. jejuni, Salmonella, Y. enterocolitica, Shigella, and E. coli. It inhibits quorum sensing and virulence factor production in P. aeruginosa. Nifuroxazide inhibits STAT3 activity in a reporter assay and decreases viability of U266 and INA-6 myeloma cells, which have constitutive STAT3 phosphorylation, with EC50 values of approximately 4.5 µM for both. It also decreases viability, migration, and invasion of, and induces apoptosis in, MCF-7, 4T1, and MDA-MB-231 breast cancer cells. Nifuroxazide reduces tumor growth and prevents pulmonary metastasis in a 4T1 murine mammary carcinoma model. It also reduces diarrhea, weight loss, and colon inflammation in a rat model of acetic acid-induced ulcerative colitis.

LasR antagonist 1 (Compound 7), with an IC50 of 0.4 μM, is an effective antagonist of LasR that modulates quorum sensing (QS) in the opportunistic pathogen Pseudomonas aeruginosa [1].