6-nitrogen

6-Azathymine 是胸腺嘧啶的 6-氮类似物，是 D-3-氨基异丁酸酯-丙酮酸氨基转移酶抑制剂，具有抗菌和抗病毒活性，可抑制DNA 的生物合成。

3-Hydroxykynurenamine, also known as 3-Hydroxy-L-kynurenamine or 3-HKA, is a biogenic amine produced via an alternative pathway of tryptophan metabolism. In vitro, 3-HKA has an anti-inflammatory profile by inhibiting the IFN-γ mediated STAT1 NF-κΒ pathway in both mouse and human dendritic cells (DCs) with a consequent decrease in the release of pro-inflammatory chemokines and cytokines, most notably TNF, IL-6, and IL12p70. 3-HKA has protective effects in an experimental mouse model of psoriasis by decreasing skin thickness, erythema, scaling and fissuring, reducing TNF, IL-1β, IFN-γ, and IL-17 production, and inhibiting generation of effector CD8+ T cells. Similarly, in a mouse model of nephrotoxic nephritis, besides reducing inflammatory cytokines, 3-HKA improves proteinuria and serum urea nitrogen, overall ameliorating immune-mediated glomerulonephritis and renal dysfunction.This compound is unstable in powder form and other related salt forms are recommended.

Hesperin (6-MSITC) 是从橙皮中分离得到的黄酮化合物，是植物中的昼夜节律去烯化酶，抑制 3T3-L1 和 RAW264.7 细胞中脂质积累和活性氧和活性氮的产生。

Peroxynitrite is a highly reactive nitrogen species formed from the reaction of nitric oxide (NO) and superoxide.[1] FeTPPS is a ferric porphyrin complex that causes the decomposition of peroxynitrite by catalytic isomerization to produce nitrate both in vitro and in vivo. The conversion of this reactive nitrogen species to nitrate results in cytoprotection (EC50 = 5 µM). [2][3] FeTPPS does not complex with NO and does not alter superoxide directly. It is commonly used to elucidate the roles of peroxynitrite in oxidative stress, cell damage, and intracellular signaling. [4][5][6]

AAPH is a water-soluble azo compound which is used extensively as a free radical generator, often in the study of lipid peroxidation and the characterization of antioxidants.[1],[2],[3],[4] Decomposition of AAPH produces molecular nitrogen and 2 carbon radicals. The carbon radicals may combine to produce stable products or react with molecular oxygen to give peroxyl radicals. The half-life of AAPH is about 175 hours (37°C at neutral pH), making the rate of free radical generation essentially constant during the first several hours in solution.[5] While AAPH may be used effectively for lipid peroxidation in aqueous dispersions of fatty acids, other radical generators may be better suited for peroxidation studies in lipid micelles or membranes.[6],[7]

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).

Neobavaisoflavone 是一种从Psoralea corylifolia 的种子中分离出来的类黄酮。它具有抗炎，抗癌和抗氧化的作用。它在中至高浓度下可抑制 DNA 聚合酶，也可抑制血小板聚集。

Indoxyl sulfate-d5 is intended for use as an internal standard for the quantification of indoxyl sulfate by GC- or LC-MS. Indoxyl sulfate is a uremic toxin and a metabolite of tryptophan. It is formed via sulfation of indole, an intermediate generated from tryptophan by intestinal bacteria, by the sulfotransferase (SULT) isoform 1A1 variant 2 (SULT1A1*2) in the liver. Indoxyl sulfate activates the aryl hydrocarbon receptor (AhR) in HepG2 40 6 hepatoma cells (EC50 = 12.1 nM in a reporter assay). It also inhibits the organic anion transporter (OAT) isoforms OAT1 and OAT3 (Kis = 34.2 and 74.4 µM, respectively for the rat transporters) in S2 proximal tubule cells. Indoxyl sulfate (0.2 and 1 mM) increases superoxide anion and nitric oxide levels in isolated human mononuclear blood cells. It increases serum creatinine and blood urea nitrogen (BUN) levels in the 5 6 nephrectomized rat model of chronic renal failure when administered at a dose of 50 mg kg.

C-2′-Decoumaroylaloeresin G (化合物8)为一种色酮糖苷，源自芦荟属植物。

Pap12-6是一种从蝶类P. xuthus幼虫中发现的papiliocin十二个N-端氨基酸衍生的抗菌肽。它对包括E. coli、P. aeruginosa和S. syphimurium在内的八种革兰氏阴性细菌（MIC50s = 4-8 µM）以及革兰氏阳性细菌S. aureus、耐甲氧西林的S. aureus 3126（MRSA-3126）、B. subtilis和S. epidermidis（MIC50s = 4-8 µM）具有活性，但在25 µM浓度下不影响人类红细胞、小鼠RAW 264.7巨噬细胞、人类HaCaT角质形成细胞或人类HEK293肾细胞的活性。Pap12-6在4和8 µM浓度下可引起E. coli的膜去极化。Pap12-6（10 µM）预处理可降低LPS刺激的RAW 264.7巨噬细胞中一氧化氮（NO2-）、Tnf-α和Il-6的分泌水平。在体内，Pap12-6（10 mg/kg）可以提高感染E. coli的小鼠的存活率，并且在剂量为1 mg/kg时减少感染E. coli小鼠的肺、肝和肾中菌落形成单位（CFUs）的数量。Pap12-6（1 mg/kg）在E. coli诱导的败血症小鼠模型中降低血清天门冬氨酸转氨酶（AST）和丙氨酸转氨酶（ALT）水平及血尿素氮水平。