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。

FeTPPS是一种5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrin iron III chloride peroxynitrite的分解催化剂，在脊髓损伤的实验模型中具有明显的神经保护作用，能够降低脑组织炎症和损伤，抑制NO生成和凋亡，可用于研究创伤性脑损伤（TBI）。

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。

Hexacyclen是一种六氮杂环十八烷和18-冠-6的类似物，对Extracellular calcium-sensing receptor具有拮抗和阻断作用，EC50=20μM。Hexacyclen具有许多仲胺基团，是很好的电子供体，还具有嵌段共聚物的功能。