The azoreduction of phenylazo-2-naphthol (Sudan I), 5-(phenylazo)-6-hydroxynaphthalene-2-sulfonic acid (aniline subsidiary color of FD&C Yellow No. 6 (ANSC)), and phenylazophenol (Solvent Yellow 7 (SY7)) in skin during percutaneous absorption was measured and the contributions of cytosolic and microsomal reductions were characterized. By using a series of azo dyes with a common U-14C-labeled phenylazo moiety, percutaneous absorption and metabolism were measured in vitro in flow through diffusion cells with Sencar mouse, hairless guinea pig, and human skin. Azoreductase assays using subcellular fractions from skin of all species were used to examine intracellular rates and distribution for the series of dyes. The absorption of the lipophilic dyes Sudan I and SY7 from a finite surface dose of 5 ug/sq cm was extensive in all species. In mouse, 32.8 + or - 2.8% of the applied Sudan I Jose and 64.1 + or - 3.3% of the applied SY7 Jose were absorbed in 24 hr. In the hairless guinea pig, 57.6 + or - 5.9% of the applied Sudan I dose and 67.8 + or - 4.6% of the applied SY7 dose were absorbed in 24 hr. Human skin was least permeable, with 26.4 + or - 6.7% of the applied Sudan I Jose and 36.1 + or 4.5% of the applied SY7 dose absorbed in 24 hr. Sudan I and SY7 were extensively reduced in skin of all species during percutaneous absorption (29.5 and 26.5%, respectively, of the absorbed dose in human skin and greater than 50% of the applied Jose in other species). ANSC was the least absorbed, with 5% or less penetrating. SY7 was preferentially reduced in the skin cytosol of all species, whereas Sudan I was equally reduced in the skin cytosol and microsomal fractions. The site of azoreduction in the cell may affect the metabolic fate of the liberated arylamine. The extensive azoreduction observed during percutaneous absorption may modulate the toxicities of these compounds and must be considered when effective doses are determined for quantitative risk assessments from dermal exposures.
A study was made of the chemical structural requirements for binding to microsomal cytochrome p450 and enzymic reduction of the azo linkage in p-dimethylaminoazobenzene (DAB) and related azo dye carcinogens. Liver microsomes were prepared from male Wistar rats, some of which had been pretreated with microsomal enzyme inducers. Dimethylaminoazobenzene, its corresponding primary and secondary amines, and p-hydroxyazobenzene showed high substrate reactivity for reduction by microsomes. ... Active substrates showed type I (p-hydroxy derivative) or type 11 binding spectra, while inactive substrates showed only weak binding with microsomes. When two inactive compounds were incubated with microsomes under aerobic conditions, allowing preliminary hydroxylation to occur, there was marked facilitation of azoreduction. /It was/ concluded that p-substituted azobenzenes with electron donating groups facilitate azo dye reduction by rat liver microsomes, with good correlation between cytochrome p450 binding and substrate reactivity. Hydroxylation facilitates reduction of otherwise nonreactive compounds.
4-Phenylazophenol has known human metabolites that include (2S,3S,4S,5R)-3,4,5-trihydroxy-6-(4-phenyldiazenylphenoxy)oxane-2-carboxylic acid.
来源:NORMAN Suspect List Exchange
毒理性
致癌性证据
没有关于人类的数据。动物致癌性证据不足。总体评估:第3组:该物质对人类致癌性无法分类。
No data are available in humans. Inadequate evidence of carcinogenicity in animals. OVERALL EVALUATION: Group 3: The agent is not classifiable as to its carcinogenicity to humans.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌物分类
国际癌症研究机构致癌剂:4-羟基偶氮苯
IARC Carcinogenic Agent:4-Hydroxyazobenzene
来源:International Agency for Research on Cancer (IARC)
毒理性
致癌物分类
国际癌症研究机构(IARC)致癌物分类:第3组:对其对人类的致癌性无法分类
IARC Carcinogenic Classes:Group 3: Not classifiable as to its carcinogenicity to humans
来源:International Agency for Research on Cancer (IARC)
毒理性
致癌物分类
国际癌症研究机构专论集:第8卷:(1975年)一些芳香偶氮化合物
IARC Monographs:Volume 8: (1975) Some Aromatic Azo Compounds
来源:International Agency for Research on Cancer (IARC)
NINE ALBINO RATS WERE FED A DIET CONTAINING 4-HYDROXYAZOBENZENE (CONCN NOT GIVEN); 4/5 RATS DYING BETWEEN 159-284 DAYS DEVELOPED MULTIPLE PAPILLOMAS OF THE FORESTOMACH /NO REPORTED CONTROLS/.
DOSES OF 500 & 700 MG 4-HYDROXYAZOBENZENE, WHICH DID NOT PRODUCE TOXIC EFFECTS, WERE COMPLETELY ABSORBED FROM THE DIET OF RABBITS & WERE EXCRETED MAINLY IN THE URINE AS GLUCURONIDE.
Formation of asymmetric N-hydroxyaryl-N?-aryl(hetaryl)diazenes in the reaction of N-aryl(hetaryl)-N?-phosphoryldiazene-N-oxides with bases
摘要:
Aromatic and heterocyclic N'-phenoxyphosphoryldiazene N-oxides react with bases to give asymmetric N-hydroxyaryl-N'-aryl- and N-hydroxyaryl-N'-hetaryldiazenes.
The present application relates to encapsulates, compositions, products comprising such encapsulates, and processes for making and using such encapsulates. Such encapsulates comprise a core comprising a perfume and a shell that encapsulates said core, such encapsulates may optionally comprise a parametric balancing agent, such shell comprising one or more azobenzene moieties.
Accurate Prediction of Glucuronidation of Structurally Diverse Phenolics by Human UGT1A9 Using Combined Experimental and In Silico Approaches
作者:Baojian Wu、Xiaoqiang Wang、Shuxing Zhang、Ming Hu
DOI:10.1007/s11095-012-0666-z
日期:2012.6
Catalytic selectivity of human UGT1A9, an important membrane-bound enzyme catalyzing glucuronidation of xenobiotics, was determined experimentally using 145 phenolics and analyzed by 3D-QSAR methods. Catalytic efficiency of UGT1A9 was determined by kinetic profiling. Quantitative structure activity relationships were analyzed using CoMFA and CoMSIA techniques. Molecular alignment of substrate structures was made by superimposing the glucuronidation site and its adjacent aromatic ring to achieve maximal steric overlap. For a substrate with multiple active glucuronidation sites, each site was considered a separate substrate. 3D-QSAR analyses produced statistically reliable models with good predictive power (CoMFA: q2 = 0.548, r2 = 0.949, r pred 2 = 0.775; CoMSIA: q2 = 0.579, r2 = 0.876, r pred 2 = 0.700). Contour coefficient maps were applied to elucidate structural features among substrates that are responsible for selectivity differences. Contour coefficient maps were overlaid in the catalytic pocket of a homology model of UGT1A9, enabling identification of the UGT1A9 catalytic pocket with a high degree of confidence. CoMFA/CoMSIA models can predict substrate selectivity and in vitro clearance of UGT1A9. Our findings also provide a possible molecular basis for understanding UGT1A9 functions and substrate selectivity.
通过实验使用145种酚类化合物,并通过3D-QSAR方法分析,确定了人UGT1A9的催化选择性。UGT1A9是一种重要的膜结合酶,催化外源性物质的葡糖醛酸化反应。通过动力学分析确定了UGT1A9的催化效率。使用CoMFA和CoMSIA技术分析了定量结构活性关系。通过将葡糖醛酸化位点及其相邻的芳香环重叠,实现了底物结构的最大立体重叠。对于具有多个活性葡糖醛酸化位点的底物,每个位点被视为单独的底物。3D-QSAR分析产生了统计上可靠的模型,具有良好的预测能力(CoMFA:q2=0.548,r2=0.949,r pred 2=0.775;CoMSIA:q2=0.579,r2=0.876,r pred 2=0.700)。通过轮廓系数图阐明了底物中负责选择性差异的结构特征。将轮廓系数图叠加在UGT1A9的同源模型的催化口袋中,能够高度自信地识别UGT1A9的催化口袋。CoMFA/CoMSIA模型可以预测底物的选择性和UGT1A9的体外清除率。我们的发现还提供了理解UGT1A9功能和底物选择性的可能分子基础。
Unusual Reaction of Azoxybenzenes with<i>p</i>-Toluenesulfonic Acid in Acetic Anhydride
作者:Ichiro Shimao、Ken Fujimori、Shigeru Oae
DOI:10.1246/bcsj.55.1538
日期:1982.5
azoxybenzene with p-toluenesulfonic acid in aceticanhydride gave tosylates of 4- and 2-(phenylazo)phenols, and the corresponding acetates as by-product, besides azobenzene. However, a similar reaction of 4,4′-difluoroazoxybenzene gave 2-tosyloxy-4,4′-difluoroazobenzene as rearrangement product, besides 4-fluorophenyl tosylate and 4-fluorophenyl acetate. Meanwhile, the reaction of 4,4′-diacetoxyazoxybenzene
Studies on the azobenzene derivative based phasetransitions mostly rely on photoisomerization, which require a long time to spontaneously revert back. Here we show a photothermal-driven solid-to-liquid transition and fast reversion of azobenzene derivatives. Owing to the aggregation of suitably substituted azobenzenes, solid-to-liquid transitions can be induced by photothermal effects under irradiation
Flash vacuum pyrolysis of azo and nitrosophenols: new routes towards hydroxyarylnitrenes and their reactions
作者:Yehia A Ibrahim、Nouria A Al-Awadi、Kamini Kual
DOI:10.1016/s0040-4020(03)00863-9
日期:2003.7
Flashvacuumpyrolysis of phenylazonaphthols and nitrosonaphthols at 700°C and 0.02 Torr yielded quinoline, isoquinoline, indene and naphthols (and aniline only from the phenylazo derivatives). Similar FVP of p-nitroso and p-phenylazophenol gave pyridine. Also, FVP of phenanthraquinonemonophenylhydrazone and monooxime gave phenathridine and fluorenone. The formation of the heterocyclic system was assumed