Toxicokinetic studies in rats given 14C-labelled cyromazine as single and repeated oral doses showed that the active substance is rapidly and almost completely absorbed from the gastrointestinal tract and distributed to all organs and tissues. ... Cyromazine was incompletely metabolized, essentially by methylation, hydroxylation or Ndealkylation. The major component present was cyromazine, which accounted for 71-72% of the radiolabel; a further 7% was attributable to melamine, 8-11% to hydroxy-cyromazine and methylcyromazine.
... A single oral dose of 0.025 mCi (0.38 mg) [14C]melamine /was administered/ to adult male Fischer 344 rats. ... Radioactivity in plasma or urine co-chromatographed with that of the dosing solution, indicating that melamine is not metabolized in the male Fischer 344 rat.
来源:Hazardous Substances Data Bank (HSDB)
代谢
非血尿是二甲基胺-单磷酸盐晶体排出的原因。
Crystalluria was due to excretion of dimelamine-monophosphate crystals.
来源:Hazardous Substances Data Bank (HSDB)
代谢
三聚氰胺不会被代谢,在给大鼠口服的研究中,它会迅速通过尿液排出体外。
Melamine is not metabolized and is rapidly eliminated via urine in a study with oral application to rats. (L1777)
IDENTIFICATION: Melamine is a monoclinic prismatic substance that is slightly soluble in water and ethanol. It is insoluble in diethyl ether. Melamine forms synthetic resins with formaldehyde. It is used in the manufacture of melamine resins, laminates, surface coating resins, plastic molding compounds, textile resins, bonding resins, gypsum melamine resin mixtures, orthopedic casts, rubber additives and paper products. HUMAN EXPOSURE: Occupational exposure to melamine may occur during its production and use in manufacture of synthetic resins with formaldehyde. ANIMAL STUDIES: Melamine was tested for its carcinogenicity by oral diet in mice and rats and for initiating activity by skin application in mice. No neoplasm related to treatment was observed after oral administration in mice. Male rats fed diets containing melamine developed transitional cell tumors in the urinary bladder, with one exception; all tumor bearing animals had bladder stones probably containing melamine. The incidence of urinary bladder hyperplasia associated with toxicity in male mice treated with melamine in the diet was observed. Groups of 20 male Fisher 344 rats, six weeks old were fed diets containing melamine with a purity of 99.4% with or without 10% NaCl for a total of 36 weeks and were sacrificed at week 40. Urinary bladder carcinomas were observed in all dose groups given melamine alone and melamine with NaCl. No carcinomas were observed in the melamine and NaCl groups. The incidences of papillomas were significantly decreased by NaCl. In contrast to the incidence of papillomas in the group given high dose melamine alone and in rats receiving high dose melamine and NaCl respectively, developed papillomas. Papillomas developed in rats receiving lower dose melamine alone. The occurrence of tumors correlated with calculus (melamine uric acid salt) formation and papillomatosis. Male and female Fisher 344 rats and B6C3F1 mice were fed melamine in the diet for 103 weeks. Twenty percent of the males at high dose and only 2% at the low dose and none of the controls had bladder stones. Seven of the eight urinary bladders with transitional cell carcinomas and three of the remaining 41 bladders without neoplasms had stones. There was statistically significant correlation between the bladder stones and bladder tumors. Fifty percent of a single oral dose of melamine was recovered in the urine of rats within 6 hr. After administration of a single dose of (14)-C-melamine to adult Fisher 344/N rats, 90% of the dose was excreted in the urine within the first 24 hr. Most of the radiolabel was concentrated in the kidney and bladder and negligible amounts were detected in exhaled air and feces. The radiolabelled material found in the plasma and urine indicated that melamine was not metabolized in rats. Melamine induced lambda prophage in Escherichia coli (WP2s-lambda) but did not induce reverse mutation in Salmonella typhimurium in presence or absence of an exogenous metabolic activation system . Sex linked recessive lethal mutations were not induced in Drosophila melanogaster. Melamine did not induce gene linked mutation in Salmonella typhimurium or sister chromatid exchange in Chinese hamster cells in vitro or micronuclei in mouse bone marrow in vivo. Melamine by oral administration has produced urinary bladder and ureteral carcinomas in male rats but only urinary hyperplasia in male mice. The occurrence of urinary tumors in male rats correlated strictly with calculus formation and exposure to higher doses. The dose dependence was confirmed by other studies in male rats in which concomitant administration of sodium chloride to increase urinary output resulted in a decreased tumor yield.
Melamine causes carcinomas of the urinary bladder at high doses (in male rats). Formation of bladder stones occurred and these calculi are necessary for the induction of tumours. Carcinomas are induced by continuous irritation of the bladder epithelium by the calculi, so that melamine acts only indirectly as a non-genotoxic carcinogen. (L1777)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌性证据
癌症分类:D组 不可归入人类致癌性类别
Cancer Classification: Group D Not Classifiable as to Human Carcinogenicity
Evaluation: There is inadequate evidence in humans for the carcinogenicity of melamine. There is sufficient evidence in experimental animals for the carcinogenicity of melamine under conditions in which it produces bladder calculi. Overall evaluation: In making the overall evaluation, the Working Group noted that a non-DNA reactive mechanism by which melamine produced urinary bladder tumors in male rats occurred only under conditions in which calculi were produced. Melamine is not classifiable as to its carcinogenicity to humans (Group 3).
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物:三聚氰胺
IARC Carcinogenic Agent:Melamine
来源:International Agency for Research on Cancer (IARC)
... A single oral dose of 0.025 mCi (0.38 mg) [14C]melamine /was administered/ to adult male Fischer 344 rats. Within the first 24 hr, 90% of the administered dose was excreted in the urine. Negligible radioactivity appeared in breath and feces. There was little difference in blood, liver or plasma concentrations of 14C, suggesting that melamine distributes in body water. The only organs showing radioactivity levels much higher than plasma were the kidney and bladder. The bladder level was by far the highest, a finding probably due either to back diffusion from urine or to contamination of bladder tissue with urine. Virtually no residual radioactivity was observed in tissues examined at 24 hr or later. The elimination-phase half-life calculated from plasma data, 2.7 hr, was in good agreement with the urinary-excretion half-life of 3.0 hr. The renal clearance of melamine was 2.5 mL/min.
... Following oral administration of 250 mg/kg melamine to rats, 50% of the mother compound was excreted with the urine within 6 hrs. ... Crystals found in the urine were composed of dimelamine monophosphate, amounting to nearly 20% of the administered dose. After feeding melamine to dogs, 60 - 86.5% of the mother compound was recovered in the urine within 24 hrs. ...
来源:Hazardous Substances Data Bank (HSDB)
吸收、分配和排泄
剂量为2.4克/千克会导致利尿,并随尿液排出微小的二甲基磷酸胺晶体。
Doses of 2.4 g/kg cause diuresis & elimination of fine crystals of dimelamine monophosphate in urine.
After administration of a single oral dose of 0.38 mg (14)C-melamine to adult male Fischer 344/N rats, 90% of the administered dose was excreted in the urine within the first 24 hours. Negligible radioactivity was detected in exhaled air and feces; and radioactivity was concentrated in the kidney and bladder. Virtually no residual radioactivity was observed in tissue after 24 hours or more. Chromatography of the radioactivity found in plasma or urine indicated that melamine is not metabolized in rats.
1.周国泰,化学危险品安全技术全书,化学工业出版社,1997 2.国家环保局有毒化学品管理办公室、北京化工研究院合编,化学品毒性法规环境数据手册,中国环境科学出版社.1992 3.Canadian Centre for Occupational Health and Safety,CHEMINFO Database.1998 4.Canadian Centre for Occupational Health and Safety, RTECS Database, 1989
Unsaturated Mo in Mo<sub>4</sub>O<sub>4</sub>N<sub>3</sub> for efficient catalytic transfer hydrogenation of nitrobenzene using stoichiometric hydrazine hydrate
作者:Shicheng Luo、Yu Long、Kun Liang、Jiaheng Qin、Yi Qiao、Jing Li、Guangxue Yang、Jiantai Ma
DOI:10.1039/d1gc02647j
日期:——
Transferhydrogenation of nitroarenes to the corresponding anilines using hydrazine hydrate and non-noble metal catalysts has already been widely studied. However, the toxicity resulting from excess hydrazine hydrate and the high reaction temperature limit its industrial application. Herein, a novel N-doped molybdenum oxide compound (Mo4O4N3) was in situ prepared from g-C3N4 and (NH4)6Mo7O24·4H2O (AHM)
已经广泛研究了使用水合肼和非贵金属催化剂将硝基芳烃氢化成相应的苯胺。然而,过量的水合肼导致的毒性和高反应温度限制了其工业应用。在此,一种新型的掺杂N氧化钼化合物(莫4 ø 4 Ñ 3)为在原位从GC制备3 Ñ 4和(NH 4)6沫7 ö 24 ·4H 2 O(AHM)。制备的 Mo 4 O 4 N 3使用化学计量摩尔比的水合肼(–NO 2 : N 2 H 4 ·H 2 O = 1: 1.5)在室温下放置 50 分钟,可以实现苯胺的 99% 产率。机理实验和表征技术表明,Mo 4 O 4 N 3中不饱和Mo的酸性位点可以有效地激活N 2 H 4分子,形成活性氢物种,用于硝基芳烃的催化转移加氢,而不会产生有害的NH 3。此外,Mo 4 O 4 N 3在无溶剂的大规模反应中仍表现出优异的催化性能。这项工作可能为芳胺生产提供一种可行且有效的策略。
(Cu/NCNTs): a new high temperature technique to prepare a recyclable nanocatalyst for four component pyridine derivative synthesis and nitroarenes reduction
with copper nanoparticles, have been prepared using a novel approach to the pre-existing methods. Their properties and characteristics have been studied using different techniques including UV-vis, XPS, TGA, ICP-AES, VSM, CHN, XRD, SEM-EDAX and TEM analysis. The Cu/NCNTs show nanocatalytic activity for the synthesis of four component pyridine derivatives and selectivereduction of nitroarenes to their
使用预先存在的方法的新颖方法,制备了进一步用铜纳米颗粒修饰的N掺杂碳纳米管(NCNT)。已使用不同技术研究了它们的性质和特性,包括紫外线可见,XPS,TGA,ICP-AES,VSM,CHN,XRD,SEM-EDAX和TEM分析。Cu / NCNT在环境温度条件下对合成四组分吡啶衍生物和将硝基芳烃选择性还原为相应的胺具有纳米催化活性。1 H NMR和13 C NMR用于确认合成转化的产物。我们还报告了一个新的吡啶衍生物,乙基6-(4,6-二氨基-1,3,5-三嗪-2-基氨基)-5-氰基-2-甲基-4-苯基吡啶-3-羧酸酯(5j) ,通过 在吡啶合成中使用三聚氰胺作为氮源。
Phosphine-Free Well-Defined Mn(I) Complex-Catalyzed Synthesis of Amine, Imine, and 2,3-Dihydro-1<i>H</i>-perimidine via Hydrogen Autotransfer or Acceptorless Dehydrogenative Coupling of Amine and Alcohol
report the synthesis of amines/imines directly from alcohol and amines via hydrogen autotransfer or acceptorless dehydrogenation catalyzed by well-defined phosphine-free Mn complexes. Both imines and amines can be obtained from the same set of alcohols and amines using the same catalyst, only by tuning the reaction conditions. The amount and nature of the base are found to be a highly important aspect for
Synthesis of functionalized chromene and spirochromenes using l -proline-melamine as highly efficient and recyclable homogeneous catalyst at room temperature
commercially cheap l-proline and melamine for the synthesis of chromenes and spirochromenes (spirooxindoles) via multicomponent reactions at room temperature. Systematic studies were conducted in order to achieve desired reactivity and recyclability of the catalyst using various α-amino acids and aromatic amines as donor-acceptor pairs. Among the screened combinations, l-proline and melamine (3:1 ratio;
A metal-free heterogeneous photocatalyst for the selective oxidative cleavage of CC bonds in aryl olefins <i>via</i> harvesting direct solar energy
作者:Yu Zhang、Nareh Hatami、Niklas Simon Lange、Emanuel Ronge、Waldemar Schilling、Christian Jooss、Shoubhik Das
DOI:10.1039/d0gc01187h
日期:——
transition metal-free) to avoid further leaching in the final products. This is for sure a big challenge to an organic chemist and to the pharmaceutical industries! To make this feasible, a mild and efficient protocol has been developed using polymericcarbonnitrides (PCN) as metal-free heterogeneous photocatalysts to convert various olefins into the corresponding carbonyls. Later, this catalyst has been
C C键的选择性裂解对于合成含羰基的精细化学品和药物非常重要。新型方法,例如臭氧分解反应,Lemieux-Johnson氧化反应等。已经存在。与此平行,还发现了使用均相催化剂的催化方法。考虑到非均相催化剂的各种优点,例如可循环性和稳定性,已将几种基于过渡金属的非均相催化剂用于该反应。但是,制药行业更喜欢使用不含金属的催化剂(尤其是不含过渡金属的催化剂),以避免最终产品中进一步浸出。对于有机化学家和制药行业来说,这无疑是一个巨大的挑战!为了使之可行,已经开发了一种温和而有效的方案,使用聚合碳氮化物(PCN)作为无金属的非均相光催化剂,将各种烯烃转化为相应的羰基。后来,该催化剂已被用于使用直接太阳能的克级合成药物中。详细的机械研究揭示了氧气,催化剂和光源的实际作用。