In a rat liver prepn, KB-1585 ... , a new orally well-absorbed ester of ampicillin, ... was rapidly hydrolyzed to ampicillin and diacetyl which was further metabolized to 2,3-butanediol via acetoin.
来源:Hazardous Substances Data Bank (HSDB)
代谢
鸽子肝脏二乙酰还原酶催化二乙酰转化为乙偶姻。
Pigeon-liver diacetyl reductase catalyzed the conversion of diacetyl to acetoin.
The metabolism of diacetyl (2,3-butanedione), acetoin (3-hydroxy-2-butanone), and 2,3-butanediol, which are metabolites of acetaldehyde was quantitatively investigated using rat liver homogenate, liver perfusion, and in vivo experiments. Diacetyl and acetoin were reduced to 2,3-butanediol in these experiments, but acetoin and 2,3-butanediol were scarcely oxidized to diacetyl, indicating that the reduction reaction to 2,3-butanediol from diacetyl occurs actively in rat liver. The formation of acetoin from diacetyl required either NADH or NADPH as a reductant, while the reduction of acetoin to 2,3-butanediol required NADH. Acetoin and 2,3-butanediol were more readily accumulated than diacetyl in brain tissue.
IDENTIFICATION AND USE: Diacetyl (DA) is a yellow liquid. It is used as synthetic flavoring substance and adjuvant. Diacetyl has been widely used as a chemical modifier of proteins, combining with arginine residues. HUMAN EXPOSURE AND TOXICITY: Diacetyl is a diketone flavoring agent that is commonly employed for buttery taste as well as other purposes. Industrial exposure to flavoring agents, particularly diacetyl, has recently been associated with bronchiolitis obliterans, a severe respiratory illness producing fibrosis and obstruction of the small airways. This has been most commonly reported in the microwave popcorn production industry, but it has occurred elsewhere. In addition to bronchiolitis obliterans, spirometry abnormalities (fixed airflow obstruction) and respiratory symptoms have been associated with exposure. A direct effect on the respiratory epithelium with the disorganized fibrotic repair appears most likely as the underlying mechanism. Current data suggest that diacetyl is the agent responsible, although it is possible that diacetyl is simply a marker for another causative agent. Workers at the microwave popcorn company experienced normal rates of all-cause mortality but higher rates of chronic obstructive pulmonary disease-associated mortality, especially workers employed before the company reduced diacetyl exposure. According to case reports, lung disease could also arise in the consumers of diacetyl-containing popcorn. ANIMAL STUDIES: Male mice were exposed by inhalation to 200 or 400 ppm DA 6 hr/day for 5 days. 400 ppm caused deaths and acute necrotizing rhinitis, laryngitis and bronchitis (proximal large bronchi). Exposure to 200 ppm caused a few deaths and acute necrotizing rhinitis and erosive or necrotizing laryngitis in all mice. There were no lung or bronchiolar lesions in the DA exposed mice. Chronic bronchitis, laryngitis, and rhinitis were present after 2 and 4 weeks of exposure. In rats diacetyl inhalation increases substance P levels in sensory nerves of airway epithelium. Because substance P release in airways promotes inflammation and activation of sensory nerves mediates reflexes, neural changes may contribute to flavorings-related lung disease pathogenesis. When given i.p. to mice once weekly for 24 weeks, diacetyl (1.70 or 8.40 mg/kg [0.0197 or 0.0976 mmol/kg]) did not induce any lung tumors. Groups of hamsters, mice, and rats were given a solution containing 90% diacetyl by gavage on days 6-10 of gestation for hamsters and days 6-15 of gestation for mice and rats. The doses for all species were 16, 74, 345, or 1600 mg/kg bw per day. No effects were seen on maternal survival, weight, or reproductive parameters or on fetal survival or microscopic appearance of external, skeletal, or soft tissues. Diacetyl induced mitotic chromosome loss in Saccharomyces cerevisiae in the presence of propionitrile. In several bacterial assays, diacetyl generally showed mutagenic activity in Salmonella typhimurium strains TA100, 102, and 104 with and without metabolic activation but none against strain TA98. Conflicting results were obtained in Escherichia coli strain WP2 uvra, but nonmutagenicity was demonstrated in the SOS-chromotest using E. coli PQ37. Diacetyl was also negative in a micronucleus test using mouse bone marrow cells.
Diacetyl is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌性证据
A4:不能分类为人类致癌物。
A4: Not classifiable as a human carcinogen.
来源:Hazardous Substances Data Bank (HSDB)
毒理性
致癌物分类
无致癌性迹象(未被国际癌症研究机构列名)。
No indication of carcinogenicity (not listed by IARC). (L135)
Acute exposure to cholinesterase inhibitors can cause a cholinergic crisis characterized by severe nausea/vomiting, salivation, sweating, bradycardia, hypotension, collapse, and convulsions. Increasing muscle weakness is a possibility and may result in death if respiratory muscles are involved. Accumulation of ACh at motor nerves causes overstimulation of nicotinic expression at the neuromuscular junction. When this occurs symptoms such as muscle weakness, fatigue, muscle cramps, fasciculation, and paralysis can be seen. When there is an accumulation of ACh at autonomic ganglia this causes overstimulation of nicotinic expression in the sympathetic system. Symptoms associated with this are hypertension, and hypoglycemia. Overstimulation of nicotinic acetylcholine receptors in the central nervous system, due to accumulation of ACh, results in anxiety, headache, convulsions, ataxia, depression of respiration and circulation, tremor, general weakness, and potentially coma. When there is expression of muscarinic overstimulation due to excess acetylcholine at muscarinic acetylcholine receptors symptoms of visual disturbances, tightness in chest, wheezing due to bronchoconstriction, increased bronchial secretions, increased salivation, lacrimation, sweating, peristalsis, and urination can occur. Certain reproductive effects in fertility, growth, and development for males and females have been linked specifically to organophosphate pesticide exposure. Most of the research on reproductive effects has been conducted on farmers working with pesticides and insecticdes in rural areas. In females menstrual cycle disturbances, longer pregnancies, spontaneous abortions, stillbirths, and some developmental effects in offspring have been linked to organophosphate pesticide exposure. Prenatal exposure has been linked to impaired fetal growth and development. Neurotoxic effects have also been linked to poisoning with OP pesticides causing four neurotoxic effects in humans: cholinergic syndrome, intermediate syndrome, organophosphate-induced delayed polyneuropathy (OPIDP), and chronic organophosphate-induced neuropsychiatric disorder (COPIND). These syndromes result after acute and chronic exposure to OP pesticides.
2,3-Butanedione (BD) is a reactive diketone in artificial butter flavors that is thought to cause bronchiolitis obliterans in workers in microwave popcorn manufacturing. Bronchiolitis obliterans is generally not diagnosed until irreversible damage has occurred; therefore a biomarker of early exposure is needed. The potential systemic uptake of BD from inhalation exposure has not been evaluated. The objective here was to evaluate the systemic exposure of BD and binding to hemoglobin and albumin. [(14)C]BD was administered to male Harlan Sprague Dawley rats (100 mg/kg, intratracheal instillation) and B6C3F1/N mice (157 mg/kg, oropharyngeal aspiration). Blood and plasma was collected 24 hr after administration and analyzed for (14)C content. At 24 hr, 0.88 +/- 0.07% of the administered dose was in rat blood, 0.66 +/- 0.06% in rat plasma, 0.38 +/- 0.13% in mouse blood and 0.17 +/- 0.05% in mouse plasma. Albumin binding in rats was 269 +/- 24.2 ng equiv./mg, which accounts for 38% of the radioactivity in plasma. In mice, binding was 85.0 +/- 22.3 ng equiv./mg albumin, which accounts for 51% of the radioactivity in plasma. The binding to hemoglobin in rats was 38.2 +/- 17.6 ng equiv./mg, and to globin was 29.1 +/- 3.96 ng equiv./mg. In mice, the binding to hemoglobin was 16.2 +/- 9.0 ng equiv./mg. The site(s) of adduction on hemoglobin and albumin was investigated by mass spectrometry. In rat globin, arginine adducts were detected at R-30 and R-104 of the beta chain in vitro and in vivo. In rat albumin, adducts were detected in vitro on R-219/221, R-360, and R-368, and in vivo on a variety of arginine residues. This study demonstrated that BD enters the systemic circulation and reacts with arginine on hemoglobin and albumin. These results indicate that hemoglobin and albumin adducts may be useful as biomarkers of BD exposure in humans.
When administered to male Fischer 344 rats via intragastric gavage, a single dose of radiolabeled [(14)C]diacetyl (1.58, 15.8, or 158 mg/kg [0.0184, 0.184, or 1.84 mmol/kg]) resulted in excretion of 82.0, 72.7, and 54.3% of the administered doses, respectively, as carbon dioxide at 72 hours. In urine, the excreted amounts were 6.86, 15.7, and 34.1%, respectively. At all tested levels, total excretion of radioactivity in urine, feces, and expired breath accounted for 86-87% of the dose recovered within 24 hours. In normal rat liver mitochondria, diacetyl uncoupled oxidative phosphorylation, totally eliminated respiratory control with substrates, and partially eliminated it with succinate.[Integrated Laboratory Systems, Inc.; Chemical Information Review Document for Artificial Butter Flavoring and Constituents Diacetyl [CAS No. 431-03-8] and Acetoin
... The goal of this study was to develop a physiologically based pharmacokinetic model for inspired vapor dosimetry and to apply the model to diacetyl. The respiratory tract was modeled as a series of airways: nose, trachea, main bronchi, large bronchi, small bronchi, bronchioles, and alveoli with tissue dimensions obtained from the literature. Airborne vapor was allowed to absorb (or desorb) from tissues based on mass transfer coefficients. Transfer of vapor within tissues was based on molecular diffusivity with direct reaction with tissue substrates and/or metabolism being allowed in each tissue compartment. In vitro studies were performed to provide measures of diacetyl metabolism kinetics and direct reaction rates allowing for the development of a model with no unassigned variables. Respiratory tract uptake of halothane, acetone, ethanol and diacetyl was measured in male F344 rat to obtain data for model validation. The human model was validated against published values for inspired vapor uptake. For both the human and rat models, a close concordance of model estimates with experimental measurements was observed, validating the model. The model estimates that limited amounts of inspired diacetyl penetrate to the bronchioles of the rat (<2%), whereas in the lightly exercising human, 24% penetration to the bronchioles is estimated. Bronchiolar tissue concentrations of diacetyl in the human are estimated to exceed those in the rat by 40-fold. These inhalation dosimetric differences may contribute to the human-rat differences in diacetyl-induced airway injury.
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
在良性条件下通过直接自由基-自由基交叉偶联来构建C(sp 3)-N键是一种理想但具有挑战性的方法。在此,通过镍/光氧化还原双重催化,以简明,温和且无氧化剂的方式将烷基和and基自由基交叉偶联以建立脂族C–N键。在该协议中,成功地采用了单电子转移策略,分别从磺酰基叠氮化物/叠氮基甲酸酯和烷基三氟硼酸酯生成N-和C-中心的自由基。然而,光催化剂诱导的三重态-三重态能量转移机制可能不适用于该反应。激发的光催化剂(Ru II / * Ru II / Ru III / Ru II的氧化猝灭途径))结合可能的Ni I / Ni II / Ni III / Ni I催化循环,基于协同实验和计算研究,提出了镍/光氧化还原双催化C(sp 3)–N键形成的方法。
Condensation reactions between diacetyl and α-branched primary alkylamines under mild and neutral conditions provided a mixture of 2,5-dimethylbenzoquinone(alkylimines), 2,5-dimethylbenzoquinone(bis-alkyldiimines), and N,N′-dialkyl-2,5-dimethylbenzene-1,4-diamines, which were efficiently separated as pure products by column chromatography. Both 2,5-dimethylbenzoquinone(alkylimines) and 2,5-dimethylbenzoquinone(bis-alkyldiimines) underwent an interchange of the alkylimino group when treated with anilines, followed by reductive aromatization, to provide diarylamines and 1,4-dianilinobenzenes, respectively. Evaluation was also made of the reactivity and selectivity of these compounds in the presence of anilines, thiophenols and alkylhalides.
Oxidative Release of Copper from Pharmacologic Copper Bis(thiosemicarbazonato) Compounds
作者:John J. Sirois、Lillian Padgitt-Cobb、Marissa A. Gallegos、Joseph S. Beckman、Christopher M. Beaudry、James K. Hurst
DOI:10.1021/acs.inorgchem.8b00853
日期:2018.8.6
2-Pyridylazoresorcinol complexation was used to demonstrate that Cu(II) release by reaction with peroxynitrite species involved rate-limiting homolysis of the peroxy O–O bond to generate secondary oxidizing radicals (NO2•, •OH, and CO3•–). Because the potentials for CuII(btsc) oxidation and reduction are ligand-dependent, varying by as much as 200 mV, it is clearly advantageous in designing therapeutic methodologies
从铜-双-硫代嘧啶铜氮杂铜络合物向细胞内递送治疗性或分析性铜的机制通常涉及内源性还原剂将单电子还原为Cu(I)类似物的机制,从而使金属离子不稳定且与bis--不牢固地配位。硫半脲(btsc)配体。但是,本文所述的电化学和光谱研究表明,Cu II(btsc)和Zn II ATSM(btsc =二乙酰基-双(4-甲基硫代半碳氮杂))复合物的单电子氧化在生理氧化剂范围内发生,导致还存在未被认可的铜释放的氧化途径。H 2 O 2氧化Cu II(btsc)由髓过氧化物酶或辣根过氧化物酶,HOCl和牛磺酸氯胺(它们主要是由MPO催化反应在活化的中性粒细胞中产生的氯化剂)以及过氧化亚硝酸盐类(ONOOH,ONOOCO 2 –)催化的被证明。与还原不同,氧化反应通过不可逆的配体氧化进行,最终释放出Cu(II)。2-吡啶基偶氮间苯二酚络合物用于证明通过与过氧亚硝酸盐类物质反应释放Cu(II)涉及限速过氧O-
Radical-Trapping Antioxidant Activity of Copper and Nickel Bis(Thiosemicarbazone) Complexes Underlies Their Potency as Inhibitors of Ferroptotic Cell Death
作者:Omkar Zilka、Jia-Fei Poon、Derek A. Pratt
DOI:10.1021/jacs.1c08254
日期:2021.11.17
inhibitor of (phospho)lipid peroxidation. In THF autoxidations, CuATSM reacts with THF-derived peroxyl radicals with kinh = 2.2 × 106 M–1 s–1─roughly 10-fold greater than α-tocopherol (α-TOH), Nature’s best RTA. Mechanistic studies reveal no H/D kinetic isotope effects and a lack of rate-suppressing effects from H-bonding interactions, implying a different mechanism from α-TOH and other canonical RTAs, which
在此我们证明了铜 (II)-二乙酰-双 ( N 4 -甲基氨基硫脲) (CuATSM) 是治疗 ALS 和帕金森病的临床候选药物,是一种高效的自由基捕获抗氧化剂 (RTA) 和 (phospho) 的抑制剂脂质过氧化。在 THF 自动氧化中,CuATSM 与 THF 衍生的过氧自由基反应,k inh = 2.2 × 10 6 M –1 s –1─大约是自然界最好的 RTA α-生育酚 (α-TOH) 的 10 倍。机理研究表明,没有 H/D 动力学同位素效应,并且缺乏 H 键相互作用的速率抑制效应,这意味着与 α-TOH 和其他典型 RTA 的机制不同,后者通过 H 原子转移 (HAT) 反应。对于相应的 Ni 2+络合物和 Cu 2+和 Ni 2+的络合物,观察到类似的反应性与其他双(氨基硫脲)配体。计算证实了限速 HAT 不能解释观察到的 RTA 活性的实验发现,而是表明可逆地向双(氨