Manganese is absorbed mainly via ingestion, but can also be inhaled. It binds to alpha-2-macroglobulin, albumin, or transferrin in the plasma and is distributed to the brain and all other mammalian tissues, though it tends to accumulate more in the liver, pancreas, and kidney. Manganese is capable of existing in a number of oxidation states and is believed to undergo changes in oxidation state within the body. Manganese oxidation state can influence tissue toxicokinetic behavior, and possibly toxicity. Manganese is excreted primarily in the faeces. (L228)
Manganese is a cellular toxicant that can impair transport systems, enzyme activities, and receptor functions. It primarily targets the central nervous system, particularily the globus pallidus of the basal ganglia. It is believed that the manganese ion, Mn(II), enhances the autoxidation or turnover of various intracellular catecholamines, leading to increased production of free radicals, reactive oxygen species, and other cytotoxic metabolites, along with a depletion of cellular antioxidant defense mechanisms, leading to oxidative damage and selective destruction of dopaminergic neurons. In addition to dopamine, manganese is thought to perturbations other neurotransmitters, such as GABA and glutamate. In order to produce oxidative damage, manganese must first overwhelm the antioxidant enzyme manganese superoxide dismutase. The neurotoxicity of Mn(II) has also been linked to its ability to substitute for Ca(II) under physiological conditions. It can enter mitochondria via the calcium uniporter and inhibit mitochondrial oxidative phosphorylation. It may also inhibit the efflux of Ca(II), which can result in a loss of mitochondrial membrane integrity. Mn(II) has been shown to inhibit mitochondrial aconitase activity to a significant level, altering amino acid metabolism and cellular iron homeostasis. (L228)
来源:Toxin and Toxin Target Database (T3DB)
毒理性
致癌物分类
对人类不具有致癌性(未被国际癌症研究机构IARC列名)。
No indication of carcinogenicity to humans (not listed by IARC).
Manganese mainly affects the nervous system and may cause behavioral changes and other nervous system effects, which include movements that may become slow and clumsy. This combination of symptoms when sufficiently severe is referred to as “manganism”. (L228)
Manganese mainly affects the nervous system and may cause behavioral changes and other nervous system effects, which include movements that may become slow and clumsy. This combination of symptoms when sufficiently severe is referred to as “manganism”. (L228)
between the MnO¥¥¥H N linkage with formation of NH4NO3 and CuMn2O4-type mixed oxides instead of stepwise deammoniation, even below 100. The thermal deammoniation of 1 in aqueous solution led, instead of to hydrated copper(2) bis(permanganate), to the formation of NH4MnO4 (2). Since the temperature of the thermal deammoniation of 1 is lower than the decomposition temperature of the permanganate ion, the
b), Istva ¬ n Sajo ¬ a ), Ja ¬nos Kristo ¬fc Tetraamminecopper(2) bis(permanganate) ((Cu(NH3)4)(MnO4)2; 1)水溶液和固相。通过IR和拉曼方法检测了络合物阳离子的氨配体与高锰酸根离子的O原子之间存在H键相互作用。1 的固相热脱氨导致 MnO¥¥¥HN 键之间发生不寻常的分子内氧化还原反应,形成 NH4NO3 和 CuMn2O4 型混合氧化物,而不是逐步脱氨,甚至低于 100。1 在水溶液中的热脱氨导致形成 NH4 (2),而不是水合双高锰酸铜 (2)。由于1的热脱氨温度低于高锰酸根离子的分解温度,
Three Reagents In One: Ammonium Permanganate In The Oxidation Of Benzyl Alcohol
作者:László Kotai、Béla Kazinczy、Ágnes Keszler、Sándor Holly、István Gács、Kalyan K. Banerji
DOI:10.1515/znb-2001-0816
日期:2001.8.1
The oxidation or consecutive ammoxidation reaction of benzyl alcohol with solid ammonium permanganate was studied. The first oxidation step leads to the formation of benzaldehyde, ammonia, and MnO2. The MnO2 is present in the system in a colloidal form which facilitates the reaction between aldehyde and ammonia, and this latter reaction then yields benzonitrile. All these products are formed in a heterogeneous system under relatively mild conditions. The yield of benzaldehyde has an optimum at room temperature and increases with increasing reaction time. At higher temperature (e.g. 80 °C) benzonitrile is formed together with minor amounts of benzyl benzoate
Studies on the Chemistry of Tetraamminezinc(II) Dipermanganate ([Zn(NH<sub>3</sub>)<sub>4</sub>](MnO<sub>4</sub>)<sub>2</sub>): Low-Temperature Synthesis of the Manganese Zinc Oxide (ZnMn<sub>2</sub>O<sub>4</sub>) Catalyst Precursor
作者:István E. Sajó、László Kótai、Gábor Keresztury、István Gács、György Pokol、János Kristóf、Bojan Soptrayanov、Vladimir M. Petrusevski、Daniel Timpu、Pradeep K. Sharma
DOI:10.1002/hlca.200890180
日期:2008.9
Tetraamminezinc(II) dipermanganate ([Zn(NH3)4](MnO4)2; 1) was prepared, and its structure was elucidated with XRD-Rietveld-refinement and vibrational-spectroscopy methods. Compound 1 has a cubic lattice consisting of a 3D H-bound network built from blocks formed by four MnO anions and four [Zn(NH3)4]2+ cations. The other four MnO anions are located in a crystallographically different environment, namely