铬离子 | 18540-29-9

• 分子结构分类: 无机化合物 - 均相金属化合物 - 均相过渡金属化合物
• 中文名称: 铬离子
• 中文别名: 六价铬
• 英文名称: Chromium(6+)
• CAS: 18540-29-9
• 化学式: Cr+6
• 分子量: 51.996
• InChiKey: JOPOVCBBYLSVDA-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.0
• 重原子数：
  1
• 可旋转键数：
  0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

ADMET

代谢

铬通过口腔、吸入或皮肤接触被吸收，并分布到几乎所有组织中，肾脏和肝脏中浓度最高。骨骼也是一个主要的储存场所，并可能导致长期保留。六价铬与硫酸盐和铬酸盐的相似性使其能够通过硫酸盐转运机制进入细胞。在细胞内，六价铬首先被还原为五价铬，然后通过许多物质，包括抗坏血酸、谷胱甘肽和烟酸腺嘌呤二核苷酸还原为三价铬。铬几乎完全通过尿液排出体外。（A12, L16）

Chromium is absorbed from oral, inhalation, or dermal exposure and distributes to nearly all tissues, with the highest concentrations found in kidney and liver. Bone is also a major storage site and may contribute to long-term retention. Hexavalent chromium's similarity to sulfate and chromate allow it to be transported into cells via sulfate transport mechanisms. Inside the cell, hexavalent chromium is reduced first to pentavalent chromium, then to trivalent chromium by many substances including ascorbate, glutathione, and nicotinamide adenine dinucleotide. Chromium is almost entirely excreted with the urine. (A12, L16)

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 毒性总结

六价铬的致癌作用是由其代谢物五价铬和三价铬引起的。DNA损伤可能是由细胞内存在的过氧化氢分子在五价铬再氧化过程中产生的羟基自由基引起的。三价铬还可能形成与肽、蛋白质和DNA的复合物，导致DNA-蛋白质交联、DNA链断裂、DNA-DNA链间交联、铬-DNA加合物、染色体畸变和细胞信号通路改变。已经证明，它通过过度刺激细胞调节通路，并通过激活某些丝裂原活化蛋白激酶增加过氧化氢水平来诱导致癌作用。它还可以通过将组蛋白去乙酰化酶1-DNA甲基转移酶1复合物与CYP1A1启动子染色质交联，抑制组蛋白修饰，引起转录抑制。铬可能通过修饰金属调节转录因子1，导致抑制锌诱导的金属硫蛋白转录，从而增加其自身的毒性。(A12, L16, A34, A35, A36)

Hexavalent chromium's carcinogenic effects are caused by its metabolites, pentavalent and trivalent chromium. The DNA damage may be caused by hydroxyl radicals produced during reoxidation of pentavalent chromium by hydrogen peroxide molecules present in the cell. Trivalent chromium may also form complexes with peptides, proteins, and DNA, resulting in DNA-protein crosslinks, DNA strand breaks, DNA-DNA interstrand crosslinks, chromium-DNA adducts, chromosomal aberrations and alterations in cellular signaling pathways. It has been shown to induce carcinogenesis by overstimulating cellular regulatory pathways and increasing peroxide levels by activating certain mitogen-activated protein kinases. It can also cause transcriptional repression by cross-linking histone deacetylase 1-DNA methyltransferase 1 complexes to CYP1A1 promoter chromatin, inhibiting histone modification. Chromium may increase its own toxicity by modifying metal regulatory transcription factor 1, causing the inhibition of zinc-induced metallothionein transcription. (A12, L16, A34, A35, A36)

来源:Toxin and Toxin Target Database (T3DB)

毒理性

• 致癌物分类

国际癌症研究机构致癌物：铬（VI）化合物

IARC Carcinogenic Agent:Chromium (VI) compounds

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1组：对人类致癌

IARC Carcinogenic Classes:Group 1: Carcinogenic 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著：补充卷7：致癌性的总体评估：更新国际癌症研究机构专著第1卷至第42卷，1987年；440页；ISBN 92-832-1411-0（已绝版） 卷49：（1990年）铬、镍和焊接 卷100C：（2012年）砷、金属、纤维和尘埃

IARC Monographs:Volume Sup 7: Overall Evaluations of Carcinogenicity: An Updating of IARC Monographs Volumes 1 to 42, 1987; 440 pages; ISBN 92-832-1411-0 (out of print) Volume 49: (1990) Chromium, Nickel and Welding Volume 100C: (2012) Arsenic, Metals, Fibres, and Dusts

来源:International Agency for Research on Cancer (IARC)

毒理性

• 致癌物分类

1, 对人类致癌。

1, carcinogenic to humans. (L135)

来源:Toxin and Toxin Target Database (T3DB)

安全信息

• 职业暴露限值：
  TWA: None mg/m3

反应信息

• 作为反应物：
  描述：

  铬离子 、 dipotassium;oxido-(oxido(dioxo)chromio)oxy-dioxochromium 、 溶剂黄146 以 水 为溶剂， 生成 chromium (VI) acetate
  参考文献：
  名称：

  Novel metal-micelle asbestos and treatment of asbestos and other

  摘要：

  硅酸盐矿物，包括石棉纤维，通过在硅酸盐上形成金属胶束聚合物涂层而变得不那么有害。通过将硅酸盐矿物（如石棉）与金属弱碱-强酸水离子体系或金属强碱-弱酸离子体系接触，可以在硅酸盐上形成金属胶束聚合物涂层。在这些体系中，金属选自锰、铬、钴、铁、铜、铝和这些金属的混合物。用这些体系处理石棉纤维的产物对生物细胞的刺激性较小，而且在大多数技术应用中可以代替石棉纤维，因为它具有与石棉纤维基本相同的物理和化学特性。

  公开号：

  US04401636A1
• 作为试剂：
  描述：

  (2RS,4S)-4,8-dimethyl-7-nonen-2-ol 、 Jones' reagent 、 硫酸 、 sodium hydrogensulfite 在 chromium (VI) trioxide 、 铬离子 ice 、 petroleum ether 、 Brine 、 碳酸氢钠 作用下， 以 水 、 丙酮 为溶剂， 反应 6.0h， 以to obtain 194 g of (4S)-4,8-dimethyl-7-nonen-2-one (b.p.: 63° C./133 Pa, [α]D24=−10.7° (c=1.00, EtOH))的产率得到(4S)-4,8-dimethyl-7-nonen-2-one
  参考文献：
  名称：

  Isomer composition containing optically active ethyl trans-2,2,6-trimethylcyclohexylcarboxylate and fragrance composition containing the isomer composition

  摘要：

  本发明涉及一种几何异构体组成物，其气味和化学耐性均优异，适用于含有强碱性化学物质或强酸性化学物质的基材料，可以抑制材料暴露在光线下时的时间劣化和颜色变化，并具有高度可口和独特的果香花香味。该组成物是通过混合93至99重量％的由式-1表示的光学活性乙基顺-2,2,6-三甲基环己基羧酸乙酯或其混合物和7至1重量％的由式-2表示的光学活性乙基顺-2,2,6-三甲基环己基羧酸乙酯或其混合物制成的。

  公开号：

  US20030207789A1

文献信息

• Permeability contrast correction employing propionate-sequestered
  申请人：Phillips Petroleum Company

  公开号：US04636572A1

  公开（公告）日：1987-01-13

  A process for preparing clear green chromium(III) propionate solutions which comprises admixing such as propionic acid with water, a chromium(VI) source such as dichromate, adding thereto a nitrite, such as sodium nitrite, to reduce the chromium(VI) to chromium(III), in the presence of excess acid, preferably propionic acid, optionally combined with additional acid such as muriatic acid, to produce a stable solution useful with polymers, such as partially hydrolyzed acrylamide-based polymers, in permeability contrast correction procedures for high permeability streaks in oil field treatments.

  一种制备清晰的绿色铬（III）丙酸盐溶液的方法，包括将丙酸与水混合，加入铬（VI）源，例如重铬酸盐，然后加入亚硝酸盐，例如亚硝酸钠，以还原铬（VI）为铬（III），在过量酸的存在下进行，最好是丙酸，可选择性地与其他酸，例如盐酸，结合使用，以产生稳定的溶液，用于与聚合物，例如部分水解的丙烯酰胺基聚合物一起，在渗透率对比校正程序中使用，用于油田处理中高渗透率条纹的处理。
• Interactions of chromium with microorganisms and plants
  作者：Carlos Cervantes、Jesús Campos-García、Silvia Devars、Félix Gutiérrez-Corona、Herminia Loza-Tavera、Juan Carlos Torres-Guzmán、Rafael Moreno-Sánchez

  DOI：10.1111/j.1574-6976.2001.tb00581.x

  日期：2001.5

  Chromium is a highly toxic non-essential metal for microorganisms and plants. Due to its widespread industrial use, chromium (Cr) has become a serious pollutant in diverse environmental settings. The hexavalent form of the metal, Cr(VI), is considered a more toxic species than the relatively innocuous and less mobile Cr(III) form. The presence of Cr in the environment has selected microbial and plant variants able to tolerate high levels of Cr compounds. The diverse Cr-resistance mechanisms displayed by microorganisms, and probably by plants, include biosorption, diminished accumulation, precipitation, reduction of Cr(VI) to Cr(III), and chromate efflux. Some of these systems have been proposed as potential biotechnological tools for the bioremediation of Cr pollution. In this review we summarize the interactions of bacteria, algae, fungi and plants with Cr and its compounds.

  铬是一种对微生物和植物具有高度毒性的非必需金属。由于铬（Cr）在工业上的广泛应用，它已成为各种环境中的严重污染物。六价铬（Cr(VI)）被认为比相对无害且流动性较差的三价铬（Cr(III)）更具毒性。环境中铬的存在选择出了能够耐受高浓度铬化合物的微生物和植物变种。微生物（可能还有植物）表现出多种抗铬机制，包括生物吸附、减少积累、沉淀、将六价铬还原为三价铬以及铬酸盐外排。其中一些系统已被提议作为生物修复铬污染的潜在生物技术工具。在这篇综述中，我们总结了细菌、藻类、真菌和植物与铬及其化合物的相互作用。
• Chromate-Reducing Properties of Soluble Flavoproteins from <i>Pseudomonas putida</i> and <i>Escherichia coli</i>
  作者：D. F. Ackerley、C. F. Gonzalez、C. H. Park、R. Blake、M. Keyhan、A. Matin

  DOI：10.1128/aem.70.2.873-882.2004

  日期：2004.2

  Cr(VI) (chromate) is a toxic, soluble environmental contaminant. Bacteria can reduce chromate to the insoluble and less toxic Cr(III), and thus chromate bioremediation is of interest. Genetic and protein engineering of suitable enzymes can improve bacterial bioremediation. Many bacterial enzymes catalyze one-electron reduction of chromate, generating Cr(V), which redox cycles, generating excessive reactive oxygen species (ROS). Such enzymes are not appropriate for bioremediation, as they harm the bacteria and their primary end product is not Cr(III). In this work, the chromate reductase activities of two electrophoretically pure soluble bacterial flavoproteins—ChrR (from Pseudomonas putida ) and YieF (from Escherichia coli )—were examined. Both are dimers and reduce chromate efficiently to Cr(III) ( k _cat / K _m = ∼2 × 10 ⁴ M ⁻¹  · s ⁻¹ ). The ChrR dimer generated a flavin semiquinone during chromate reduction and transferred >25% of the NADH electrons to ROS. However, the semiquinone was formed transiently and ROS diminished with time. Thus, ChrR probably generates Cr(V), but only transiently. Studies with mutants showed that ChrR protects against chromate toxicity; this is possibly because it preempts chromate reduction by the cellular one-electron reducers, thereby minimizing ROS generation. ChrR is thus a suitable enzyme for further studies. During chromate reduction by YieF, no flavin semiquinone was generated and only 25% of the NADH electrons were transferred to ROS. The YieF dimer may therefore be an obligatory four-electron chromate reducer which in one step transfers three electrons to chromate and one to molecular oxygen. As a mutant lacking this enzyme could not be obtained, the role of YieF in chromate protection could not be directly explored. The results nevertheless suggest that YieF may be an even more suitable candidate for further studies than ChrR.

  摘要 六价铬（铬酸盐）是一种有毒的可溶性环境污染物。细菌可将铬酸盐还原为不溶性且毒性较低的铬(III)，因此铬酸盐生物修复技术备受关注。合适酶的基因和蛋白质工程可以改善细菌的生物修复能力。许多细菌酶催化铬酸盐的单电子还原，生成铬（V），铬（V）进行氧化还原循环，产生过多的活性氧（ROS）。这类酶不适合用于生物修复，因为它们会伤害细菌，而且其主要最终产物不是铬（III）。在这项工作中，两种电泳纯的可溶性细菌黄蛋白--铬酸还原酶（来自假单胞菌 Putida）和铬酸还原酶（来自假单胞菌 Pseudomonas Putida）--的铬酸还原酶活性得到了验证。 假单胞菌 ）和 YieF（来自 大肠杆菌 )的活性进行了研究。这两种蛋白都是二聚体，能有效地将铬酸盐还原成 Cr(III) ( k cat / K m = ∼2 × 10 4 M -1 - s -1 ).ChrR 二聚体在铬酸盐还原过程中产生了黄素半醌，并将 25% 的 NADH 电子转移到 ROS 中。不过，半醌是瞬时形成的，ROS 会随着时间的推移而减少。因此，ChrR 可能会产生 Cr（V），但只是短暂的。对突变体的研究表明，ChrR 能防止铬酸盐中毒；这可能是因为它能阻止细胞中的单电子还原剂还原铬酸盐，从而最大限度地减少 ROS 的产生。因此，ChrR 是一种适合进一步研究的酶。在 YieF 还原铬酸盐的过程中，没有黄素半醌生成，只有 25% 的 NADH 电子转移到 ROS 上。因此，YieF 二聚体可能是一种强制性的四电子铬酸盐还原酶，它在一个步骤中将三个电子转移到铬酸盐，一个电子转移到分子氧。由于无法获得缺乏这种酶的突变体，因此无法直接探讨 YieF 在铬酸盐保护中的作用。不过研究结果表明，YieF 可能比 ChrR 更适合进一步研究。
• Analysis of Novel Soluble Chromate and Uranyl Reductases and Generation of an Improved Enzyme by Directed Evolution
  作者：Y. Barak、D. F. Ackerley、C. J. Dodge、L. Banwari、C. Alex、A. J. Francis、A. Matin

  DOI：10.1128/aem.01334-06

  日期：2006.11

  Most polluted sites contain mixed waste. This is especially true of the U.S. Department of Energy (DOE) waste sites which hold a complex mixture of heavy metals, radionuclides, and organic solvents. In such environments enzymes that can remediate multiple pollutants are advantageous. We report here evolution of an enzyme, ChrR6 (formerly referred to as Y6), which shows a markedly enhanced capacity for remediating two of the most serious and prevalent DOE contaminants, chromate and uranyl. ChrR6 is a soluble enzyme and reduces chromate and uranyl intracellularly. Thus, the reduced product is at least partially sequestered and nucleated, minimizing the chances of reoxidation. Only one amino acid change, ^Tyr 128 ^Asn , was responsible for the observed improvement. We show here that ChrR6 makes Pseudomonas putida and Escherichia coli more efficient agents for bioremediation if the cellular permeability barrier to the metals is decreased.

  摘要 大多数污染场地都含有混合废物。美国能源部（DOE）的废物处理场尤其如此，这些废物含有重金属、放射性核素和有机溶剂的复杂混合物。在这种环境下，能够修复多种污染物的酶具有优势。我们在此报告了一种酶 ChrR6（以前称为 Y6）的进化情况，它对两种最严重、最普遍的 DOE 污染物（铬酸盐和铀酰）的修复能力明显增强。ChrR6 是一种可溶性酶，能在细胞内还原铬酸盐和铀酰。因此，还原产物至少部分被螯合和成核，最大限度地减少了再氧化的机会。只有一个氨基酸发生变化、 酪氨酸 128 Asn 是导致所观察到的改进的原因。我们在此表明，ChrR6 使 假单胞菌 和 大肠杆菌 更有效地进行生物修复。
• Crystal Structure of ChrR—A Quinone Reductase with the Capacity to Reduce Chromate
  作者：Subramaniam Eswaramoorthy、Sébastien Poulain、Rainer Hienerwadel、Nicolas Bremond、Matthew D. Sylvester、Yian-Biao Zhang、Catherine Berthomieu、Daniel Van Der Lelie、A. Matin

  DOI：10.1371/journal.pone.0036017

  日期：——

  The Escherichia coli ChrR enzyme is an obligatory two-electron quinone reductase that has many applications, such as in chromate bioremediation. Its crystal structure, solved at 2.2 Å resolution, shows that it belongs to the flavodoxin superfamily in which flavin mononucleotide (FMN) is firmly anchored to the protein. ChrR crystallized as a tetramer, and size exclusion chromatography showed that this is the oligomeric form that catalyzes chromate reduction. Within the tetramer, the dimers interact by a pair of two hydrogen bond networks, each involving Tyr128 and Glu146 of one dimer and Arg125 and Tyr85 of the other; the latter extends to one of the redox FMN cofactors. Changes in each of these amino acids enhanced chromate reductase activity of the enzyme, showing that this network is centrally involved in chromate reduction.

  大肠杆菌ChrR酶是一种必需的两电子醌还原酶，具有多种应用，例如在铬酸盐生物修复中的应用。其晶体结构以2.2 Å的分辨率解析，显示它属于黄素超家族，其中黄素单核苷酸（FMN）牢固地锚定在蛋白质上。ChrR以四聚体的形式结晶，尺寸排阻色谱显示这是催化铬酸盐还原的寡聚体形式。在四聚体中，二聚体通过一对氢键网络相互作用，每个网络涉及一个二聚体的Tyr128和Glu146以及另一个二聚体的Arg125和Tyr85；后者延伸至氧化还原FMN辅因子之一。这些氨基酸中的每一个的变化都会增强铬酸盐还原酶的活性，表明该网络在铬酸盐还原中起着核心作用。