2-hydroxy-1,4-benzoquinone anion

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 2-hydroxy-1,4-benzoquinone anion
• 英文别名: 3,6-Dioxocyclohexa-1,4-dien-1-olate
• 化学式: C₆H₃O₃
• 分子量: 123.088
• InChiKey: GPLIMIJPIZGPIF-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  0.8
• 重原子数：
  9
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.0
• 拓扑面积：
  57.2
• 氢给体数：
  0
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  2-hydroxy-1,4-benzoquinone anion 、 氢(+1)阳离子 、 NADH 生成 1,2,4-苯三酚 、 nicotinamide adenine dinucleotide
  参考文献：
  名称：

  Identification and Characterization of Catabolicpara-Nitrophenol 4-Monooxygenase andpara-Benzoquinone Reductase fromPseudomonassp. Strain WBC-3

  摘要：

  摘要假单胞菌 WBC-3 株利用对硝基苯酚（PNP）作为唯一的碳、氮和能量来源。为了确定参与这种利用的基因，我们克隆并测序了一个 12.7 kb 的片段，其中包含 NAD(P)H:quinone 氧化还原酶基因的保守区。在该片段推导出的 13 个开放阅读框的产物中，PnpA 与假单胞菌 U 的 3- 羟基苯乙酸酯羟化酶的大分子部分有 24% 的相同性，而 PnpB 与大肠杆菌的 NAD（P）H：醌氧化还原酶有 58% 的相同性。经凝胶过滤测定，PnpA 和 PnpB 分别为单体和二聚体。PnpA 是一种依赖于黄素腺嘌呤二核苷酸的单组分 PNP 4-单加氧酶，在 NADPH 存在下可将 PNP 转化为 Topara-苯醌。PnpB 是一种依赖于黄素单核苷酸和 NADPH 的对苯醌还原酶，可催化对苯醌还原为对苯二酚。PnpB 可增强 PnpA 的活性，遗传分析表明，PnpA 和 PnpB 在菌株 WBC-3 的 PNP 矿化过程中都起着至关重要的作用。此外，pnpAB 的下一个基因簇与荧光假单胞菌 ACB 中负责对苯二酚降解（hapCDEF）的基因簇（M. J. Moonen, N. M. Kamerbeek, A. H. Westphal, S. A. Boeren, D. B. Janssen, M. W. Fraaije, and W. J. van Berkel, J. Bacteriol.:5190-5198，2008），表明参与 PNP 降解的基因之间存在物理联系。

  DOI：

  10.1128/jb.01566-08
• 作为产物：
  描述：

  2-Hydroxy-1,4-benzosemichinon 在 对苯醌 作用下， 生成 4-hydroxycyclohexa-2,5-dien-1-one, sodium salt 、 2-hydroxy-1,4-benzoquinone anion
  参考文献：
  名称：

  OH自由基与苯醌在水溶液中的反应。脉冲放射分解研究

  摘要：

  通过在N 2 O饱和的水溶液中进行脉冲辐射分解可生成羟基自由基。它们在中性溶液中添加到1,4-苯醌BQ（k 3  = 6.6×10 9 dm 3 mol –1 s –1通过与硫氰酸盐竞争）导致光吸收的累积，该吸收在波长大约为20时表现出不同的速率330和> 400 nm。在330 nm处，堆积速率与苯醌浓度成正比，其速率常数与竞争获得的值（k 3）一致。在更长的波长处，它变得不受苯醌浓度的影响而超过4×10 –4 mol dm –3（k 6  = 6.9×10 5 s –1）。在ns时间范围内的动力学分析表明，初生的苯醌-OH加合物自由基1发生快速（k 4  = 2.5×10 6 s –1）酮-烯醇互变异构，生成2,4-二羟基苯氧基自由基2。为支持该提议的反应，自由基2 [p K a（2）≈4.9±0.2]是通过在酸性或N 3中用˙OH对1,2,4-三羟基苯进行单电子氧化而独立生成的˙采取

  DOI：

  10.1039/a708772a

文献信息

• Novel Pathway for Conversion of Chlorohydroxyquinol to Maleylacetate in <i>Burkholderia cepacia</i> AC1100
  作者：Olga Zaborina、Dayna L. Daubaras、Anna Zago、Luying Xun、Katsuhiko Saido、Thomas Klem、Dejan Nikolic、A. M. Chakrabarty

  DOI：10.1128/jb.180.17.4667-4675.1998

  日期：1998.9

  Burkholderia cepacia AC1100 metabolizes 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) via formation of 5-chlorohydroxyquinol (5-CHQ), hydroxyquinol (HQ), maleylacetate, and β-oxoadipate. The step(s) leading to the dechlorination of 5-CHQ to HQ has remained unidentified. We demonstrate that a dechlorinating enzyme, TftG, catalyzes the conversion of 5-CHQ to hydroxybenzoquinone, which is then reduced to HQ by a hydroxybenzoquinone reductase (HBQ reductase). HQ is subsequently converted to maleylacetate by hydroxyquinol 1,2-dioxygenase (HQDO). All three enzymes were purified. We demonstrate specific product formation by colorimetric assay and mass spectrometry when 5-CHQ is treated successively with the three enzymes: TftG, TftG plus HBQ reductase, and TftG plus HBQ reductase plus HQDO. This study delineates the complete enzymatic pathway for the degradation of 5-CHQ to maleylacetate.

  摘要 伯克霍尔德氏菌 AC1100 可通过生成 5-氯羟基对苯二酚（5-CHQ）、羟基对苯二酚（HQ）、马来乙酸酯和 β-氧代己二酸酯来代谢 2,4,5-三氯苯氧乙酸（2,4,5-T）。导致 5-CHQ 脱氯为 HQ 的步骤仍未确定。我们证明，一种脱氯酶 TftG 催化 5-CHQ 转化为羟基苯醌，然后被羟基苯醌还原酶（HBQ 还原酶）还原为 HQ。HQ 随后被羟基苯醌 1,2-二氧酶（HQDO）转化为马来乙酸酯。这三种酶均已纯化。我们通过比色法和质谱法证明了 5-CHQ 经三种酶连续处理后形成的特定产物：TftG、TftG 加 HBQ 还原酶和 TftG 加 HBQ 还原酶加 HQDO。这项研究描述了 5-CHQ 降解为马来乙酸酯的完整酶解途径。
• A Two-Component Monooxygenase Catalyzes Both the Hydroxylation of <i>p</i> -Nitrophenol and the Oxidative Release of Nitrite from 4-Nitrocatechol in <i>Bacillus sphaericus</i> JS905
  作者：Venkateswarlu Kadiyala、Jim C. Spain

  DOI：10.1128/aem.64.7.2479-2484.1998

  日期：1998.7

  Bacteria that metabolize p -nitrophenol (PNP) oxidize the substrate to 3-ketoadipic acid via either hydroquinone or 1,2,4-trihydroxybenzene (THB); however, initial steps in the pathway for PNP biodegradation via THB are unclear. The product of initial hydroxylation of PNP could be either 4-nitrocatechol or 4-nitroresorcinol. Here we describe the complete pathway for aerobic PNP degradation by Bacillus sphaericus JS905 that was isolated by selective enrichment from an agricultural soil in India. Washed cells of PNP-grown JS905 released nitrite in stoichiometric amounts from PNP and 4-nitrocatechol. Experiments with extracts obtained from PNP-grown cells revealed that the initial reaction is a hydroxylation of PNP to yield 4-nitrocatechol. 4-Nitrocatechol is subsequently oxidized to THB with the concomitant removal of the nitro group as nitrite. The enzyme that catalyzed the two sequential monooxygenations of PNP was partially purified and separated into two components by anion-exchange chromatography and size exclusion chromatography. Both components were required for NADH-dependent oxidative release of nitrite from PNP or 4-nitrocatechol. One of the components was identified as a reductase based on its ability to catalyze the NAD(P)H-dependent reduction of 2,6-dichlorophenolindophenol and nitroblue tetrazolium. Nitrite release from either PNP or 4-nitrocatechol was inhibited by the flavoprotein inhibitor methimazole. Our results indicate that the two monooxygenations of PNP to THB are catalyzed by a single two-component enzyme system comprising a flavoprotein reductase and an oxygenase.

  摘要 代谢 p -硝基苯酚（PNP）的细菌会通过对苯二酚或 1,2,4-三羟基苯（THB）将底物氧化为 3-酮基二酸；然而，通过 THB 对 PNP 进行生物降解的途径的初始步骤尚不清楚。PNP 最初羟基化的产物可能是 4-硝基邻苯二酚或 4-硝基间苯二酚。在这里，我们描述了由 芽孢杆菌 JS905 通过选择性富集从印度的农业土壤中分离出来。生长了 PNP 的 JS905 的洗涤细胞从 PNP 和 4-硝基邻苯二酚中释放出的亚硝酸盐达到了一定的数量。用从生长 PNP 的细胞中提取的提取物进行的实验表明，最初的反应是 PNP 发生羟基化反应，生成 4-硝基邻苯二酚。随后，4-硝基邻苯二酚被氧化成 THB，同时以亚硝酸盐的形式脱去硝基。通过阴离子交换色谱法和尺寸排阻色谱法，部分纯化了催化 PNP 两种连续单氧化作用的酶，并将其分离为两种成分。这两种成分都是依赖于 NADH 从 PNP 或 4-硝基儿茶酚中氧化释放亚硝酸盐所必需的。根据催化 2,6-二氯苯酚吲哚和硝基蓝四氮唑的 NAD(P)H 依赖性还原能力，确定其中一种成分为还原酶。黄素蛋白抑制剂甲巯咪唑可抑制 PNP 或 4-硝基邻苯二酚释放亚硝酸盐。我们的研究结果表明，从 PNP 到 THB 的两种单加氧作用是由黄素蛋白还原酶和加氧酶组成的单个双组分酶系统催化的。
• A Novel <i>p</i> -Nitrophenol Degradation Gene Cluster from a Gram-Positive Bacterium, <i>Rhodococcus opacus</i> SAO101
  作者：Wataru Kitagawa、Nobutada Kimura、Yoichi Kamagata

  DOI：10.1128/jb.186.15.4894-4902.2004

  日期：2004.8

  p -Nitrophenol (4-NP) is recognized as an environmental contaminant; it is used primarily for manufacturing medicines and pesticides. To date, several 4-NP-degrading bacteria have been isolated; however, the genetic information remains very limited. In this study, a novel 4-NP degradation gene cluster from a gram-positive bacterium, Rhodococcus opacus SAO101, was identified and characterized. The deduced amino acid sequences of npcB , npcA , and npcC showed identity with phenol 2-hydroxylase component B (reductase, PheA2) of Geobacillus thermoglucosidasius A7 (32%), with 2,4,6-trichlorophenol monooxygenase (TcpA) of Ralstonia eutropha JMP134 (44%), and with hydroxyquinol 1,2-dioxygenase (ORF2) of Arthrobacter sp. strain BA-5-17 (76%), respectively. The npcB , npcA , and npcC genes were cloned into pET-17b to construct the respective expression vectors pETnpcB, pETnpcA, and pETnpcC. Conversion of 4-NP was observed when a mixture of crude cell extracts of Escherichia coli containing pETnpcB and pETnpcA was used in the experiment. The mixture converted 4-NP to hydroxyquinol and also converted 4-nitrocatechol (4-NCA) to hydroxyquinol. Furthermore, the crude cell extract of E. coli containing pETnpcC converted hydroxyquinol to maleylacetate. These results suggested that npcB and npcA encode the two-component 4-NP/4-NCA monooxygenase and that npcC encodes hydroxyquinol 1,2-dioxygenase. The npcA and npcC mutant strains, SDA1 and SDC1, completely lost the ability to grow on 4-NP as the sole carbon source. These results clearly indicated that the cloned npc genes play an essential role in 4-NP mineralization in R. opacus SAO101.

  摘要 p -硝基苯酚（4-NP）被认为是一种环境污染物，主要用于制造药物和杀虫剂。迄今为止，已分离出几种降解 4-NP 的细菌，但遗传信息仍然非常有限。本研究从一种革兰氏阳性细菌中发现了一个新的 4-NP 降解基因簇、 乳清红球菌 SAO101 中的一个新型 4-NP 降解基因簇。推导出了 npcB , npcA 和 npcC 与热葡糖苷酸革囊菌的苯酚 2-羟化酶 B 组份（还原酶，PheA2）显示出相同性 与 2,4,6-三羟基苯酚还原酶 B 组份（还原酶，PheA2）的同一性。 的 2,4,6-三氯苯酚单加氧酶（TcpA）的同一性。 的 2,4,6-三氯苯酚单加氧酶（TcpA JMP134（44%），以及羟基喹啉 1,2-二氧 化酶（ORF2） 节杆菌 菌株 BA-5-17 的羟基对苯二酚 1,2-二氧化酶（ORF2）（76%）。在 npcB , npcA 和 npcC 基因克隆到 pET-17b 中，分别构建表达载体 pETnpcB、pETnpcA 和 pETnpcC。当大肠杆菌的粗细胞提取物与 4-NP 的混合物混合时，可观察到 4-NP 的转化。 大肠杆菌 在实验中使用含有 pETnpcB 和 pETnpcA 的大肠杆菌粗细胞提取物混合物时，观察到了 4-NP 的转化。该混合物将 4-NP 转化为羟基苯酚，还将 4-硝基邻苯二酚（4-NCA）转化为羟基苯酚。此外，大肠杆菌的粗细胞提取物 大肠杆菌 含有 pETnpcC 的大肠杆菌细胞提取物将羟基苯酚转化为马来乙酸酯。这些结果表明 npcB 和 npcA 编码双组分 4-NP/4-NCA 单加氧酶，而 npcC 编码羟基喹啉 1,2-二氧合酶。npcA npcA 和 npcC 突变株 SDA1 和 SDC1 完全丧失了以 4-NP 为唯一碳源的生长能力。这些结果清楚地表明，克隆的 npc 基因在 4-NP 矿化过程中发挥了重要作用。 R. opacus SAO101。
• Fe-superoxide dismutase and 2-hydroxy-1,4-benzoquinone reductase preclude the auto-oxidation step in 4-aminophenol metabolism by Burkholderia sp. strain AK-5
  作者：Shinji Takenaka、Jyun Koshiya、Susumu Okugawa、Akiko Takata、Shuichiro Murakami、Kenji Aoki

  DOI：10.1007/s10532-010-9369-5

  日期：2011.2

  Burkholderia sp. strain AK-5 converts 4-aminophenol to maleylacetic acid via 1,2,4-trihydroxybenzene, which is unstable in vitro and non-enzymatically auto-oxidized to 2-hydroxy-1,4-benzoquinone. Crude extract of strain AK-5 retarded the auto-oxidation and reduced the substrate analogue, 2,6-dimethoxy-1,4-benzoquinone, in the presence of NADH. The two enzymes responsible were purified to homogeneity. The deduced amino acid sequence of the enzyme that inhibited the auto-oxidation showed a high level of identity to sequences of iron-containing superoxide dismutases (Fe-SODs) and contained a conserved metal-ion-binding site; the purified enzyme showed superoxide dismutase activity and contained 1 mol of Fe per mol of enzyme, identifying it as Fe-SOD. Among three type SODs tested, Fe-SOD purified here inhibited the auto-oxidation most efficiently. The other purified enzyme showed a broad substrate specificity toward benzoquinones, including 2-hydroxy-1,4-benzoquinone, converting them to the corresponding 1,4-benzenediols; the enzyme was identified as 2-hydroxy-1,4-benzoquinone reductase. The deduced amino acid sequence did not show a high level of identity to that of benzoquinone reductases from bacteria and fungi that degrade chlorinated phenols or nitrophenols. The indirect role of Fe-SOD in 1,2,4-trihydroxybenzene metabolism is probably to scavenge and detoxify reactive species that promote the auto-oxidation of 1,2,4-trihydroxybenzene in vivo. The direct role of benzoquinone reductase would be to convert the auto-oxidation product back to 1,2,4-trihydroxybenzene. These two enzymes together with 1,2,4-trihydroxybenzene 1,2-dioxygenase convert 1,2,4-trihydroxybenzene to maleylacetic acid.