2,6-Dichloro-1,4-benzoquinone

Chemical compound July 2026 2,6-Dichloro-1,4-benzoquinone.svg 125px 2,6-Dichloro-p-benzoquinone 2,6-Dichlorobenzoquinone 697-91-6 147298 12246 211-810-0 C21103 12771 1S/C6H2Cl2O2/c7-4-1-3(9)2-5(8)6(4)10/h1-2H JCARTGJGWCGSSU-UHFFFAOYSA-N C1=C(C(=O)C(=CC1=O)Cl)Cl 6 2 2 2 123 07 Warning 315 319 335 261 264 264+265 270 271 280 301+317 302+352 304+340 305+351+338 319 321 330 332+317 337+317 362+364 403+233 405 501 2,6-Dichloro-1,4-benzoquinone, also known as 2,6-DCBQ, an organic compound that emerges as a disinfection by-product (DBP) that is frequently found in drinking water disinfected with chlorine or chloramines.Qin Feng Zhao Yuan-Yuan Zhao Yuli Boyd Jessica M. Zhou Wenjun Li Xing-Fang 2010-01-18 A Toxic Disinfection By-product, 2,6-Dichloro-1,4-benzoquinone, Identified in Drinking Water https://onlinelibrary.wiley.com/doi/10.1002/anie.200904934 Angewandte Chemie International Edition en 49 4 790–792 10.1002/anie.200904934 20025006 1433-7851 subscription 2,6-DCBQ is a member of the halobenzoquinones (HBQ), which in recent years has gained significant attention in environmental toxicology due to high levels encountered in drinking water. 2,6-DCBQ has been linked to neurodevelopmental toxicity due to reactive oxygen species formation inhibiting the PI3K/AKT/mTOR pathway.Zhang Liang Lv Haixiang Li Xuchao Wan Hu He Shun Li Jianhong Ma Kangsheng September 2023 Sublethal effects of acetamiprid and afidopyropen on Harmonia axyridis: insights from transcriptomics analysis Ecotoxicology and Environmental Safety en 262 115203 10.1016/j.ecoenv.2023.115203 37406606 free 2023EcoES.26215203Z DCBQ does not only have high toxic potency but is also a potential carcinogen.Zuo Yu-Ting Hu Yu Lu Wei-Wei Cao Jing-Jing Wang Fan Han Xue Lu Wen-Qing Liu Ai-Lin January 2017 Toxicity of 2,6-dichloro-1,4-benzoquinone and five regulated drinking water disinfection by-products for the Caenorhabditis elegans nematode Journal of Hazardous Materials 321 456–463 10.1016/j.jhazmat.2016.09.038 27669387 2017JHzM..321..456Z 0304-3894 2,6-DCBQ is frequently used in biochemistry to study the QB-binding site in Photosystem II (PSII). It is used as an artificial electron acceptor (AEAs) with a molecular structure similar to plastoquinone's.Kamada Shinji Nakajima Yoshiki Shen Jian-Ren July 2023 Structural insights into the action mechanisms of artificial electron acceptors in photosystem II Journal of Biological Chemistry 299 7 104839 10.1016/j.jbc.2023.104839 free 0021-9258 10300377 37209822 History A high yield and efficient synthesis of 2,6-DCBQ was first provided in 1886 by the chemist Kollrep A. during a systematic investigation into derivatives of phenols. Kollrepp utilized p-nitrophenol as a starting material, converting it into mono- and dichlornated benzoquinones making vibrant yellow cristalline structure.Hunter W. H. Kvalnes D. E. July 1933 Eine optische Methode zum Studium reversibler organischer Oxydations-Reduktionssysteme Zeitschrift für Analytische Chemie 93 7–8 282–284 10.1007/bf01404772 1618-2642 Researchers in 1932 found an optical method for studying reversible organic oxidation-reduction systems, by using hydroquinones to determine equilibrium constants.Kollrepp Alexander January 1886 Ueber Derivate der gechlorten Para-Nitrophenole Justus Liebigs Annalen der Chemie 234 1 1–34 10.1002/jlac.18862340102 0075-4617 In 1956 Wessels and van der Veen explored how chlorinated quinones could shuttle electrons. By researching the action of benzoquinones on the Hill reaction. It became a standard toolTerentyev Vasily V. Shukshina Anna K. Chetverkina Angelina A. 2023-03-15 Action of 2,6-Dichloro-1,4-benzoquinone on the O2-Evolving Activity of Photosystem II in Chlamydomonas reinhardtii Cells with and without Cell Wall: Inhibitory Effect of Its Oxidized Form Cells en 12 6 907 10.3390/cells12060907 free 2073-4409 10046965 36980248 for isolating the activity of Photosystem II, because of its specific redox potential.Wessels J.S.C. van der Veen R. The action of some derivatives of phenylurethan and of 3-phenyl-1,1-dimethylurea on the Hill reaction Biochimica et Biophysica Acta January 1956 19 3 548–549 10.1016/0006-3002(56)90481-4 13315318 Qin et al. detected and quantified 2,6-DCBQ from Canadian municipal drinking water samples. By using highly sensitive liquid chromatography mass spectrometry, 2,6-DCBQ was identified as a major DBP formed during chlorination of raw water containing phenolic contaminants. Since this discovery, research about 2,6-DCBQ has shifted towards its role in human health.Wang Yuanyuan Wang Fengbang Li Lulu Zhang Lan Song Maoyong Jiang Guibin 2024-05-28 Comprehensive Toxicological Assessment of Halobenzoquinones in Drinking Water at Environmentally Relevant Concentration https://pubs.acs.org/doi/10.1021/acs.est.4c03308 Environmental Science & Technology en 58 21 9125–9134 10.1021/acs.est.4c03308 38743861 2024EnST...58.9125W 0013-936X subscription Structure and reactivity Of the halobenzoquinones, DCBQ is the most commonly detected in drinking waters, up to 275 ng/L, and in chlorinated swimming pools, up to 299 ng/L. DCBQ can undergo hydrolysis, and its main hydrolysis product is DCBQ-OH.Hung Stephanie Mohan Aarthi Reckhow David A. Godri Pollitt Krystal J. November 2019 Assessment of the in vitro toxicity of the disinfection byproduct 2,6-dichloro-1,4-benzoquinone and its transformed derivatives Chemosphere 234 902–908 10.1016/j.chemosphere.2019.06.086 31519098 2019Chmsp.234..902H 0045-6535 The transformation of DCBQ is much quicker in cell tissues than in water. The half-life of DCBQ is ~7h in water compared to ~1h in cell cultures, and is thus more reactive in cell tissues. In the human body, DCBQs can produce reactive oxidative species (ROS) at certain doses, causing mitochondrial dysfunction by reducing the mitochondrial membrane potential, and could promote the mitochondrial apoptosis pathway. DCBQ causes oxidative stress.Liu Ting Chen Xin Li Wanling Zhang Xu Wang Gaihua Wang Jun Liang Lanqian Yang Fan Li Juan Li Jinhua September 2023 Oxidative stress as a key event in 2,6-dichloro-1,4-benzoquinone-induced neurodevelopmental toxicity Ecotoxicology and Environmental Safety 263 115357 10.1016/j.ecoenv.2023.115357 0147-6513 free 37598546 2023EcoES.26315357L DCBQ induced a concentration-dependent decrease in cell viability. It has also been found that DCBQ might cause nuclear DNA damage.KROLL Jürgen RAWEL Harshadrai M. ROHN Sascha 2003 Reactions of Plant Phenolics with Food Proteins and Enzymes under Special Consideration of Covalent Bonds Food Science and Technology Research 9 3 205–218 10.3136/fstr.9.205 1344-6606 Structure activity relationship The structure of Benzoquinones may explain their toxicity. Benzoquinones are electrophilic and can undergo reactions with nucleophilic groups, for instance on amino acids, altering structure and function of the proteins. Due to the Cl groups on the quinone ring in DCBQ, the overall electrophilicity of the HBQ is increased, which causes higher reactivity with nucleophilic groups,Du Penghui Zhao He Cao Hongbin Huang Ching-Hua Liu Wen Li Yao October 2017 Transformation of halobenzoquinones with the presence of amino acids in water: Products, pathways and toxicity Water Research 122 299–307 10.1016/j.watres.2017.06.007 28614742 2017WatRe.122..299D 0043-1354 such as glutathione, proteins, and nucleic acids. If DCBQ reacts with glutathione they form conjugates, lowering GSH levels in the cell, which might lead to GSH depletion.Wang Wei Qian Yichao Li Jinhua Aljuhani Naif Siraki Arno G. Le X. Chris Li Xing-Fang 2018-02-08 Characterization of Mechanisms of Glutathione Conjugation with Halobenzoquinones in Solution and HepG2 Cells Environmental Science & Technology 52 5 2898–2908 10.1021/acs.est.7b05945 29420883 2018EnST...52.2898W 0013-936X ADME This describes the ADME of 2,6-DCBQ. Absorption 2,6-DCBQ is mainly absorbed via the oral route, typically through the ingestion of contaminated drinking water. Dermal absorption is also considered a viable pathway following aqueous exposure. The compound's low molecular weight and moderate lipophilicity favor absorption across the gastrointestinal tract. However, the high reactivity may limit total systemic bioavailability. The quinone structure reacts rapidly with biological nucleophiles in physiological fluids, leading to localized interactions before the unchanged compound can reach systemic circulation.Zheng Lili Chen Guolong Fu Kuangtao Wang Zhen Yuan Xinyue Sun Hongjie Deng Wenjing Xu Zeqiong Lin Hongjun Hong Huachang 2025-10-07 Biotransformation and toxicity attenuation of 2,6-Dichlorobenzoquinone in simulated human gastrointestinal conditions: Insights from a systematic in vitro study https://linkinghub.elsevier.com/retrieve/pii/S0304389425025828 Journal of Hazardous Materials en 497 139663 10.1016/j.jhazmat.2025.139663 40885060 2025JHzM..49739663Z subscription Distribution Following absorption, 2,6-DCBQ distributes predominantly to highly perfused organs, such as the liver and the kidneys. Its moderate lipophilicity facilitates the crossing of cellular membranes. The quinone structure allows for redox cycling between quinone and hydroquinone within tissues. This process can lead to the formation of reactive oxygen species (ROS), contributing to intracellular oxidative stress. Due to its high reactivity and its metabolic transformation, 2,6-DCBQ does not significantly accumulate in adipose tissue.Liu Meixian Ning Zhiyuan Cheng Yong Zheng Zhiyuan Yang Xiaoxue Zheng Ting Li Na Wu Jian-Lin 2024-11-06 The key to 2,6-dichloro-1,4-benzoquinone reproductive toxicity and green tea detoxification: Covalent binding and competitive binding Ecotoxicology and Environmental Safety en 286 117239 10.1016/j.ecoenv.2024.117239 free 39454356 2024EcoES.28617239L Metabolism The metabolism of the compound primarily occurs in the liver through both reduction and conjugation pathways. A major metabolic step involves the reduction of the quinone to its corresponding hydroquinone. The main metabolic route is the detoxification via conjugation with glutathione (GSH). This phase II metabolism reaction serves to neutralize the compound's electrophilicity, facilitating safer elimination. Nevertheless, excessive or chronic exposure may lead to the depletion of cellular GSH pools, which enhances oxidative stress and potential cellular damage. The subsequent processing of these glutathione conjugates results in the formation of cysteine conjugates and mercapturic acids.Li Jinhua Wang Wei Zhang Hongquan Le X. Chris Li Xing-Fang 2014-10-01 Glutathione-Mediated Detoxification of Halobenzoquinone Drinking Water Disinfection Byproducts in T24 Cells http://academic.oup.com/toxsci/article/141/2/335/1692333/GlutathioneMediated-Detoxification-of Toxicological Sciences en 141 2 335–343 10.1093/toxsci/kfu088 1096-0929 4833019 24812012Haloquinone Standards for Research https://www.benchchem.com/product/b1663269?utm_src=pdf-interest 2026-03-09 www.benchchem.com en Excretion The elimination of 2,6-DCBQ and its derivatives occurs predominantly through the renal system. Due to its high reactivity, levels of the unchanged parent compound are negligible. Instead, the compound is excreted in the form of water-soluble metabolites, specifically mercapturic acid derivatives. Biliary excretion is a secondary possibility, but urinary elimination remains the dominant pathway for the clearance of 2,6-DCBQ metabolites from the body.Liu Ting Wang Jun Dang Xinyue Wan Siyu Luo Xi Tang Wen Du Haiying Jin Minghua Li Juan Li Jinhua 2023-03-03 Investigation of the nephrotoxicity of 2,6-dichloro-1,4-benzoquinone disinfection by-product in mice through a 28-day toxicity test https://linkinghub.elsevier.com/retrieve/pii/S0300483X23000458 Toxicology en 487 153459 10.1016/j.tox.2023.153459 36787874 2023Toxgy.48753459L subscription Mechanism of action 2,6‑Dichloro‑1,4-benzoquinone (DCBQ) exerts cytotoxic effects primarily through depletion of cellular glutathione (GSH).Zheng Lili Chen Guolong Fu Kuangtao Wang Zhen Yuan Xinyue Sun Hongjie Deng Wenjing Xu Zeqiong Lin Hongjun Hong Huachang October 2025 Biotransformation and toxicity attenuation of 2,6-Dichlorobenzoquinone in simulated human gastrointestinal conditions: Insights from a systematic in vitro study Journal of Hazardous Materials 497 139663 10.1016/j.jhazmat.2025.139663 40885060 2025JHzM..49739663Z 0304-3894 GSH is a major intracellular antioxidant that protects cells by neutralizing reactive oxygen and nitrogen species (ROS and RNS). Because of this role, cellular GSH levels are commonly used as an indicator of oxidative stress. A decrease in GSH disrupts the cellular redox balance and can act as an important signal that triggers the activation of cell death pathways.Franco Rodrigo Cidlowski John A. 2012-12-15 Glutathione Efflux and Cell Death Antioxidants & Redox Signaling 17 12 1694–1713 10.1089/ars.2012.4553 22656858 3474185 1523-0864 The reducing capacity of GSH is therefore essential for maintaining cellular survival. DCBQ belongs to a group of halobenzoquinones (HBQs), four of which have been shown to be cytotoxic to T24 human bladder carcinoma cells.Li Jinhua Wang Wei Zhang Hongquan Le X. Chris Li Xing-Fang 2014-10-01 Glutathione-Mediated Detoxification of Halobenzoquinone Drinking Water Disinfection Byproducts in T24 Cells Toxicological Sciences 141 2 335–343 10.1093/toxsci/kfu088 24812012 1096-0929 4833019 These compounds induce oxidative stress through the generation of reactive oxygen species, which can cause oxidative damage to cellular components such as DNA and proteins. In the presence of DCBQ, intracellular GSH levels are inversely correlated with ROS production and glutathione S‑transferase (GST) activity. By depleting cellular GSH, HBQs promote increased ROS formation and stimulate GST activity as part of the cellular response to oxidative stress. Binding DCBQ is an electrophilic compound, so it can bind in the human body to multiple nucleophilic compounds. DCBQ can, for instance, react with GSH, substituting the Cl groups for the GS group. DCBQ is thus being dechlorinated and can undergo Michael addition with GSH, resulting in more glutathionylated products. The second Cl group can also be removed from the compound when reacting with another GSH molecule. DCBQ can also undergo redox reactions when reacting with an electron, forming radicals. These radicals can also react with GSH, forming more conjugation products. DCBQ can also react with amino acids. When DCBQ was brought in contact with amino acids, the DCBQ was quickly removed, suggesting that the DCBQ reacted with the amino acids.Zhong Chen Zhao He Cao Hongbin Huang Ching-Hua 2021 Fast Coupling and Detoxification of Aqueous Halobenzoquinones by Extracellular Nucleophiles: The Relationship Among Structures, Pathways and Toxicity SSRN Electronic Journal 10.2139/ssrn.3981649 1556-5068 DCBQ binds to the DNA via H-bonds, a non-covalent interaction.Xiong Yue Kaw Han Yeong Zhu Lizhong Wang Wei 2021-11-11 Genotoxicity of quinone: An insight on DNA adducts and its LC-MS-based detection Critical Reviews in Environmental Science and Technology 52 23 4217–4240 10.1080/10643389.2021.2001276 1064-3389 Because of its hydrophobicity, DCBQ might be intercalated between nucleotides in a double-stranded DNA molecule [source]. This intercalation might lead to increased access to the nucleotides, possibly leading to even more oxidative damage in the DNA. Amino acids can also covalently bind to DCBQ. The amino acids undergo nucleophilic substitution with both DCBQ and DCBQ-OH, the product of DCBQ hydrolysis. Proteins can be bound by DCBQ covalently via cysteine or lysine residues. Catechins, which are naturally present in for instance green tea, can competitively bind to DCBQ, reducing the amount of proteins bound to DCBQ [16]. The proteins are covalently modified when bound to DCBQ, which might change the stability and alter the function of the protein. Reversing the mechanism The antioxidant N-acetyl-L-cysteine (NAC) is known to significantly reduce the cytotoxicity induced by DCBQ. NAC is a precursor of sulfhydryl-containing tripeptide glutathione (GSH), which is produced and kept at high levels in all cells, helping them defend against oxidative stress.Raghu Ganesh Berk Michael Campochiaro Peter A. Jaeschke Hartmut Marenzi Giancarlo Richeldi Luca Wen Fu-Qiang Nicoletti Ferdinando Calverley Peter M. A. August 2021 The Multifaceted Therapeutic Role of N-Acetylcysteine (NAC) in Disorders Characterized by Oxidative Stress Current Neuropharmacology 19 8 1202–1224 10.2174/1570159x19666201230144109 33380301 1570-159X 8719286 Once NAC is inside the cell, it is rapidly hydrolyzed to cysteine so that it can be used to form GSH. Restoring the high GSH levels in the cell. NAC is available in oral, inhalation, and intravenous (IV) formulations. Efficacy and side effects Efficacy 2,6-Dichloro-1,4-benzoquinone is primarily used in research due to its ability to participate in electron transfer reactions. In photosynthesis, it can act as an artificial electron acceptor in photosystem II. Researchers can measure and analyse electron transport activity in chloroplasts and other photosynthetic systems. The ability to accept electrons in place of natural quinones makes the compound useful for investigating the mechanisms of photosynthetic energy conversion and for evaluating the effects of inhibitors or environmental stress on photosynthetic organisms.Fufezan Christian Gross Christine M. Sjödin Martin Rutherford A. William Krieger-Liszkay Anja Kirilovsky Diana 2007-04-11 Influence of the Redox Potential of the Primary Quinone Electron Acceptor on Photoinhibition in Photosystem II Journal of Biological Chemistry en 282 17 12492–12502 10.1074/jbc.M610951200 free 17327225 2007JBiCh.28212492F In addition, 2,6-DCBQ can inhibit enzymes such as acetylcholinesterase in laboratory experiments and may exhibit antimicrobial or algal toxicity due to its reactive quinone structure.Zhang Tianqi Wang Zhaoyang Wu Liang Liu Chaonan Meng Liang Tian Fuxiang Hou Meifang Lin Haizhuan Ye Jing 2025-01-17 The Effects of Disinfection Byproduct 2,6-Dichloro-1,4-benzoquinone on the Cyanobacterium Microcystis aeruginosa: From the Perspectives of Biochemistry and Non-Targeted Metabolomics Toxics en 13 1 64 10.3390/toxics13010064 free 2305-6304 11768523 39853062 2025Toxic..13...64Z These characteristics are mainly of research interest rather than therapeutic application. Side effects Despite its usefulness in experimental studies, 2,6-DCBQ is considered a highly toxic compound, especially as an environmental contaminant formed during the chlorination of drinking water. The primary reason for its toxicity is the generation of reactive oxygen species (ROS), which leads to oxidative stress in cells. This oxidative stress can damage proteins, lipids, DNA, and can also disrupt mitochondrial function, reducing cellular energy production and promoting apoptosis.Liu Ting Chen Xin Li Wanling Zhang Xu Wang Gaihua Wang Jun Liang Lanqian Yang Fan Li Juan Li Jinhua 2023-09-02 Oxidative stress as a key event in 2,6-dichloro-1,4-benzoquinone-induced neurodevelopmental toxicity Ecotoxicology and Environmental Safety en 263 115357 10.1016/j.ecoenv.2023.115357 free 37598546 2023EcoES.26315357L Exposure to 2,6-DCBQ has been linked to several adverse biological effects. These include neurotoxicity, where the neuronal cell survival and differentiation is impaired, as well as genotoxic effects such as DNA damage and activation of cell-cycle control pathways. Studies in animals have also shown potential kidney damage and inflammatory responses in tissues.Song Weiyi Wu Kun Wu Xiling Lu Yichun Li Jing Li Jinhua Cui Mengqiao 2022-07-05 The antiestrogen-like activity and reproductive toxicity of 2,6-DCBQ on female zebrafish upon sub-chronic exposure https://linkinghub.elsevier.com/retrieve/pii/S1001074221004800 Journal of Environmental Sciences en 117 10–20 10.1016/j.jes.2021.11.012 35725062 2022JEnvS.117...10S subscription Due to its harmful side effects and its presence as a disinfection by-product, 2,6-DCBQ is considered a compound of concern in environmental and toxicological research. Toxicological data The toxicological effects of 2,6‑dichloro‑1,4‑benzoquinone (2,6‑DCBQ) have been investigated in several experimental models. In mice, a 28‑day exposure study reported renal injury following 2,6‑DCBQ exposure.Liu T, Wang J, Dang X, Wan S, Luo X, Tang W, et al. Investigation of the nephrotoxicity of 2,6-dichloro-1,4-benzoquinone disinfection by-product in mice through a 28-day toxicity test. Toxicology. 2023 Mar;487:153459. Proposed mechanisms include the activation of inflammatory pathways, oxidative stress, and apoptosis. Toxicity has also been examined in embryonic zebrafish, where exposure resulted in acute and developmental toxicity.Yang X., Wang C., Zheng Q., Liu Q., Wawryk N.J.P., Li X.F. Emerging Disinfection Byproduct 2,6-dichlorobenzoquinone Induced Cardiovascular Developmental Toxicity of Embryonic Zebrafish and Larvae: Imaging and Transcriptome Analysis. ACS Omega. 2022; 7: 45642-45653. Observed effects included impaired cardiovascular development and alterations in molecular signaling pathways. Studies using human cell lines have also reported cytotoxic effects. In kidney cells, exposure primarily induces anoikis, a form of apoptosis associated with loss of cell–matrix interactions.Xu T., Gu L., Chen Y., Wei S., Wang H., Gio X., Wang J., Yin D. Integrated transcriptomic and metabolomic analysis reveals the induction of anoikis in renal proximal tubular epithelial cells by 2,6-Dichloro-1,4-benzoquinone. Toxicology. 2025 Nov; 517: 154207. In human colon epithelial and liver cells, 2,6‑DCBQ exposure increases the production of reactive oxygen species (ROS). Prolonged low‑dose exposure in normal colon and liver cell lines has been associated with oxidative stress, DNA damage, and molecular changes that may indicate a potential role in carcinogenesis. In cell culture systems, the half‑life of 2,6‑DCBQ has been estimated to be less than one hour, and the parent compound appears to exhibit greater cytotoxicity than its transformation product.Hung S, Mohan A, Reckhow DA, Godri KJ. Assessment of the in vitro toxicity of the disinfection byproduct 2,6-dichloro-1,4-benzoquinone and its transformed derivatives. Chemosphere. 2019 Nov 1;234:902–8. References Category:Benzoquinones Category:Chloroarenes