{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,2]],"date-time":"2026-05-02T01:11:54Z","timestamp":1777684314970,"version":"3.51.4"},"reference-count":71,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,1,19]],"date-time":"2021-01-19T00:00:00Z","timestamp":1611014400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>We have shown that autoxidized polyphenolic nutraceuticals oxidize H2S to polysulfides and thiosulfate and this may convey their cytoprotective effects. Polyphenol reactivity is largely attributed to the B ring, which is usually a form of hydroxyquinone (HQ). Here, we examine the effects of HQs on sulfur metabolism using H2S- and polysulfide-specific fluorophores (AzMC and SSP4, respectively) and thiosulfate sensitive silver nanoparticles (AgNP). In buffer, 1,4-dihydroxybenzene (1,4-DB), 1,4-benzoquinone (1,4-BQ), pyrogallol (PG) and gallic acid (GA) oxidized H2S to polysulfides and thiosulfate, whereas 1,2-DB, 1,3-DB, 1,2-dihydroxy,3,4-benzoquinone and shikimic acid did not. In addition, 1,4-DB, 1,4-BQ, PG and GA also increased polysulfide production in HEK293 cells. In buffer, H2S oxidation by 1,4-DB was oxygen-dependent, partially inhibited by tempol and trolox, and absorbance spectra were consistent with redox cycling between HQ autoxidation and H2S-mediated reduction. Neither 1,2-DB, 1,3-DB, 1,4-DB nor 1,4-BQ reduced polysulfides to H2S in either 21% or 0% oxygen. Epinephrine and norepinephrine also oxidized H2S to polysulfides and thiosulfate; dopamine and tyrosine were ineffective. Polyphenones were also examined, but only 2,5-dihydroxy- and 2,3,4-trihydroxybenzophenones oxidized H2S. These results show that H2S is readily oxidized by specific hydroxyquinones and quinones, most likely through the formation of a semiquinone radical intermediate derived from either reaction of oxygen with the reduced quinones, or from direct reaction between H2S and quinones. We propose that polysulfide production by these reactions contributes to the health-promoting benefits of polyphenolic nutraceuticals.<\/jats:p>","DOI":"10.3390\/ijms22020961","type":"journal-article","created":{"date-parts":[[2021,1,19]],"date-time":"2021-01-19T11:39:55Z","timestamp":1611056395000},"page":"961","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Oxidation of Hydrogen Sulfide by Quinones: How Polyphenols Initiate Their Cytoprotective Effects"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0178-2203","authenticated-orcid":false,"given":"Kenneth R.","family":"Olson","sequence":"first","affiliation":[{"name":"Indiana University School of Medicine\u2014South Bend Center, South Bend, IN 46617, USA"},{"name":"Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yan","family":"Gao","sequence":"additional","affiliation":[{"name":"Indiana University School of Medicine\u2014South Bend Center, South Bend, IN 46617, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Karl D.","family":"Straub","sequence":"additional","affiliation":[{"name":"Central Arkansas Veteran\u2019s Healthcare System, Little Rock, AR 72205, USA"},{"name":"Departments of Medicine and Biochemistry, University of Arkansas for Medical Sciences, Little Rock, AR 72202, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1021\/acs.jafc.8b06146","article-title":"Recent Advances in the Understanding of the Health Benefits and Molecular Mechanisms Associated with Green Tea Polyphenols","volume":"67","author":"Xing","year":"2019","journal-title":"J. Agric. Food Chem."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"65","DOI":"10.1016\/j.abb.2010.06.013","article-title":"The antioxidant and pro-oxidant activities of green tea polyphenols: A role in cancer prevention","volume":"501","author":"Lambert","year":"2010","journal-title":"Arch. Biochem. Biophys."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Miyata, Y., Matsuo, T., Araki, K., Nakamura, Y., Sagara, Y., Ohba, K., and Sakai, H. (2018). Anticancer Effects of Green Tea and the Underlying Molecular Mechanisms in Bladder Cancer. Medicines, 5.","DOI":"10.3390\/medicines5030087"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Mao, X., Xiao, X., Chen, D., Yu, B., and He, J. (2019). Tea and Its Components Prevent Cancer: A Review of the Redox-Related Mechanism. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20215249"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Shirakami, Y., and Shimizu, M. (2018). Possible Mechanisms of Green Tea and Its Constituents against Cancer. Molecules, 23.","DOI":"10.3390\/molecules23092284"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"757","DOI":"10.1161\/ATVBAHA.117.309048","article-title":"Catechins as Potential Mediators of Cardiovascular Health","volume":"37","author":"Mangels","year":"2017","journal-title":"Arter. Thromb. Vasc. Biol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.ctim.2019.08.019","article-title":"The effect of green tea on C-reactive protein and biomarkers of oxidative stress in patients with type 2 diabetes mellitus: A systematic review and meta-analysis","volume":"46","author":"Asbaghi","year":"2019","journal-title":"Complement. Ther. Med."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Suzuki, T., Pervin, M., Goto, S., Isemura, M., and Nakamura, Y. (2016). Beneficial Effects of Tea and the Green Tea Catechin Epigallocatechin-3-gallate on Obesity. Molecules, 21.","DOI":"10.3390\/molecules21101305"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Pervin, M., Unno, K., Ohishi, T., Tanabe, H., Miyoshi, N., and Nakamura, Y. (2018). Beneficial Effects of Green Tea Catechins on Neurodegenerative Diseases. Molecules, 23.","DOI":"10.3390\/molecules23061297"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Pervin, M., Unno, K., Takagaki, A., Isemura, M., and Nakamura, Y. (2019). Function of Green Tea Catechins in the Brain: Epigallocatechin Gallate and its Metabolites. Int. J. Mol. Sci., 20.","DOI":"10.3390\/ijms20153630"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.redox.2013.12.022","article-title":"New insights into the mechanisms of polyphenols beyond antioxidant properties; lessons from the green tea polyphenol, epigallocatechin 3-gallate","volume":"2","author":"Kim","year":"2014","journal-title":"Redox Biol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1128\/AEM.01963-06","article-title":"Green tea polyphenols function as prooxidants to activate oxidative-stress-responsive transcription factors in yeasts","volume":"73","author":"Maeta","year":"2007","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1384","DOI":"10.1016\/j.freeradbiomed.2008.07.023","article-title":"Covalent modification of proteins by green tea polyphenol (-)-epigallocatechin-3-gallate through autoxidation","volume":"45","author":"Ishii","year":"2008","journal-title":"Free Radic. Biol. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1762","DOI":"10.1021\/tx050151l","article-title":"Synthesis and structure identification of thiol conjugates of (-)-epigallocatechin gallate and their urinary levels in mice","volume":"18","author":"Sang","year":"2005","journal-title":"Chem. Res. Toxicol."},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Saeki, K., Hayakawa, S., Nakano, S., Ito, S., Oishi, Y., Suzuki, Y., and Isemura, M. (2018). In Vitro and In Silico Studies of the Molecular Interactions of Epigallocatechin-3-O-gallate (EGCG) with Proteins That Explain the Health Benefits of Green Tea. Molecules, 23.","DOI":"10.3390\/molecules23061295"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"101731","DOI":"10.1016\/j.redox.2020.101731","article-title":"Green tea polyphenolic antioxidants oxidize hydrogen sulfide to thiosulfate and polysulfides: A possible new mechanism underpinning their biological action","volume":"37","author":"Olson","year":"2020","journal-title":"Redox Biol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2140","DOI":"10.1002\/1873-3468.13090","article-title":"Biological hydropersulfides and related polysulfides\u2014A new concept and perspective in redox biology","volume":"592","author":"Fukuto","year":"2018","journal-title":"FEBS Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1089\/ars.2012.4944","article-title":"The gasotransmitter hydrogen sulfide induces nrf2-target genes by inactivating the keap1 ubiquitin ligase substrate adaptor through formation of a disulfide bond between cys-226 and cys-613","volume":"19","author":"Hourihan","year":"2013","journal-title":"Antioxid. Redox Signal."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1906","DOI":"10.1089\/ars.2012.4645","article-title":"Hydrogen sulfide protects against cellular senescence via S-sulfhydration of Keap1 and activation of Nrf2","volume":"18","author":"Yang","year":"2013","journal-title":"Antioxid. Redox Signal."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.freeradbiomed.2013.05.045","article-title":"How do nutritional antioxidants really work: Nucleophilic tone and para-hormesis versus free radical scavenging in vivo","volume":"66","author":"Forman","year":"2014","journal-title":"Free Radic. Biol. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1016\/S0304-4165(01)00230-6","article-title":"Kinetic analysis and mechanistic aspects of autoxidation of catechins","volume":"1569","author":"Mochizuki","year":"2002","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2632","DOI":"10.1271\/bbb.67.2632","article-title":"Production of hydrogen peroxide by polyphenols and polyphenol-rich beverages under quasi-physiological conditions","volume":"67","author":"Akagawa","year":"2003","journal-title":"Biosci. Biotechnol. Biochem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"429","DOI":"10.1038\/nrc2641","article-title":"Cancer prevention by tea: Animal studies, molecular mechanisms and human relevance","volume":"9","author":"Yang","year":"2009","journal-title":"Nat. Rev. Cancer"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"R340","DOI":"10.1152\/ajpregu.00202.2017","article-title":"Fluorescence quenching by metal centered porphyrins and poryphyrin enzymes","volume":"313","author":"Olson","year":"2017","journal-title":"Am. J. Physiol. Regul. Integr. Comp. Physiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3176","DOI":"10.1021\/jo4001178","article-title":"Degradation of 2,5-dihydroxy-1,4-benzoquinone by hydrogen peroxide: A combined kinetic and theoretical study","volume":"78","author":"Hosoya","year":"2013","journal-title":"J. Org. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"566","DOI":"10.1021\/i300008a010","article-title":"Catalytic oxidation of hydroquinone to quinone using molecular oxygen","volume":"21","author":"Radel","year":"1982","journal-title":"Ind. Eng. Chem. Prod. Res. Dev."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"112","DOI":"10.31788\/RJC.2020.1315612","article-title":"Kinetics and Mechanism of the Aqueous Phase Oxidation of Hydrogen Sulfide by Oxygen: Catalyzed by Hydroquinone","volume":"13","author":"Rathore","year":"2020","journal-title":"Rasayan J. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1830","DOI":"10.1021\/jo7024543","article-title":"The Unusual Reaction of Semiquinone Radicals with Molecular Oxygen","volume":"73","author":"Valgimigli","year":"2008","journal-title":"J. Org. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1489","DOI":"10.1021\/ja01248a018","article-title":"Oxidation Processes. XV.1The Effect of Reducing Agents on the Autoxidation of Some Photographic Developing Agents","volume":"68","author":"Weissberger","year":"1943","journal-title":"J. Am. Chem. Soc."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.redox.2017.11.009","article-title":"Metabolism of hydrogen sulfide (H2S) and Production of Reactive Sulfur Species (RSS) by superoxide dismutase","volume":"15","author":"Olson","year":"2017","journal-title":"Redox Biol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/j.tox.2017.06.006","article-title":"The electrophilic character of quinones is essential for the suppression of Bach1","volume":"387","author":"Su","year":"2017","journal-title":"Toxicology"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7470","DOI":"10.1021\/jp101723s","article-title":"Absorption spectrum, mass spectrometric properties, and electronic structure of 1,2-benzoquinone","volume":"114","author":"Albarran","year":"2010","journal-title":"J. Phys. Chem. A"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"465","DOI":"10.1002\/kin.550210609","article-title":"A Kinetic Study of the Air Oxidation of Pyrogallol and Purpurogallin","volume":"21","author":"Abrash","year":"1989","journal-title":"Int. J. Chem. Kinet."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1153","DOI":"10.1038\/1811153a0","article-title":"Autoxidation of pyrogallol: General characteristics and inhibition by catalase","volume":"181","author":"Siegel","year":"1958","journal-title":"Nature"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1016\/S0021-9258(19)77264-0","article-title":"Oxidation of pyrogallol to purpurogallin by crystallin catalase","volume":"205","author":"Tauber","year":"1953","journal-title":"J. Biol. Chem."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/j.mrgentox.2003.11.002","article-title":"Metal-mediated oxidative damage to cellular and isolated DNA by gallic acid, a metabolite of antioxidant propyl gallate","volume":"558","author":"Kobayashi","year":"2004","journal-title":"Mutat. Res."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1515\/afmnai-2015-0013","article-title":"Influence of Zn(II) Ion on the Autoxidation of Pyrogallol and Gallic Acid in Weakly Acidic Aqueous Solutions\/Uticaj Zn(II) jona na autooksidaciju pirogalola i galne kiseline u slabo kiselim vodenim rastvorima","volume":"32","year":"2015","journal-title":"Acta Fac. Med. Naissensis"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/0009-2797(91)90022-Y","article-title":"Effects of superoxide dismutase on the autoxidation of 1,4-hydroquinone","volume":"80","author":"Eyer","year":"1991","journal-title":"Chem. Biol. Interact."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1359","DOI":"10.1021\/tx8000175","article-title":"Semiquinone radicals from oxygenated polychlorinated biphenyls: Electron paramagnetic resonance studies","volume":"21","author":"Song","year":"2008","journal-title":"Chem. Res. Toxicol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/S0304-4165(00)00099-4","article-title":"Spectroscopic detection of adrenaline-quinone formation in micelles","volume":"1523","author":"Polewski","year":"2000","journal-title":"Biochim. Biophys. Acta"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1125","DOI":"10.1089\/ars.2020.8132","article-title":"Are Reactive Sulfur Species the New Reactive Oxygen Species?","volume":"33","author":"Olson","year":"2020","journal-title":"Antioxid. Redox Signal."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"85","DOI":"10.1016\/j.niox.2014.06.003","article-title":"Working with \u201cH2S\u201d: Facts and apparent artifacts","volume":"41","author":"Wedmann","year":"2014","journal-title":"Nitric Oxide"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1016\/j.ejphar.2014.01.009","article-title":"Hydrogen sulfide protected gastric epithelial cell from ischemia\/reperfusion injury by Keap1 s-sulfhydration, MAPK dependent anti-apoptosis and NF-kappaB dependent anti-inflammation pathway","volume":"725","author":"Guo","year":"2014","journal-title":"Eur. J. Pharmacol."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"3548","DOI":"10.1016\/j.febslet.2013.09.013","article-title":"Polysulfide exerts a protective effect against cytotoxicity caused by t-buthylhydroperoxide through Nrf2 signaling in neuroblastoma cells","volume":"587","author":"Koike","year":"2013","journal-title":"FEBS Lett."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"9433","DOI":"10.1038\/s41598-017-09648-6","article-title":"Neglected role of hydrogen sulfide in sulfur mustard poisoning: Keap1 S-sulfhydration and subsequent Nrf2 pathway activation","volume":"7","author":"Meng","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1093\/toxsci\/kfu272","article-title":"Antioxidant effects of hydrogen sulfide on left ventricular remodeling in smoking rats are mediated via PI3K\/Akt-dependent activation of Nrf2","volume":"144","author":"Zhou","year":"2015","journal-title":"Toxicol. Sci."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"4529","DOI":"10.1021\/jf040382i","article-title":"Oxidation of tea extracts and tea catechins by molecular oxygen","volume":"53","author":"Roginsky","year":"2005","journal-title":"J. Agric. Food Chem."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"1858","DOI":"10.1021\/ja01673a014","article-title":"Reduction Potentials of Quinones. II. The Potentials of Certain Derivatives of Benzoquinone, Naphthoquinone and Anthraquinone","volume":"46","author":"Conant","year":"1924","journal-title":"J. Am. Chem. Soc."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1021\/ja01269a007","article-title":"The Influence of Catechol on the Stability of o-Benzoquinone in Aqueous Solutions","volume":"60","author":"Dawson","year":"1938","journal-title":"J. Am. Chem. Soc."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/S0021-9258(18)35614-X","article-title":"The chemistry of melanin; mechanism of the oxidation of dihydroxyphenylalanine by tyrosinase","volume":"172","author":"Mason","year":"1948","journal-title":"J. Biol. Chem."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"1003","DOI":"10.1021\/ja01633a017","article-title":"Dipole Moments and Absorption Spectra of o-Benzoquinone and its Related Substances","volume":"76","author":"Nagakura","year":"1954","journal-title":"J. Am. Chem. Soc."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2951","DOI":"10.1021\/jo062677w","article-title":"Regioselective (biomimetic) synthesis of a pentasulfane from ortho-benzoquinone","volume":"72","author":"Aebisher","year":"2007","journal-title":"J. Org. Chem."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1555","DOI":"10.1021\/ja00370a018","article-title":"o-Benzosemiquinone and its metal chelates. Electron spin resonance investigation of radicals from the photolysis of catechol in the presence of complexing metal ions","volume":"104","author":"Felix","year":"1982","journal-title":"J. Am. Chem. Soc."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"3170","DOI":"10.1016\/S0021-9258(19)45228-9","article-title":"The role of superoxide anion in the autoxidation of epinephrine and a simple assay for superoxide dismutase","volume":"247","author":"Misra","year":"1972","journal-title":"J. Biol. Chem."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1002\/anie.198103891","article-title":"\u201cSpin-Stabilization\u201d via Complex Formation; ESR Investigation of some Catecholamine-Semiquinones","volume":"20","author":"Stegmann","year":"1981","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"7584","DOI":"10.1016\/S0021-9258(17)42830-4","article-title":"Peroxidatic oxidation of catecholamines. A kinetic electron spin resonance investigation using the spin stabilization approach","volume":"259","author":"Kalyanaraman","year":"1984","journal-title":"J. Biol. Chem."},{"key":"ref_57","first-page":"389","article-title":"The Oxidation of Catecholamines and 6-Hydroxydopamine by Molecular Oxygen: Effect of Ascorbate","volume":"52","author":"Roginsky","year":"1997","journal-title":"Z. Nat."},{"key":"ref_58","doi-asserted-by":"crossref","unstructured":"Olson, K.R., Gao, Y., Arif, F., Patel, S., Yuan, X., Mannam, V., Howard, S., Batinic-Haberle, I., Fukuto, J., and Minnion, M. (2019). Manganese Porphyrin-Based SOD Mimetics Produce Polysulfides from Hydrogen Sulfide. Antioxidants, 8.","DOI":"10.3390\/antiox8120639"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1021\/acs.chemrestox.6b00256","article-title":"Formation and Biological Targets of Quinones: Cytotoxic versus Cytoprotective Effects","volume":"30","author":"Bolton","year":"2017","journal-title":"Chem. Res. Toxicol."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"425","DOI":"10.2174\/1389200023337388","article-title":"The metabolism and toxicity of quinones, quinonimines, quinone methides, and quinone-thioethers","volume":"3","author":"Monks","year":"2002","journal-title":"Curr. Drug Metab."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"1527","DOI":"10.1021\/tx200140s","article-title":"Structural determinant of chemical reactivity and potential health effects of quinones from natural products","volume":"24","author":"Tu","year":"2011","journal-title":"Chem. Res. Toxicol."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"1266","DOI":"10.1016\/j.freeradbiomed.2006.07.009","article-title":"One-electron oxidation of catecholamines generates free radicals with an in vitro toxicity correlating with their lifetime","volume":"41","author":"Terland","year":"2006","journal-title":"Free Radic. Biol. Med."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/0891-5849(89)90116-0","article-title":"Is the autoxidation of catecholamines involved in ischemia-reperfusion injury?","volume":"6","author":"Jewett","year":"1989","journal-title":"Free Radic. Biol. Med."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1111\/j.1749-6632.1963.tb42896.x","article-title":"The cytotoxicity of melanin precursors","volume":"100","author":"Hochstein","year":"1963","journal-title":"Ann. N. Y. Acad. Sci."},{"key":"ref_65","first-page":"887","article-title":"Oxygen-dependent reaction of 6-hydroxydopamine, 5,6-dihydroxytryptamine, and related compounds with proteins in vitro: A model for cytotoxicity","volume":"12","author":"Rotman","year":"1976","journal-title":"Mol. Pharmacol."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1016\/0891-5849(96)00033-0","article-title":"Oxidative damage caused by free radicals produced during catecholamine autoxidation: Protective effects of O-methylation and melatonin","volume":"21","author":"Miller","year":"1996","journal-title":"Free Radic. Biol. Med."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/j.redox.2018.07.016","article-title":"A selective and sensitive method for quantification of endogenous polysulfide production in biological samples","volume":"18","author":"Bibli","year":"2018","journal-title":"Redox Biol."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.freeradbiomed.2019.02.011","article-title":"Effects of inhibiting antioxidant pathways on cellular hydrogen sulfide and polysulfide metabolism","volume":"135","author":"Olson","year":"2019","journal-title":"Free Radic. Biol. Med."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.freeradbiomed.2019.10.410","article-title":"Are the beneficial effects of \u2018antioxidant\u2019 lipoic acid mediated through metabolism of reactive sulfur species?","volume":"146","author":"Olson","year":"2019","journal-title":"Free Radic. Biol. Med."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"1152","DOI":"10.1021\/acssensors.7b00257","article-title":"High-Performance Colorimetric Detection of Thiosulfate by Using Silver Nanoparticles for Smartphone-Based Analysis","volume":"2","author":"Dong","year":"2017","journal-title":"ACS Sens."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"1980","DOI":"10.1039\/C8CC00187A","article-title":"Goodbye to S(2-) in aqueous solution","volume":"54","author":"May","year":"2018","journal-title":"Chem. Commun. (Camb.)"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/2\/961\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:12:57Z","timestamp":1760159577000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/22\/2\/961"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,19]]},"references-count":71,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,1]]}},"alternative-id":["ijms22020961"],"URL":"https:\/\/doi.org\/10.3390\/ijms22020961","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,19]]}}}