{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T12:37:05Z","timestamp":1784205425885,"version":"3.55.0"},"reference-count":31,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T00:00:00Z","timestamp":1747872000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Medical University Lodz","award":["503\/1-079-01\/503-11-001"],"award-info":[{"award-number":["503\/1-079-01\/503-11-001"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Various polyphenols are absorbed into the bloodstream following the consumption of polyphenol-rich foods. These compounds may exhibit divergent redox properties, particularly in relation to their antioxidant or pro-oxidant activities. We evaluated the effects of six binary equimolar combinations of polyphenols with pre-established redox profiles on hydroxyl radical-dependent ultra-weak photon emission (UPE) in an Fe2+\u2013EGTA\u2013H2O2 Fenton system: gallic acid and vanillic acid, gallic acid and 3,4-dihydroxyphenylacetic acid, gallic acid and homovanillic acid, ellagic acid and 3,4-dihydroxyphenyl acetic acid, ellagic acid and homovanillic acid, and vanillic acid and homovanillic acid. The first pair of phenolics gave the expected summed redox response. The second one gave a higher redox response than expected from the sum (512 \u00b1 461% vs. 212 \u00b1 222% of enhancement of UPE, p &lt; 0.05). The remaining four pairs revealed a lower redox response than expected from the sum (p &lt; 0.05). The biggest difference was found for elagic acid and homovanillic acid (357 \u00b1 50% vs. 1689 \u00b1 293% enhancement). These findings suggest that the predictive value of individual redox profiles of phenolics is limited for the calculation of the experimental effect of their binary mixtures on the UPE of the Fe2+\u2013EGTA\u2013H2O2 system. We hypothesize that polyphenol polymerization may be responsible for this phenomenon.<\/jats:p>","DOI":"10.3390\/molecules30112269","type":"journal-article","created":{"date-parts":[[2025,5,22]],"date-time":"2025-05-22T10:24:45Z","timestamp":1747909485000},"page":"2269","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["A Modified Fenton\u2019s System Fe2+\u2013EGTA\u2013H2O2 Reveals That Redox Activities of Simple Polyphenols Are Suppressed in Binary Mixtures"],"prefix":"10.3390","volume":"30","author":[{"given":"Micha\u0142","family":"Nowak","sequence":"first","affiliation":[{"name":"Radiation Protection, University Hospital No. 2, Medical University of Lodz, Zeromskiego 113, 90-549 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krzysztof","family":"Sasak","sequence":"additional","affiliation":[{"name":"Department of Medical Imaging Techniques, Medical University of Lodz, Lindleya 6, 90-131 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna","family":"Wlodarczyk","sequence":"additional","affiliation":[{"name":"Department of Sleep Medicine and Metabolic Disorders, Medical University of Lodz, Mazowiecka 6\/8, 92-215 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Izabela","family":"Grabska-Kobylecka","sequence":"additional","affiliation":[{"name":"Department of Clinical Physiology, Medical University of Lodz, Mazowiecka 6\/8, 92-215 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Agata","family":"Sarniak","sequence":"additional","affiliation":[{"name":"Department of Clinical Physiology, Medical University of Lodz, Mazowiecka 6\/8, 92-215 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3445-6930","authenticated-orcid":false,"given":"Dariusz","family":"Nowak","sequence":"additional","affiliation":[{"name":"Department of Clinical Physiology, Medical University of Lodz, Mazowiecka 6\/8, 92-215 Lodz, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"270","DOI":"10.4161\/oxim.2.5.9498","article-title":"Plant polyphenols as dietary antioxidants in human health and disease","volume":"5","author":"Pandey","year":"2009","journal-title":"Oxid. 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