biostudies-literatureUnknown10(19)Chauvin JRNatural Sciences and Engineering Research Council of CanadaCanada Foundation for InnovationOlefin sulfurization, wherein alkenes and sulfur are heated together at high temperatures, produces branched polysulfides. Due to their anti-wear properties, they are indispensible additives to lubricants, but are also added to other petroleum-derived products as oxidation inhibitors. Polysulfides also figure prominently in the chemistry and biology of garlic and other plants of the <i>Allium</i> species. We previously reported that trisulfides, upon oxidation to their corresponding 1-oxides, are surprisingly effective radical-trapping antioxidants (RTAs) at ambient temperatures. Herein, we show that the homolytic substitution mechanism responsible also operates for tetrasulfides, but not trisulfides, disulfides or sulfides. Moreover, we show that this reactivity persists at elevated tempeChemical science4999-5010https://www.ebi.ac.uk/biostudies/studies/S-EPMC6524666biostudies-literatureThe antioxidant activity of polysulfides: it's radical!PMC6524666Chauvin JRGriesser MPratt DAfalseThe antioxidant activity of polysulfides: it's radical!Olefin sulfurization, wherein alkenes and sulfur are heated together at high temperatures, produces branched polysulfides. Due to their anti-wear properties, they are indispensible additives to lubricants, but are also added to other petroleum-derived products as oxidation inhibitors. Polysulfides also figure prominently in the chemistry and biology of garlic and other plants of the <i>Allium</i> species. We previously reported that trisulfides, upon oxidation to their corresponding 1-oxides, are surprisingly effective radical-trapping antioxidants (RTAs) at ambient temperatures. Herein, we show that the homolytic substitution mechanism responsible also operates for tetrasulfides, but not trisulfides, disulfides or sulfides. Moreover, we show that this reactivity persists at elevated tempe2019-01-01T00:00:00Z2019 May2026-05-07T11:04:03.671Z2019-07-24T07:02:15ZS-EPMC65246663118304910.1039/c9sc00276f