The antioxidant activity of polysulfides: it's radical!

Abstract

Sulfurized olefins (polysulfides) containing four (or more) sulfur atoms react efficiently with peroxyl radicals by homolytic substitution, accounting for their primary antioxidant activity.

Effects of ethylthiosulfanylate and chromium (VI) on the state of pro/antioxidant system in rat liver

“…According to the literature, the sulfoether group, which is part of ethylthiosulfanylate, has antioxidant properties and is involved in the reduction processes of LHP [20] and this may be the reason of the decrease of the intensity of Cr(VI)-induced lipid peroxidation processes. It is known that compounds with sulfur atoms induce the process of lipid hydroperoxides decomposition into non-radical products [21]. Sulfur-containing compounds have the ability to inhibit the activity of the xanthine-xanthine oxidase system and attenuate ROS-induced lipids and proteins peroxidation [22].…”

Quinone methide dimers lacking labile hydrogen atoms are surprisingly excellent radical-trapping antioxidants

“…Thus, the QMDs add to a short list of molecules which lack labile H-atoms but are nevertheless reactive RTAs. Two of the few other examples of which we are aware are tetrasulfides 32 and trisulfide-1-oxides. 33 These compounds undergo concerted (bimolecular) homolytic substitution by peroxyl radicals to produce stable and persistent perthiyl radicals that do not propagate the autoxidation, but combine to give tetrasulfides.…”

“…1-Hexadecene and cumene were purified and stored as previously described. 8 , 32 The synthesis, purification, and characterization of substituted stilbenes ( 1 ), QMDs ( 2 ), and quad A analogues ( 3 ) as well as hybrid phenol–QMs ( 5 and 6 ) used in this study are described in previous reports. 5 , 6 The synthesis, purification, and characterization of 4a , 37 4a-H 2 O , 38 4b 39 and S4 40 were carried out according to literature reports.…”

Decarboxylative thiolation of redox-active esters to free thiols and further diversification

“…Disulfides are important motifs in life and biological active molecules, due to their unique pharmacological and physiochemical properties 61 – 66 . To further explore the scope of this transformation, more diaryl disulfide-trapping agents were examined with dihydrocinnamic acid-derived ester 1 as a model substrate.…”