The influence of triphenylantimony(V) catecholate and its spiroendoperoxide on lipid peroxidation

Abstract

The effects of triphenylantimony(V) catecholate Ph 3 Sb(Cat) (1) and its spiroendoperoxide Ph 3 Sb(L-O 2 ) (2) (Cat = 3,6-di-tert-butyl-4,5-dimethoxycatecholate) on lipid peroxidation (LP) in vitro and in vivo were examined in BALB/c line mice. A comparative study of the impact of compounds 1 and 2 on LP under similar conditions was made by measuring the formation of thiobarbituric acid reactive substances (TBARS). The anti-or pro-oxidant action of complexes 1 and 2 may be caused by the different redox level of the ligand acting as radical scavenger and/or by the bound molecular oxygen promoting the oxidation process. Biological experiments (in vitro and in vivo) were performed using mouse tissue homogenates. Decreasing TBARS concentration was observed in all examined tissues and blood serum (in vitro as well as in vivo) for catecholate 1. These results indicate inhibition of LP in the presence of complex 1. In contrast to 1, spiroendoperoxide 2 increases the level of TBARS in tissue homogenates. Minor fluctuations of TBARS concentration in erythrocytes and in blood serum indicate the absence of an obvious anti/pro-oxidant influence of 2 on the LP process in vivo. The role of catecholate fragment was found to be essential in explaining antioxidant properties.

Triphenylantimony(V) Catecholates of the Type (3-RS-4,6-DBCat)SbPh3-Catechol Thioether Derivatives: Structure, Electrochemical Properties, and Antiradical Activity

“…We have previously shown that triarylantimony (V) complexes with catecholate ligands act as effective traps and can not only intercept molecular oxygen, but also neutralize alkylperoxy radicals and DPPH, promote the destruction of hydroperoxides, and inhibit lipid peroxidation processes [ 75 , 76 , 77 , 78 , 79 , 80 ]. In the continuation of our research, it was interesting to evaluate the effect of the RS group on the radical scavenging activity in the reaction with the stable DPPH radical.…”

“…In contrast to the transition metals, the O 2 binding does not lead to a change in the antimony oxidation state, while the redox active ligand is involved in the redox reaction. The nature of functional groups in redox active ligands [ 65 , 66 , 67 , 68 ], as well as in substituents at a central antimony atom [ 69 , 70 , 71 , 72 , 73 , 74 ], affects the redox properties of antimony catecholates and their antioxidant activity [ 75 , 76 , 77 , 78 , 79 , 80 ]. Electron-donating groups in catecholate or at the antimony atom in complexes of the type CatSbR 3 shift the oxidation potential to the anodic region.…”

Four-Electron Reduction of O2 Using Distibines in the Presence of ortho-Quinones

“…Interestingly, when carried out in air, this chemistry may also involve O 2 . Indeed, as demonstrated by Cherkasov et al, stiboranes resulting from the reaction of Ph 3 Sb with certain ortho -quinones may fixate O 2 to form semiquinone (SQ) peroxide adducts of type E , in which the O 2 2– unit bridges the antimony center and one of the carbon atoms of the ligand . One of the simplest examples of such a compound is E phenSQ/Ph , obtained by the reaction of Ph 3 Sb and 9,10-phenanthraquinone (phenQ) in air.…”

Binuclear Triphenylantimony(V) Catecholates through N-Donor Linkers: Structural Features and Redox Properties

“…Triarylantimony(V) o-amidophenolates [ 47 , 48 ], as well as some triarylantimony(V) catecholates with electron-donor substituents [ 49 , 50 , 51 ], represent the first class of main group metal complexes, which can bind the molecular oxygen in a reversible manner. The related antimony(V) catecholates were found to be active in a radical scavenging [ 52 , 53 , 54 ], can be considered prospective inhibitors of oxidation processes, such as lipid peroxidation [ 55 , 56 ]. The modification of molecular structure and redox-properties of triorganylantimony(V) catecholates is possible via the use of different donor/acceptor substituents in a redox-active ligand [ 50 , 57 ], at organic groups bound to antimony [ 58 , 59 , 60 ], or coordination of a neutral or ionic ligand to the central antimony atom [ 61 , 62 , 63 ].…”