In vitro scavenging activity for reactive oxygen species by N‐substituted indole‐2‐carboxylic acid esters

Abstract

The hydroxyl radical (HO*)- and superoxide anion radical (O* (2))-scavenging activity, as well as the singlet oxygen ((1)O(2))-quenching property of N-substituted indole-2-carboxylic acid esters (INDs) were investigated by deoxyribose degradation assay, a chemiluminescence method and the electron spin resonance (ESR) spin-trapping technique. This novel group of compounds was developed as a search for cyclooxygenase-2 (COX-2)-selective enzyme inhibitors. The results obtained demonstrated that of the 16 compounds examined, five inhibited light emission from the superoxide anion radical (O* (2))-DMSO system by at least 60% at a concentration of 1 mmol/L, nine prevented the degradation of deoxyribose induced by the Fenton reaction system (range 3-78%) or scavenged hydroxyl radicals (HO*) directly (range 8-93%) and 14 showed the (1)O(2)-quenching effect (range 10-74%). These results indicate that majority of the indole esters tested possess the ability to scavenge O(-) (2) and HO radicals and to quench (1)O(2) directly, and consequently may be considered effective antioxidative agents.

Conformational and stereoelectronic investigation of tryptamine. An AIM/NBO study

“…Furthermore TRA, as others indolic compounds are very efficient antioxidants, protecting both lipids and proteins from peroxidation, and it is known that the indole structure influences their antioxidant efficacy in biological systems [1][2][3][4]. Radical scavenging by indolic compounds is strongly modulated by their functional residues.…”

Oxidation of benzoins to benzils in the presence of porphyrin sensitizers by air and sunlight or visible light

“…For the m-THPC (5,10,15,20-tetra(m-hydroxyphenyl)chlorin) sensitizer, the singlet oxygen lifetime in DMSO is 19 ls compared to 65 ls in CH 3 CN [97]. According to the literature, DMSO, H 2 O, CH 3 OH, C 2 H 5 OH and DMF are singlet oxygen quenchers [98][99][100]. In addition, it is confirmed that the lifetime of 1 O 2 in acetonitrile is high.…”

Organotypical vascular model for characterization of radioprotective compounds: Studies on antioxidant 2,3-diaryl-substituted indole-based cyclooxygenase-2 inhibitors

“…Recently, we developed a series of novel coxibs based on a 2,3-diarylsubstituted indole chemical lead with high affinity and selectivity for COX-2 as important templates for radiotracer design [33,37]. Obviously, the dual benefit of indole scaffolds providing both a COX-2 pharmacophore and an antioxidant pharmacophore is of particular interest to us and others [34,37,51]. In this regard, the novel 2,3-diaryl-indole coxibs were shown to substantially decrease the formation of lipid and protein oxidation products in a low density lipoprotein oxidation model [37].…”