Synthesis and Free Radical Scavenging Activity of Coumarin Derivatives Containing a 2‐Methylbenzothiazoline Motif

Abstract

Coumarin and benzothiazole scaffolds can be found in a number of natural or synthetic antioxidants. In an effort to develop a novel radical scavenger and potential antioxidant, a series of coumarin derivatives containing 2-methylbenzothiazoline motif and related compounds was synthesized and evaluated for their DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS(•+) (2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radicals scavenging activities. Among them, 7-hydroxy-3-(2-methyl-2,3-dihydrobenzo[d]thiazol-2-yl)-2H-chromen-2-one (3e) has shown a significant free radical scavenging activity. From the structure-activity point of view, it was found that phenolic coumarin ring and benzothiazoline moiety in target compounds may contribute to the scavenging activity against free radicals.

A comprehensive review in current developments of benzothiazole-based molecules in medicinal chemistry

“…BTA derivatives exhibits some antidiabetic activities and are discussed in this sectionJeon et al, have synthesized BTA-thiazolidinediones conjugated with various lengths of alkyl chains on the exocyclic nitrogen andthen evaluated for their peroxisome proliferator-activated receptor-g. Compound (206), which was substituted with a methyl on the exocyclic nitrogen, was the most potent PPARg agonist. SAR study reveals; the lengthening of the N-alkyl substituent of BTAthiazolidinediones lowered the activation of PPARg but increased the inhibitory action of NO production [240].…”

“…Interestingly, among this series of compounds, (176) evidensed a significant free radical scavenging activity. SAR studies reveals, the eOH present in the coumarin ring enhance the scavenging activity against free radicals [206]. Pyrazolyl-BTA derivatives (177) displayed good antioxidant activity, compounds with trihydroxy substituent was found potent antioxidant [207].…”

Microwave‐Assisted Synthesis and Biological Evaluation of Some Benzimidazole Derivatives Containing a 1,2,4‐Triazol Ring

“…ABTS is a free and stable radical cation, which is able to react with antioxidants [26]. ABTS is a free and stable radical cation, which is able to react with antioxidants [26].…”

Fe3O4‐supported Schiff‐base copper (II) complex: A valuable heterogeneous nanocatalyst for one‐pot synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives

“…[28][29][30] Easy magnetic separation of the MNPs-supported catalysts from the reaction mixtures enables convenient purification avoiding expensive centrifugation or conventional filtration methods. [42][43][44][45] Therefore, these reactions provide the scientists an efficient, time saving and atom economical approach to a wide variety of organic and bioorganic molecules including heterocyclic compounds. In recent years, magnetic Fe 3 O 4 nanoparticles have attracted much attention as privileged supports for immobilization of various catalysts due to their specific properties such as nontoxicity, easy preparation, low cost, good stability, and high surface-area.…”