New Thiosemicarbazides and 1,2,4-Triazolethiones Derived from 2-(Ethylsulfanyl) Benzohydrazide as Potent Antioxidants

Abstract

New thiosemicarbazide derivatives 2-6 were synthesised by reacting 2-(ethylsulfanyl)benzohydrazide with various aryl isothiocyanates. The cyclisation of compounds 2-6 under reflux conditions in a basic medium (aqueous NaOH, 4 N) yielded compounds 7-11 that contain a 1,2,4-triazole ring. All of the synthesised compounds were screened for their antioxidant activities. Compounds 2, 3, and 7 showed better radical scavenging in a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, with IC 50 values of 1.08, 0.22, and 0.74 µg/mL, respectively, compared to gallic acid (IC 50 , 1.2 µg/mL). Compound 3 also showed superior results in a ferric reducing antioxidant power (FRAP) assay (3054 µM/100 g) compared to those of ascorbic acid (1207 µM/100 g).

Synthesis of the Hydrazones of 2‐((3,5‐Di‐tert‐butyl‐4‐hydroxybenzyl)thio) acetohydrazide and the Study of their Radical Scavenging Activity by the DPPH Assay and the Computational Method

“…A similar result was reported by Nazarbahjat, et al . and Lone et al ., in which the compounds with halogen substituents on the para ‐position had good DPPH IC 50 values …”

“…Both values were calculated using DFT. The SD values of the radical compounds were obtained by calculating the Mulliken population analysis using DFT …”

“…A similar result was reported by Nazarbahjat, et al and Lone et al, in which the compounds with halogen substituents on the para-position had good DPPH IC 50 values. 33,34 Prediction of Radical Scavenging Activity Using a Computational Method. One of the pathways in which antioxidants can play a radical scavenger role is H-atom transfer.…”

“…The SD values of the radical compounds were obtained by calculating the Mulliken population analysis using DFT. 33 There were two sites for compounds 4-10, OH-1 and NH, and three for compound 11, OH-1, NH, and OH-2, that might have the capability of donating an H atom ( Figure 6). The BDE and SD values were calculated for each site.…”

Synthesis and Antibacterial Screening of 1-(2-(2-Chlorophenyl)-2-(4-(6-Fluorobenzo[d]isoxazol-3-Yl)piperidin-1-Yl) Containing 1,3,4-Thiadiazole, 1,2,4-Triazole and 1,3,4-Oxadiazole Derivatives

“…In recent years compounds containing benzo [d]isoxazole scaffold attracts many researchers due to their pharmacological activities. Benzo [d]isoxazole and their derivatives are associated with antitubercular 1 , antimycobacterial 2 , anti-inflammatory 3 , antidiabetic 4 and c-Met kinase inhibitor 5 6 , cathepsin L inhibitors 7 , metallo-β -lactamase inhibitors 8 etc activities.…”