Schiff bases of 4-(methylthio)benzaldehydes: Synthesis,characterization, antibacterial, antioxidant and cytotoxicity Studies

Abstract

A series of new Schiff bases of 4-(methylthio)benzaldehyde derivatives 3(a-i) were synthesized by the reaction of 4-(methylthio)benzaldehyde with various amines 2(a-i). Newly synthesized compounds were characterized by elemental analyses, UV-visible, FT-IR, Mass and 1 H NMR spectral studies. All compounds were evaluated for their in vitro antibacterial activity against clinically isolated strains i.e., E. Coli, P. Fluorescence, M. Luteus and B. Subtilis. These compounds were screened for their antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl (DPPH • ) and ferrous ion chelating assay (Fe 2+ ) methods. The cytotoxicity assay was performed by tryphan blue dye exclusion method. Compounds 3g, 3h and 3i exhibited good antibacterial activity when compared with other compounds in the series against tested pathogenic bacterial strains. All the compounds showed antioxidant activity, where compound 3b was the best radical scavenger and Fe 2+ ion scavenger. These findings showed that the Schiff bases of 4-(methylthio)benzaldehyde derivatives possess antioxidant activity with different mechanism of actions towards the different free radicals tested. Among these derivatives, 3b and 3h had the strongest activity against human peripheral lymphocytes.

Neurolocomotor Behavior and Oxidative Stress Markers of Thiazole and Thiazolidinedione Derivatives against Nauphoeta cinerea

“…In relation to our results of free iron levels, a significant reduction was observed in connective tissue homogenates of N. cinerea after treatment with NW05 (10 mM) e NJ20 (10 mM) ( Figure 6 ). It has been reported that certain thiazoles have excellent free Fe 2+ chelating capacity and moderate toxicity, which could justify the results found here [ 60 ].…”

Paullinia cupana (Kunth) stimulates behavior patterns and regulates oxidative stress markers in lobster cockroach Nauphoeta cinerea

“…Finally, in addition to lipid peroxidation, it was observed here depletion in free Fe 2+ ion contents in N. cinerea head homogenates for all concentrations of guarana powder decoction (Figure 11), which might as well infer the potential antioxidant capacity of P. cupana. Indeed, substances capable of chelating free iron are categorized as antioxidant compounds, broadly used in toxic-pharmacological studies (Karthik et al, 2016;Schneider et al, 2019). Similar to our results, Pereira et al (2022) reported a significant reduction in Fe 2+ ion content in connective tissue homogenates of N. cinerea after treatment with Thiazolidine compounds NW05 (10 mM) e NJ20 (10 mM).…”

Substituted 4-Acyl-5-methyl-2-phenyl-pyrazol-3-one-phenylhydrazones with Antioxidant Properties: X-Ray Crystal and Spectroscopic Studies

“…Interesting antioxidant activities have been exhibited by the reported phenylhydrazones compared to the standard drug, vitamin C. A progressive increase in the percentage antioxidant activity with increasing concentration of test compounds as depicted in Table 2 and Figure 7 was recorded [17]. Based on the calculated IC 50 values, Prmpp-Ph has shown a stronger antioxidant property overall, with an IC 50 value of 175.66 g/ml followed by Empp-Ph with an IC 50 of 193.90 g/ml.…”

“…Tridentate 3-formyl chromone Schiff bases showed good antioxidant activities against DPPH at different concentrations with as low as 1.27 g/ml IC 50 value compared to standard drug BHT (IC 50 value of 0.67 g/ml) [16]. More recently, Karthik and fellow researchers synthesized a series of Schiff bases with 4-(methylthio)benzaldehydes that have shown to highly scavenge free radicals [17]. Acylpyrazolone Schiff bases synthesized from the condensation reaction of some acylpyrazolone derivatives with sulfanilamide that showed antioxidant properties have been reported by our group [18].…”