Facile TiO2 NPs catalysed synthesis of substituted-4-Hydroxy/methoxy benzylidene derivatives as potent antioxidant and anti-tubercular agents

Abstract

In this work, we report a facile synthesis of a series of substituted-4-hydroxy/methoxy benzylidene derivatives ( 3a-i ) via Knoevenagel condensation reaction of different active methylene compounds ( 1 ) with 4-hydroxy/methoxy benzaldehyde ( 2 ) under reflux condition in aq. EtOH using catalytic amount of TiO 2 NPs. The structures of all the obtained compounds were confirmed by analytical and spectroscopic methods and screened for their antioxidant and anti-tubercular activities. Antioxidant activity results revealed that, the compound 3e with IC 50 value 105.48 µg/mL showed very effective DPPH scavenging activity and compound 3h with IC 50 value 129.72 µg/mL exhibited most effective nitric oxide radical scavenging activity compared to the reference standard BHT and ascorbic acid respectively. From the results of anti-TB activity, compound 3b displayed a more sensitivity at 25 µg/mL. Furthermore, synthesized compounds were assessed for molecular docking studies on the target enzymes Human peroxiredoxin 5 and enoyl-ACP reductase and they were emerged has an active antioxidant and anti-TB agents with least binding energy -5.8 and -8.0 kJ mol −1 respectively.