Design, Synthesis, Biological Evaluation and Molecular Docking Studies of 1,4-Disubstituted 1,2,3-Triazoles: PEG-400:H2O Mediated Click Reaction of Fluorescent Organic Probes under Ultrasonic Irradiation

Abstract

The perpetual demand of medicinally significant scaffolds has prompted the synthetic chemists to identify simple and efficient routes for flawless synthesis. A PEG-400:H2O mediated highly versatile, efficacious and selective “Click reaction” of fluorescent organic Probes under ultrasonic irradiation is reported. 1,2,3-Triazole ring has also been revealed to play a crucial role in bioorthogonal methodologies, fragment-based drug design, and biomolecular mimetics. This methodology provides a rapid and efficient approach for the synthesis of 1,4-Disubstituted 1,2,3-triazoles under Copper (I)-Catalyzed Azide-Alkyne [3 + 2] Cycloaddition (CuAAC) conditions in good to excellent yields in less time. This synthetic protocol has been proven to endorse easy work-up under benign reaction conditions. The green solvent system employed has been efficaciously reused several times without any loss of its activity in an aqueous medium. All the title compounds were characterized by using elemental analysis, 1HNMR, 13CNMR, FTIR, and mass spectral data. The newly synthesized compounds were biologically evaluated for their antioxidant activity. The antioxidant activity results demonstrate that all compounds showed good to excellent antioxidant activity, particularly the compounds 5d, 8 b, 8c and 8d exhibited promising radical scavenging activity. Further, photophysical properties of the compounds were accomplished using spectrofluorimeter. By this method, compounds 5c, 5e, 5f, 8a, 8 b, 8c and 8d exhibited fluorescence in the visible region. Molecular docking studies suggested the antioxidant activity of synthesized compounds due to the inhibition of neuronal nitric oxide synthase (HnNOS).