1,2,3-Triazolyl Phenylhydrazones as Antioxidant Agents: An Ultrasound Promoted Catalyst-Free Synthesis and Molecular Docking Study

An efficient, ultrasound assisted catalyst-free, green protocol has been developed for the synthesis of 1,2,3-triazolyl phenylhydrazone derivatives under environmentally benign condition. The antioxidant activity for all the synthesized derivatives were evaluated in vitro by using 1,1-diphenylpicrylhydrazyl (DPPH) radical scavenging method. The compounds 6a, 6e, 6f, and 6i were shows an excellent antioxidant activity than the standard drug butylated hydroxy toluene with IC50 values in the range 12.03 ± 0.11–14.07 ± 0.31 µg/mL. Molecular docking study was also performed to elaborate their possible interactions with Myeloperoxidase enzyme. Furthermore, in silico ADME properties for all the compounds were also studied. </p

A facile synthesis of quinoxalines by using SO₄²⁻/ZrO₂-TiO₂ as an efficient and recyclable heterogeneous catalyst

Quinoxaline derivatives have been synthesized in good to excellent yields by the cyclocondensation reaction of o-pheneylenediamine with substituted phenacyl bromides/benzil in the presence of SO42−/ZrO2-TiO2 as an efficient and heterogeneous catalyst. The catalyst can be recovered up to five catalytic cycles without significant loss in catalytic activity. The reported SO42−/ZrO2-TiO2 catalyst has been thoroughly characterized by using infrared spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD). Here, we have used ethanol as a green solvent in this cyclocondensation. This new method has several advantages, such as excellent yields, short reaction time, nontoxic, and easily recoverable catalyst.</p

Synthesis, bioevaluation and molecular docking study of new piperazine and amide linked dimeric 1,2,3-triazoles

In search of more potent new antitubercular agents, a library of novel piperazine tethered dimeric 1,2,3-triazoles were designed by assembling 1,2,3-triazoles and piperazine in a single molecular architectural framework. The titled compounds (3a–m) were synthesized by 1,3-dipolar cycloaddition of 1,4-di(prop-2-yn-1-yl)piperazine (1) and various azides (2a–m) using click chemistry approach with good yields. All the synthesized compounds (3a–m) have been screened for their in vitro antitubercular, antifungal and antioxidant activities against their respective strains. Among them, 3b, 3d, and 3i have revealed promising antitubercular activity against Mycobacterium tuberculosis (Mtb) H37Rv with MIC 12.5 µg/mL. Molecular docking results provided well-clustered solutions to the mode of binding for these molecules into the active site of Mtb enoyl reductase (InhA). In addition to this, most of synthesized compounds were found to have potential antifungal as well as antioxidant activity.</p

Meglumine Sulfate: An Efficient Catalyst for the Synthesis of Quinoxalines

Meglumine Sulfate: An Efficient Catalyst for the Synthesis of Quinoxaline

Theophylline Hydrogen Sulfate: A green and efficient catalyst for synthesis of 3,3-bis(1<i>H</i>-indol-3-yl)indolin-2-one derivatives

A new green protocol for the synthesis of 3,3-bis(1H-indol-3-yl)indolin-2-one derivatives by reacting isatin with indole in the presence of Theophylline Hydrogen Sulfate as a new solid acid, a highly effective and reusable catalyst. This reaction was carried out by using aqueous ethanol as a solvent system at room temperature with constant stirring. A highly effective solid acid catalyst, short reaction time, better to excellent yields of the products, safe and environmentally benign reaction conditions are some of the benefits of the present synthetic method.</p

DTP/SiO₂ Assisted Synthesis of New Benzimidazole-Thiazole Conjugates Targeting Antitubercular and Antioxidant Activities

A series of new substituted benzimidazole-thiazoles (9a–l) have been designed and synthesized using 2-aminothiazole as a starting material by using molecular hybridization approach. The newly synthesized compounds were characterized by 1H NMR, 13C NMR and HRMS analyses. The compounds (9a–l) were evaluated for their in vitro antitubercular activity against Mtb (MTCC 300) strain. Among the screened compounds 9a, 9b, 9c and 9d have displayed promising antitubercular activity with MIC 7.55, 4.60, 15.39 and 28.38 μg/mL, respectively. All the compounds were further evaluated for their DPPH radical scavenging activity. The compounds 9a, 9b and 9d were exhibited excellent radical scavenging activity. In addition to this, single crystal structure of compound 9a was also studied. Furthermore, the high potency of these molecules was supported by ADME properties prediction as well as molecular docking study to gain an insight into the binding mode and affinity toward mycobacterial InhA.</p

Synthesis of New Amide Linked Biphenoloxy 1,2,3-Triazoles as Antitubercular and Antimicrobial Agents

New 1,2,3-triazoles bearing biphenoloxymethyl and acetanilido moieties (5a-5l) have been synthesized, starting from 4-phenylphenol (1) following click chemistry approach. The synthesized compounds have been thoroughly characterized by their 1H NMR, 13C NMR and HRMS spectral data. These compounds were evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv and antimicrobial activity against pathogenic microbia. Among the screened compounds, 5a and 5i have displayed notable antitubercular activity with MIC 25 µg/mL. Compounds 5a, 5b, 5c, 5 g, 5i and 5 l have shown effective inhibition against most of tested pathogens. Molecular docking results of compounds 5a and 5i show the binding modes of the synthesized compounds into the active site of mycobacterial enoyl reductase. The synthesized compounds have also been analyzed for their ADME properties. By considering all these results, the present research work will offer a promising lead series for discovery of emerging potent antitubercular agents.</p