New quinoline-triazole conjugates: Synthesis, and antiviral properties against SARS-CoV-2.

At present therapeutic options for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are very limited. We designed and synthesized three sets of small molecules using quinoline scaffolds. A series of quinoline conjugates (10a-l, 11a-c, and 12a-e) by incorporating 1,2,3-triazole were synthesized via a modified microwave-assisted click chemistry technique. Among the synthesized conjugates, 4-((1-(2-chlorophenyl)-1H-1,2,3-triazol-4-yl)methoxy)-6-fluoro-2-(trifluoromethyl)quinoline (10g) and 6-fluoro-4-(2-(1-(4-methoxyphenyl)-1H-1,2,3-triazol-4-yl)ethoxy)-2-(trifluoromethyl)quinoline (12c) show high potency against SARS-CoV-2. The selectivity index (SI) of compounds 10g and 12c also indicates the significant efficacy compared to the reference drugs.

An Efficient Greener Approach for N-Acylation of Amines in Water Using Benzotriazole Chemistry.

A straightforward, mild and cost-efficient synthesis of various arylamides in water was accomplished using versatile benzotriazole chemistry. Acylation of various amines was achieved in water at room temperature as well as under microwave irradiation. The developed protocol unfolds the synthesis of amino acid aryl amides, drug conjugates and benzimidazoles. The environmentally friendly synthesis, short reaction time, simple workup, high yields, mild conditions and free of racemization are the key advantages of this protocol.

Development of Isatin-Based Schiff Bases Targeting VEGFR-2 Inhibition: Synthesis, Characterization, Antiproliferative Properties, and QSAR Studies.

Three sets of isatin-based Schiff bases were synthesized utilizing the molecular hybridization approach. Some of the synthesized Schiff bases show significant to moderate antiproliferative properties against MCF7 (breast), HCT116 (colon), and PaCa2 (pancreatic) cancer cell lines with potency compared to reference drugs 5-fluorouracil (5-FU) and Sunitinib. Among all, compound 17 f (3-((1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)imino)-1-((1-(2-methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl)-5-methylindolin-2-one) exhibits promising antiproliferative properties against the MCF7 cancer cell line with 2.1-fold more potency than Sunitinib. However, among all the synthesized compounds, three (5-methylisatin derivatives) were the most effective against HCT116 in comparison to 5-FU. Compound 17 f exhibited the highest anti-angiogenic effect on the vasculature as it significantly reduced BV from 43 mm to 2 mm in comparison to 5.7 mm for Sunitinib and flow cytometry supports the arrest of the cell cycle at G1/S phases. In addition, compound 17 f also showed high VEGFR-2 inhibition properties against breast cancer cell lines. Robust 2D-QSAR studies supported the biological data.

Design, synthesis, antimicrobial, and DNA gyrase inhibitory properties of fluoroquinolone-dichloroacetic acid hybrids.

A series of new fluoroquinolone conjugates 8a-g and 9a-f were synthesized via benzotriazole-mediated synthetic approach with good yield and purity. Some of the synthesized analogs exhibited significant antibacterial properties against Escherichia coli and Staphylococcus aureus with potency higher than that of the parent drugs through in vitro standard bioassay procedure (conjugates 8c and 8d reveal antimicrobial properties with potency 1.9, 61.9, 20.7 and 2.4, 37.1, 8.3 folds relative to the parent antibiotic 6 against E. coli, S. aureus, and Enterococcus faecalis, respectively). The observed experimental data were supported by enzymatic DNA gyrase inhibitory property. Developed BMLR-QSAR model validates the observed experimental data and recognizes the parameters responsible for the enhanced antibacterial properties.