Synthesis, spectral characterization, crystal structure and computational investigation of 2-formyl-6-methoxy-3-carbethoxy quinoline as potential SARS-CoV inhibitor.

The recent COVID-19 outbreak caused by the novel coronavirus SARS-CoV-2 has an immense impact on global health and economy. Although vaccines are being used, urgent need of drugs based on natural products with high efficacy and safety is a pressing priority. Quinoline alkaloids are well known for their therapeutic action against malaria; initially, it was tried against Coronaviruses. It is a basic vital scaffold to design drugs with required biological and pharmacological activities. In this present study, a new quinoline compound was synthesized and characterized by spectroscopy techniques. Crystal structure was established by SCXRD analysis and data is used as an input to perform various computations. Additionally, using state-of-the-art quantum computational techniques, the geometry optimization and calculation of UV-Vis spectrum of 2F6M3CQ were performed at B3LYP/6-311G* level of theory. The optimized molecular geometric parameters as well as UV-Vis spectrum values are found to be in good agreement with their respective experimental results. The visualization of 3-D plots of FMO and MEP indicated the structure and reactivity trends of 2F6M3CQ molecule. Molecular docking methods were utilized to find the drug ability of 2F6M3CQ with Mproprotein of SARS-CoV-2. There were many intermolecular interactions between Mpro protein and 2F6M3CQ molecule which lead to good binding energy (-5.5 kcal/mol) between them which was found to be better than the binding energy of chloroquinine molecule (-4.5 kcal/mol) as studied under same docking protocols. Finally, drug likeness and ADME properties of 2F6M3CQ were also analyzed. There is no violation found for RO5 in our 2F6M3CQ compound. ADME analysis shows drug like properties of compound 2F6M3CQ which predicts that it might be a potential candidate for inhibition of SARS-CoV-2.

Hydrogen bonded charge transfer molecular salt (4-chloro anilinium-3-nitrophthalate) for photophysical and pharmacological applications.

Radical scavenging activity against DPPH radical and binding properties of a hydrogen bonded charge transfer molecular salt 4-chloro anilinium-3-nitrophthalate(CANP) with calf thymus DNA has been studied by electronic absorption and emission spectroscopy. The molecular structure and crystallinity of the CANP salt have been established by carried out powder and single crystal X-ray diffraction analysis which indicated that cation and anion are linked through strong N+H…O- type of hydrogen bond. FTIR spectroscopic study was carried out to know the various functional groups present in the crystal. 1H and 13C NMR spectra were recorded to further confirm the molecular structure of the salt crystal. The thermal stability of the title salt was established by TG/DTA analyses simultaneously on the powdered sample of the title crystal. Further, the CANP salt was examined against various bacteria and fungi strains which showed a remarkable antimicrobial activity compared to that of the standards Ciproflaxin and Clotrimazole. The results showed that the CANP salt could interact with CT-DNA through intercalation. Antioxidant studies of the substrates alone and synthesized CANP salt showed that the latter has been better radical scavenging activity than that of the former against DPPH radical. The third order nonlinear susceptibility of the CANP salt was established by the Z-scan study.

Pharmacological investigation of 2-aminobenzothiazolium-4-methylbenzenesulphonate: Synthesis, spectral characterization and structural elucidation.

An organic charge transfer complex, 2-aminobenzothiazolium-4-methylbenzenesulphonate (ABPTS) was synthesized and single crystals grown by slow solvent evaporation solution growth technique at ambient temperature. The single crystal X-ray diffraction analysis was carried out to establish the molecular structure of the title crystal. FT-IR spectral study was carried out to identify the various functional groups present in the crystal. The (1)H and (13)C spectra were recorded to further confirm the molecular structure of the CT complex. The TG/DTA analyses were carried out to establish the thermal stability of the complex. The antibacterial and antifungal activities of synthesized complex were examined against various bacteria and fungi strains, to identify the antibacterial and antifungal activity. The DNA binding profile of the complex has been investigated through absorption spectroscopy and complex has intrinsic binding constant 3.6 × 10(4) M(-1). A gel electrophoresis assay demonstrated the ability of the complex to cleave the pBR322 DNA. The free radical scavenging activity of the complex has been determined against DPPH, OH and ABTS radicals.