Synthesis, spectroscopic characterization, DFT, molecular docking and in vitro antibacterial potential of novel quinoline derivatives

Synthesis of novel sulphonamide derivatives from tunable quinolines with computational studies

The synthesis of new quinoline-sulphonamide derivatives was accomplished through a meticulous five-step molecular assembly utilizing Suzuki, acid-amine cross-coupling reactions and N-alkylation. The integrity of each derivative was thoroughly confirmed via comprehensive spectroscopic analyses, including 1H and 13C NMR, DEPT-135, 1H-1H COSY, HSQC NMR and HRMS techniques. Subsequently, the absorbance and emission spectra of the newly synthesized derivatives were thoroughly investigated. Absorbance spectra were determined to be restricted within the range of 337 nm to 341.73 nm, with compound 10j exhibiting the maximum wavelength of 341.73 nm; conversely, emission spectra were uniformly detected within the range of 411.70 nm to 429.90 nm upon excitation at 340 nm, with compound 10f demonstrating the highest wavelength of 429.90 nm. Notably, these fluorophores displayed impressive characteristics, with high intensity and significant molar extinction coefficients; quantum yield ranging from 0.015 to 0.558 along with the highest stokes shifts in 10h compound (0.6237 × 10-4) in acetonitrile solvent. Additionally, compound 10p showed strong binding affinity and favorable pharmacokinetic properties through molecular docking studies and ADMET calculations. The electronic structure of the molecules was elucidated using techniques such as density functional theory (DFT) and molecular electrostatic potential (MEP) mapping. Additionally, the calculated global reactivity parameters provided valuable insights. Compound 10p exhibited a distinctly low energy gap compared to other compounds, demonstrating its exceptional properties. The comparison between experimental and theoretical UV-vis spectra with major contribution transition in percentage also showcased the remarkable consistency and quality of the synthesized derivatives, highlighting the significant potential of this work in the field of fluorophore and biological application.

Novel diphenyltin(IV) complexes with carboxylato N-functionalized 2-quinolone ligands: Synthesis, characterization and in vitro anticancer studies

Three new diphenyltin(IV) complexes, bis(3-(4-methyl-2-oxoquinolinyl-1(2H)-yl)propanoato)diphenyltin(IV) (1), bis(2-(4-methyl-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (2), and bis(2-(4-hydroxy-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (3), were synthesized and characterized by elemental microanalysis, FT-IR spectroscopy, and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. Crystal structure of ligand precursor, 2-(4-methyl-2-oxoquinolinyl-1-(2H)-yl)acetic acid (HL2), has been determined by X-ray diffraction studies. Asymmetric bidentate coordination of the carboxylato ligands and skew trapezoidal structures are assumed for the synthesized complexes. In vitro anticancer activity of the synthesized diphenyltin(IV) complexes was evaluated against three human: MCF-7 (breast adenocarcinoma), A375 (melanoma), HCT116 (colorectal carcinoma), and three mouse tumor cell lines: 4T1 (breast carcinoma), B16 (melanoma), CT26 (colon carcinoma) using MTT and CV assays. The IC50 values fall in the range from 0.1 to 3.7 μM. Flow cytometric analysis and fluorescent microscopy suggest that complex 1 induces caspase-dependent apoptosis followed with strong blockade of cell division in HCT116 cells. Since complex 1 showed ROS/RNS scavenging potential mentioned cytotoxicity was not connected with oxidative stress.

2-((3-(4-Methoxyphenyl)-4,5-dihydroisoxazol-5-yl)methyl)benzo[d]isothiazol-3(2H)-one1,1-dioxide

In this work, a novel compound N-(3-(4-methoxyphenyl)isoxazolin-5-yl)methylsaccharin has been synthesized. The molecular structure of the compound was determined using various spectroscopic techniques and confirmed by a single-crystal X-ray diffraction analysis. In the single crystal, C–H…O hydrogen bonds between neighboring molecules form chains along the a-axis direction. Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H…H (35.7%), H…O/O…H (33.7%), and H…C/C…H (13%) interactions. The optimized structure calculated using density functional theory at the B3LYP/6–311 G(d,p) level is compared with the experimentally determined structure in the solid state. The calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gap is 4.9266 eV.