Crystal structure, spectroscopic and electronic features of 6-(Chloromethyl)uracil

Chitosan-based Schiff base polymer derived from acetyl triazolyl uracil: Synthesis, characterization, evaluation of antimicrobial and antioxidant activities, and density functional theory calculations

This work aimed to synthesize a new acetyl triazolyl uracil (UT) compound and subsequently utilize it to obtain a new chitosan-based Schiff base polymer (CH-UT). The new derivative was characterized using elemental analysis, FTIR, 1H NMR, XRD, TGA, DSC, and SEM analyses. Both UT and CH-UT were evaluated for their antibacterial activities against various Gram-positive and Gram-negative bacteria. The results demonstrated that the CH-UT displayed significant antibacterial activity against E. coli and L. monocytogenes, with inhibition ability of 44 % and 53 %, respectively, and low minimum inhibitory concentration (MIC) values of 31 μg/mL for E. coli and 15 μg/mL for L. monocytogenes. Additionally, the biofilm inhibitory activity showed that chitosan alone reduced E. coli biofilms by 10.25 %, whereas the combination of chitosan with UT in CH-UT increased inhibition to 43.00 %. The maximum biofilm inhibition for S. aureus was 42.02 % with UT alone, surpassing both chitosan and CH-UT. Furthermore, the CH-UT derivative showed notable antioxidant activity, with a value of 72.76 %. Results from frontier molecular orbitals (FMOs) analysis indicated that CH-UT exhibits higher reactivity due to its lower HOMO-LUMO energy gap and modified structure. The triazole group in CH-UT contributes to its potential antibacterial activity through hydrogen bonding and electronic properties.

Synthesis, structural, spectral, antioxidant, bioactivity and molecular docking investigations of a novel triazole derivative

The structural, spectroscopic and electronic properties of 4-(4-nitrophenyl)-5-(pyridin-3-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione have been analyzed by using single crystal X-ray diffraction (SCXRD), ¹H and ¹³C NMR chemical shifts and FT-IR spectroscopic methods both theoretically and experimentally. The tautomeric (thiol and thione) energetic analysis results, structural optimization parameters (bond lengths and angles), vibrational wavenumbers, proton and carbon NMR chemical shifts, UV-Vis. parameters, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) analyses and Molecular Electrostatic Potential (MEP) surface have been calculated by using DFT/B3LYP quantum chemical method with 6-311++G(2d,2p) basis set to compare with the experimental results. The computed geometry parameters, vibrational wavenumbers, and NMR chemical shifts have been in good agreement with the experimental results. It should be noted that the radical scavenging activities of the title compound have been evaluated by using different test methods i.e. 2,2-Diphenyl-1-picrylhydrazyl (DPPH), N,N-dimethyl-p-phenylenediamine (DMPD) and 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS). According to obtained results, the title compound displayed DPPH (SC₅₀ 19.42 ± 0.11 μg/mL), DMPD (SC₅₀ 21.13 ± 0.08 μg/mL) and ABTS (SC₅₀ 38.17 ± 0.25 μg/mL) scavenging activities. Also, these results have been compared with Butylated hydroxyanisole (BHA), Rutin (RUT) and Trolox (TRO) used as standard compounds. The physicochemical, pharmacokinetic, and toxicity features of the compound have been determined by using drug-likeness and in silico ADMET investigations. The interaction results with SARS-CoV-2 main protease (M^pro) of the title ligand compound have been analyzed via the help of molecular docking study.Communicated by Ramaswamy H. Sarma.