1,2,4-triazole-3-thione Schiff bases compounds: Crystal structure, hirshfeld surface analysis, DFT studies and biological evaluation

Synthesis and Antifungal Properties of 1,2,4-Triazole Schiff Base Agents Based on a 3D-QSAR Model

Based on our previous research, a 3D-QSAR model (q2=0.51, ONC=5, r2=0.982, F=271.887, SEE=0.052) was established to predict the inhibitory effects of triazole Schiff base compounds on Fusarium graminearum, and its predictive ability was also confirmed through the statistical parameters. According to the results of the model design, 30 compounds with superior bioactivity compared to the template molecule 4 were obtained. Seven of these compounds (DES2-6, DES9-10) with improved biological activity and readily available raw materials were successfully synthesized. Their structures were confirmed through HRMS, NMR, and single crystal X-ray diffraction analysis (DES-5). The bioactivity of the final products was investigated through an in vitro antifungal assay. There was little difference in the EC50 values between the experimental and predicted values of the model, demonstrating the reliability of the model. Especially, DES-3 (EC50=9.915 mg/L) and DES-5 (EC50=9.384 mg/L) exhibited better inhibitory effects on Fusarium graminearum compared to the standard drug (SD) triadimenol (EC50=10.820 mg/L). These compounds could serve as potential new fungicides for future research. The interaction between the final products and isocitrate lyase (ICL) was investigated through molecular docking. Compounds with R groups that have a higher electron-donating capacity were found to be biologically active.

Design and Synthesis of Antifungal Candidates Containing Triazole Scaffold from Natural Rosin against Valsa mali for Crop Protection

Two series of dehydroabietyl-1,2,4-triazole-4-Schiff-based derivatives were synthesized from rosin to control plant fungal diseases. In vitro evaluation and screening of the antifungal activity were performed using Valsa mali, Colletotrichum orbiculare, Fusarium graminearum, Sclerotinia sclerotiorum, and Gaeumannomyces graminis. Compound 3f showed excellent fungicidal activity against V. mali (EC₅₀ = 0.537 μg/mL), which was significantly more effective than the positive control fluconazole (EC₅₀ = 4.707 μg/mL). Compound 3f also had a considerable protective effect against V. mali (61.57%-92.16%), which was slightly lower than that of fluconazole (85.17-100%) at 25-100 μg/mL. Through physiological and biochemical analyses, the preliminary mode of action of compound 3f against V. mali was explored. Ultrastructural observation of mycelia showed that compound 3f hindered the growth of the mycelium and destroyed the ultrastructure of V. mali seriously. Conductivity analysis and laser scanning confocal microscope staining showed that compound 3f changed cell-membrane permeability and caused accumulation of reactive oxygen species. The enzyme activity results showed that compound 3f significantly inhibited the activity of CYP51 (59.70%), SOD (76.9%), and CAT (67.86%). Molecular docking identified strong interaction energy between compound 3f and crystal structures of CYP51 (-11.18 kcal/mol), SOD (-9.25 kcal/mol), and CAT (-8.79 kcal/mol). These results provide guidance for the discovery of natural product-based antifungal pesticide candidates.

A possible potential COVID-19 drug candidate: Diethyl 2-(2-(2-(3-methyl-2-oxoquinoxalin-1(2H)-yl)acetyl)hydrazono)malonate: Docking of disordered independent molecules of a novel crystal structure, HSA/DFT/XRD and cytotoxicity

This study reports the synthesis, characterization and importance of a novel diethyl 2-(2-(2-(3-methyl-2-oxoquinoxalin-1(2H)-yl)acetyl)hydrazono)malonate (MQOAHM). Two independent molecular structures of the disordered MQOAHM have been established by XRD‑single‑crystal analysis in a ratio of 0.596(3)/0.404(3), MQOAHM (a) and MQOAHM (b), respectively. MQOAHM was characterized by means of various spectroscopic tools ESI-MS, IR, ¹H &¹³C NMR analyses. Density Functional Theory (DFT) method, B3LYP, 6-311++G(d,p) basis set was used to optimize MQOAHM molecule. The obtained theoretical structure and experimental structure were superimposed on each other, and the correlation between them was calculated. The Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) were created, and the energy gap between these orbitals was calculated. For analyzing intermolecular interactions, Molecular Electrostatic Potential (MEP) and Hirshfeld Surface Analysis were studied. For a fair comparative study, the two forms of the title compound were docked together with 18 approved drugs and N3 under precisely the same conditions. The disordered molecule structure's binding scores against 7BQY were -7.0 and -6.9 kcal/mol^-1 for MQOAHM (a) and MQOAHM (b), respectively. Both the forms show almost identical superimposed structures and scores indicating that the disorder of the molecule, in this study, has no obvious effect. The high binding score of the molecule was attributed to the multi-hydrogen bond and hydrophobic interactions between the ligand and the receptor's active amino acid residues. Worth pointing out here that the aim of using the free energy in Silico molecular docking approach is to rank the title molecule compared to the wide range of approved drugs and a well-established ligand N3. The binding scores of all the molecules used in this study are ranged from -9.9 to -4.5 kcal/mol^-1. These results and the supporting statistical analyses suggest that this malonate-based ligand merits further research in the context of possible therapeutic agents for COVID-19. Cheap computational techniques, PASS, Way2drug and ADMET, online software tools, were used in this study to uncover the title compound's potential biological activities and cytotoxicity.

Single crystal X-ray structural and Hirshfeld surface analysis dataset for some isobutyl-1,2,6-triaryl-4-(arylamino)-1,2,5,6-tetrahydropyridine-3-carboxylates

This article reports the single-crystal X-ray diffraction dataset of some isobutyl-1,2,6-triaryl-4-(arylamino)-1,2,5,6-tetrahydropyridine-3-carboxylate (1-3) derivatives with Hirshfeld surface analysis. Pictorial representations of intramolecular hydrogen bonding in 1-3 with the characteristics of Resonance Assisted Hydrogen Bonding (RAHB) are presented. The data corresponding to the Hirshfeld surface analysis is given.