Halogen bonding in the antibacterial 1,2,4-triazole-3-thione derivative – Spectroscopic properties, crystal structure and conformational analysis

New2-((2-(2,4-dinitrophenyl)hydrazineeylidene) derivatives: design, synthesis, in silico, and in vitro anticancer studies

A series of novel hydrazone compounds have been synthesized by the condensation of hydrazines and different substituted salicylaldehydes at a molar ratio of 1:1 in one step reaction and characterized by FT-IR, ESI-MS, 1H NMR, and single crystal x-ray diffraction. The crystal structure of the compound shows a trans configuration around the C = N bond and triclinic system with P -1/-p 1. Synthesized compounds were screened for cytotoxicity activities against A375 (melanoma), HT-29 (Colon), and A549 (lung) cancer cell lines. Among them, compound 2 exhibited the highest cytotoxic effect against the A375 cell line (IC50 = 0.30 µM) and HT-29 cell line (1.68 µM), compared to those of apatinib as a reference standard drug (0.28, 1.49 µM, respectively). The cytocompatibility assay on the L929 normal cell line and the hemolysis assay on human RBC were used to validate the non-toxic action. From DFT calculation, the various parameters such as HOMO-LUMO energies, Hirshfeld, and MEP have been studied. Furthermore, in silico molecular docking with three receptors was studied. Among four compounds, compound 2 has the lowest binding energy against cyclin dependent kinase (ΔGb = -9.3 kcal/mol). In addition to this, molecular dynamics (MD) simulation was also performed. Based on this study, these novel hydrazones can be considered a promising anticancer agent due to their potent cytotoxicity activities and computational analysis.Communicated by Ramaswamy H. Sarma.

Uracil Derivatives for Halogen-Bonded Cocrystals

Among non-covalent interactions, halogen bonding is emerging as a new powerful tool for supramolecular self-assembly. Here, along with a green and effective method, we report three new halogen-bonded cocrystals containing uracil derivatives and 1,2,4,5-tetrafluoro-3,6-diiodobenzene as X-bond donor coformer. These multicomponent solids were prepared both by solvent-drop grinding and solution methods and further characterized by powder and single-crystal X-ray diffraction, Fourier-transformed infrared spectroscopy, and thermal methods (TGA-DSC). In order to study the relative importance of hydrogen versus halogen bonds in the crystal packing, computational methods were applied.

Heterocycle Compounds with Antimicrobial Activity

Background:

Bacterial infections are a growing problem worldwide causing morbidity and mortality mainly in developing countries. Moreover, the increased number of microorganisms, developing multiple resistances to known drugs, due to abuse of antibiotics, is another serious problem. This problem becomes more serious for immunocompromised patients and those who are often disposed to opportunistic fungal infections.

Objective:

The objective of this manuscript is to give an overview of new findings in the field of antimicrobial agents among five-membered heterocyclic compounds. These heterocyclic compounds especially five-membered attracted the interest of the scientific community not only for their occurrence in nature but also due to their wide range of biological activities.

Method:

To reach our goal, a literature survey that covers the last decade was performed.

Results:

As a result, recent data on the biological activity of thiazole, thiazolidinone, benzothiazole and thiadiazole derivatives are mentioned.

Conclusion:

It should be mentioned that despite the progress in the development of new antimicrobial agents, there is still room for new findings. Thus, research still continues.

Symmetry in Recognition of Supramolecular Synthons–Competition between Hydrogen Bonding and Coordination Bond in Multinuclear CuII–4f Complexes with Bicompartmental Schiff Base Ligand

Classic Cu–O coordination bonds in 1 or elongated semi-coordination ones in 2 and 3 were applied to construct CuII–4f complexes composed of trinuclear subunits linked through μ-NO3− ions with formulae given as [Cu2Tm(H2tehy)2]2(NO3)6·H2O, (1), {[Cu2Ho(H2tehy)2(NO3)2][Cu2Ho(H2tehy)2(H2O)2]}(NO3)4·2H2O, (2), and {[Cu2Er(H2tehy)2(H2O)]2([Cu2Er(H2tehy)2(NO3)]2}(NO3)10·2H2O·4CH3OH, (3), where H2tehy = C19H20N2O4 is a tetrahydroxy Schiff base ligand. Topological analysis showed that the same characteristic motif of coordination accompanied by hydrogen bonds involving the uncoordinated nitrate oxygen atom and ligand’s phenoxy O atoms is responsible for linking trinuclear subunits into a hexanuclear one as well as for bridging the hexanuclear coordination units in 3 into a 1D supramolecular polymer, with the Cu–O distance being 3.19(1) Å, much longer than the limit of a semi-coordination bond (3.07 Å). The Cambridge Structural Database was used to discuss issues of crystallographic criteria (distance and angular preferences) for the assessment of the stabilizing or destabilizing effect of hydrogen bonding on coordination. The presented results show that the symmetrically repeated arrangement of molecules may provide a useful tool for identifying higher order non-covalently bonded supramolecular aggregates. The complexes 1–3 have been characterized by X-ray diffraction, FTIR, and thermal analysis. The magnetic studies indicated the ferromagnetic interaction between CuII and HoIII ions.

Antimicrobial activity of some novel 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives

Background

Infectious diseases, especially those caused by multidrug-resistant bacteria, are becoming a serious problem worldwide because of the lack of effective therapeutic agents. Moreover, most antifungal drugs exhibit low efficacy and high toxicity because of the similarity between fungal and human cells. These issues warrant the search for potential new agents.

Objectives

To synthesize potent 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives, improve the synthetic process, elucidate their structures, and determine their antimicrobial activity.

Methods

2-Iodoaniline was used as an initial reactant in a 3-step process for the synthesis of 2-(2-iodophenylimino)-5-arylidenethiazolidin-4-one derivatives, including an acylation reaction, a cyclization reaction, and aldol condensation reactions. The structures of the obtained derivatives were investigated and elucidated using spectral methods. Antimicrobial activity toward 5 bacterial strains and 2 fungal strains was determined using Kirby–Bauer and agar dilution methods.

Results

We successfully synthesized 12 novel compounds and elucidated their structures. The derivatives had no antifungal activities. By contrast, they showed remarkable antibacterial activities. Some of them with minimum inhibitory concentrations (MICs) ≤8 μg/mL in both Staphylococcus aureus and methicillin-resistant S. aureus.

Conclusions

A simple and flexible way to synthesize new compounds with a thiazolidin-4-one ring was determined. Some of these new compounds have outstanding effects with low MICs for bacteria. Their further investigation as therapeutic agents is warranted.