From synthesis to bioactivity: Characterization, crystallography, antimalarial and antimicrobial activities of hydrazone-derived organotin(IV) complexes

In recent times, there has been a growing exploration of transition metal complexes as potential solutions for significant health challenges, including tuberculosis, microbes infection, and inflammation. Therefore, in our ongoing effort to identify biologically effective agents, Co(II), Ni(II), Cu(II), and Zn(II) metal complexes of H2L1–H2L2 hydrazone ligands were synthesized. The structural features of synthesized compounds were recognized by employing several techniques such as FT‐IR, 1H NMR, 13C NMR, powder x‐ray diffraction (XRD), UV‐Vis, ESR, TG‐DTA, mass spectrometry, and molar conductance measurements. The bonding of ligands via Ophenolic, Oenolic, and Nazomethine donor atoms and the attachment of the three water molecules with metal ion to form the octahedral structure of complexes were corroborated by different spectroscopic techniques. The anti‐tuberculosis, antimicrobial, and anti‐inflammatory activities of the synthesized compounds were assessed using the microplate alamar blue assay, serial dilution, and bovine serum albumin (BSA) methods, respectively, and highlighted the more potency of the complexes than ligands. The synthesized Cu(II) (9) and Zn(II) (10) metal complexes exhibited excellent ability to inhibit the growth of H37Rv strain of Mycobacterium tuberculosis in comparison to standard drug streptomycin. The Cu(II) (6 and 9) and Zn(II) (10) complexes showed superb ability as antimicrobial agents, whereas Cu(II) (5) and Zn(II) (6) complexes exhibited significant anti‐inflammatory ability. The in vitro findings on the antituberculosis activity were reinforced by a significant molecular docking study, which has become a crucial component of computational research utilizing the enzyme Mtb Pks13 thioesterase domain of M. tuberculosis. Additionally, in this research work, the absorption–distribution–metabolism–excretion–toxicity (ADMET) study sparked the compounds' drug‐like behavior.

A Robust In Vitro Anti‐tuberculosis, Antimicrobial, and Anti‐inflammatory Activities Based on Azomethine Chelates Incorporating Co(II), Ni (II), Cu(II), and Zn(II) Ions: Synthesis, Characterization, and Investigation of the Aspects of Docking Interaction

Rani,

Devi,

Kumar

et al. 2024

Exploring Antiplasmodial, Antimicrobial, Antioxidant, and Docking Profile: Conjugating Organotin Moiety With Hydrazones for Enhanced Efficacy

Boora,

Devi,

Kumar

2024

In the 21st century, pathogenic deformities contribute significantly to global morbidity and mortality. Our research investigates the antimalarial, antimicrobial, and antioxidant activities of newly synthesized hydrazones and their organotin (IV) complexes, derived from 2‐benzoyl‐1H‐indene‐1,3(2H)‐dione and 2‐phenoxypropanehydrazide/2‐(2,4‐dichlorophenoxy)propanehydrazide. Structural confirmation was achieved through multinuclear nuclear magnetic resonance (NMR), UV–Vis, IR, HRMS, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM)‐energy‐dispersive X‐ray analysis (EDAX), revealing tridentate coordination of ligands to the tin metal via imine nitrogen and two enolic oxygens, forming a pentacoordinated geometry. The SEM analysis revealed that hydrazone ligand (1) exhibits a rectangular bar‐like microstructure, whereas its complex (5) shows a rugged surface with distinct territorial patches. Compounds (5) [Bu2SnL1] and (6) [Ph2SnL1] stood out with significant bioactivity, with antimalarial IC50 values ranging from 0.54 ± 0.07 to 0.67 ± 0.06 μM and antioxidant IC50 values from 4.39 ± 0.02 to 4.67 ± 0.01 μM. Additionally, compounds (6) [Ph2SnL1] and (10) [Ph2SnL4] exhibited the highest antimicrobial activity, with MIC values ranging from 0.0045 to 0.0042 μmol/mL, respectively, comparable to standard drugs. Complementing the experimental data, in silico molecular docking studies were performed on the most effective ligand (1) [H2L1] and its phenyl complex (6) [Ph2SnL1] with Plasmodium falciparum lactate dehydrogenase, revealing binding energies of −6.0 and −6.9 kcal/mol, respectively, and corroborating the experimental findings. Further, comprehensive absorption, distribution, metabolism, excretion, and toxicity (ADMET) evaluations were performed on each compound to gauge their suitability as drug candidates and potential for toxicity.

Biological Synergy of Diorganotin (IV) Metal With Schiff Bases: Synthesis, Characterization, Antituberculosis, Antimicrobial, and Anti‐Inflammatory Evaluation

Taxak,

Devi,

Kumar

et al. 2024

In the search for new therapeutic agents, a variety of diorganotin (IV) complexes were synthesized from Schiff base ligands (H2L1–H2L2) derived from 2‐amino‐4,6‐dichloro‐5‐methylphenol and 5‐nitrosalicylaldehyde/5‐chlorosalicylaldehyde. Structural characterization was performed using various analytical and physical techniques. Spectroscopic data confirmed that the ligands coordinate to the diorganotin (IV) ion via O‐ and N‐donor sites in an iminol configuration, indicating a pentacoordinated stereochemistry. TGA studies showed stability up to 120°C, and low conductance suggested nonelectrolytic nature. Bioactivity screening included the alamar blue assay for antituberculosis activity, serial dilutions for antimicrobial testing, and the bovine serum albumin technique for anti‐inflammatory evaluation. Notably, Complex 6 [Ph2SnL1] displayed the highest efficacy against tuberculosis (MIC: 0.0102 ± 0.0017 μmol/mL) and inflammation (IC50:7.9437 ± 0.02 μM) dysfunctions, which is comparable to standard drugs. Moreover, the metal complexes, particularly Complexes 6 and 10, exhibited the most promising antimicrobial activity with 0.0051–0.0052 μmol/mL MIC values. The efficacy pattern was Ph2SnL1–2 > Bu2SnL1–2 > Et2SnL1–2 > Me2SnL1–2. Evaluation of the ADMET profile elucidated the low toxicity levels and drug likeness properties of these compounds, highlighting their potential as promising therapeutic agents.