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

Abstract

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 Ph₂SnL^1–2 > Bu₂SnL^1–2 > Et₂SnL^1–2 > Me₂SnL^1–2. Evaluation of the ADMET profile elucidated the low toxicity levels and drug likeness properties of these compounds, highlighting their potential as promising therapeutic agents.