Synthesis, spectroscopic characterization, antileishmanial, DNA binding, antioxidant, cytotoxicity, antifungal and antibacterial studies of organotin(IV) carboxylate complexes

Abstract

Six new organotin(IV) complexes, [Bu2SnL] (1), [Me2SnL] (2), [Me3SnL] (3), [Bu3SnL] (4), [Ph3SnL] (5) and [(n-Oct2SnL] (6) have been synthesized from the reaction of 4-((5-chloro-2-hydroxyphenyl)ethylideneamino)methyl)cyclohexanecarboxylic acid (HL) with the corresponding diorganotin(IV) dichloride/oxide or triorganotin(IV) chloride.All the synthesized compounds were structurally characterized by elemental analysis, FT-IR, multinuclear NMR (1H and 13C) spectroscopies and powder X-ray diffraction analysis. The results of spectroscopic studies support coordination of oxygen donor site of the ligand with the tin atom of di andtriorgnaotin(IV) moieties. Currently, a vaccine for leishmaniasis remains unavailable, and the existing antimonial-based drugs are accompanied by significant and adverse side effects. The synthesized compounds were screened for antileishmanial activity against promastigotes form of leishmania tropica. Highest activity was shown by compound 2 with an IC50 value of 1.17 ± 0.01 µg/mL, as compared to amphotericin B with IC50 value of 0.71 ± 0.01 µg/mL The synthesized compounds were also subjected to interaction studies with single-stranded DNA (SS-DNA). Among these compounds, Compound 2 demonstrated the most substantial binding affinity, exhibiting a binding constant of 2.7x103 M−1. Furthermore, the compounds also showed excellent antioxidant potential with percentage radical scavenging value in the range of 87–95% and IC50 46.92, 72.10, 46.33 Μg/mL for compounds 1, 5 and 6respectively. The complexes revealed significant toxicity with comparable LD50(6.26 μg/mL), (6.79 μg/mL), (5.67 μg/mL)and (5.80 μg/mL)for complex 2, 3,5 and standard drug respectively. Similarly, the complexes also showed significance antifungal and antibacterial activity.