Organotin(IV) derivatives of 4-chloro-2-methylphenoxyacetic acid: synthesis, spectral characterization, X-ray structures, anticancer, enzyme inhibition, antileishmanial, antimicrobial and antioxidant activities.

Four organotin(IV) carboxylate complexes; (CH)SnL (), CHSnL (), (CH)SnL () and (CH)SnL () are synthesized by the condensation reaction of organotin(IV) chlorides with sodium-4-chloro-2-methylphenoxyacetate (). The FT-IR spectra suggested bridging/chelating bidentate coordination of the ligand to the tin atom. Single-crystal XRD analysis authenticated the FT-IR findings for and . The NMR study has shown no significant differences in the signals of the free and coordinated ligand except for absence of a proton and up-filed/down-field shift of the C signal of the carboxyl group in the spectra. Complexes - have shown better enzyme inhibition, antioxidant, antimicrobial, and anticancer activities compared to the free ligand acid. Complex was the most active inhibitor of AChE, BChE, α-glucosidase and α-amylase with IC values of 43.76, 102.39, 232.71 and 91.84 µg/mL, respectively. Additionally, with IC values of 7.52 and 8.77 µg/mL in the DPPH and ABTS assays, respectively was better antioxidant than the standard. Complex was the most efficient inhibitor of MAO-B and COX-2 enzymes with IC values of 106.99 and 12.98 µg/mL, respectively, while (IC = 38.97 µg/mL) has shown the highest 5-LOX inhibition potential. Complexes - with IC values in the range 237.51-168.35 µg/mL have shown better antileishmanial activity than (IC = 277.57 µg/mL). The compounds showed good to potent antiproliferative activity in malignant glioma U87 cells with IC values in the range 12.54 ± 0.05 to 37.65 ± 0.04 µg/mL. Antimicrobial activities have shown promising results for the compounds compared to the standards in some cases.