Organotin(IV) complexes of carboxylate derivative as potential chemotherapeutic agents against Leishmania

The aim of the present research is to search for new antileishmanial drugs as potential chemotherapeutic agents. We have some newly synthesized organotin(IV) based peptide derivatives of carboxylate ligand as potential chemotherapeutic agents against Leishmania. Antileishmanial activity was carried out against Leishmania tropica KWH23 strain, and the compounds showed significant activity except MS20, main ligand with no tin. Biocompatibility assays showed that the tested compounds have LD50 values ranging from 60.296 to 224.759 mu g/mL with the exception of MS20Me3 (596.91 mu g/mL) and MS(20)Oct(2) (405.72 mu g/mL). They were found highly biocompatible. From the in-silico studies, all the synthetic derivatives except MS20Me3 (1,10-Ph) and MS20 were bound to leishmanolysin (GP63) receptor. This binding probably resulted in a receptor mediated inlet of these synthetic derivatives inside the Leishmania cells, where they were further bound to the DNA (confirmed by DNA interaction study). The interaction caused a redox reaction between the DNA and the compounds, which lead to the degradation of DNA and caused apoptotic death of L. tropica. The results suggested that the organotin(IV) derivatives have good potential as chemotherapeutic agents and can be a better replacement for the currently available drugs. (C) 2014 Elsevier B.V. All rights reserved.