Structural investigations, anti-leishmanial, antibacterial and docking studies of new pentavalent antimony carboxylates

In order to investigate the new drug candidates for healthy and risk free treatment of parasitic diseases like leishmaniasis, a series of new bioactive pentavalent antimonials (LS-1 to LS-8) of the type [SbR3(OOCR′)2] (R = –C6H5, –(C6H4)CH3 and R′ = –(C6H4)NO2, –(C6H4)Br, CH(C6H5)2, CH2CH(C3H7)NHSO2C6H5) were synthesized. All the antimonials have been characterized using melting points, elemental analysis, and multinuclear (1H and 13C) NMR spectroscopy. In addition two compounds (LS-3 and LS-5) were also studied by X-ray crystallography and showed trigonal–bipyramidal geometry around antimony. The leishmanicidal activity was assessed against the Leishmania tropica promastigote parasite. It was observed that IC50 of the antimonials was many fold superior as compared with the standard antimonial drug used. Antibacterial assay along with docking study proved that the synthesized compounds are highly effective against various human pathogens.