Heterocycle-derived organosilatranes as naked eye sensors for Sn2+ ions and their potential inhibiting activity against HIV-1 protease via a computational approach

Abstract

Nitrogen-based heterocycles are frequently present in active pharmaceutical products. Inspired by this, we design heterocycle-appended organosilatranes having an azomethine linkage using a simple synthetic approach. All the synthesized organosilatranes were well characterized by elemental analysis; FTIR, NMR (¹H and ¹³C) and mass spectrometry. The chemosensor shows high selectivity towards Sn²⁺ metal ions and the transparent solution of the ligand turned to yellow colour in the presence of Sn²⁺ ions. The ligand binds with metal ions with a high binding affinity (K_a = 3.5 × 10⁶ M⁻¹). Furthermore, by using fluorometric spectroscopy, the limit of detection was calculated to be 4.5 × 10⁻⁸ M. In addition, to find the binding mode of the ligand and metal, the complex was synthesized and characterized by ¹H NMR spectroscopy and DFT calculations were also performed. Also, the bioavailability of the compounds was confirmed by pharmacological investigations using Molinspiration and PreADMET online servers and the results show that all the synthetic silatranes obey Lipinski's rule and possess acceptable ADMET properties. Moreover, the molecular docking studies provide valuable information regarding the interaction of compound 4a with the HIV-1 protease protein with a binding energy of −7.00 kcal mol⁻¹.