[CMMIM][BF4] ionic liquid catalyzed efficient synthesis of henna based xanthene derivatives and their photophysical, theoretical and molecular docking studies

Abstract

Henna-based xanthene and its derivatives represent a significant class of heterocyclic compounds, exhibiting a wide range of pharmacological and biological activities. In this article, we present a revamped method for the synthesis of henna-based xanthene derivatives by using 4 mol% of [CMMIM][BF₄] ionic liquid in a one pot, metal-free, eco-friendly aqueous ethanol solvent at 80 °C. A series of 32 derivatives were synthesized in 20–50 min, with yields of up to 92 %, and were characterized using various spectroscopic methods. UV–Visible and fluorescence spectroscopy were utilized to investigate the photophysical properties of synthesized henna-based xanthene derivatives. The absorption and emission spectra exhibited peak wavelengths (λ_max) ranging from 395 to 410 nm and 413 to 415 nm, respectively. Theoretical studies revealed a trend consistent with experimental results. Furthermore, molecular docking using AutoDock Vina was performed to evaluate the binding interactions of the synthesized derivatives with Bovine Serum Albumin (BSA) and deoxyribonucleic acid (DNA), demonstrating binding affinities between −8.0 to −11.5 kcal/mol⁻¹ for BSA and −8.5 to −10.9 kcal/mol⁻¹ for DNA.