Isolation And Characterization of Quercetin-3-O-Glucoside from Terminalia Chebula Retz Seeds

Objective: The investigation was undertaken to isolate and characterize the bioactive flavonoid quercetin-3-glucoside from the seeds of Terminalia chebula Retz., an important medicinal plant widely recognized in traditional systems of medicine. Methods: Terminalia chebula Retz seed extract were prepared by Soxhlet extraction with ethanol. The extracts were subjected to preliminary phytochemical screening and structural elucidation The ethanol extract, identified as the richest in flavonoids and possessing suitable polarity for broad phytoconstituent recovery, was fractionated through column chromatography to facilitate the systematic isolation of bioactive secondary metabolites. The obtained fractions were monitored by thin layer chromatography (TLC) using silica gel G as the stationary phase. Several solvent systems were tested, of which methanol: water (1:9) gave the best resolution. A single prominent fluorescent spot with an Rf value of 0.8 was observed under UV light (365 nm), indicating the presence of a distinct polar phytoconstituent. Fractions with similar Rf values were pooled, recrystallized in methanol, and purified crystals were obtained. Structural elucidation of the isolated compound was carried out using UV–Visible spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, Proton Nuclear Magnetic Resonance (¹H NMR), Carbon-13 Nuclear Magnetic Resonance (¹³C NMR), and Mass spectroscopy. Results: Ethanol extract revealed a significant number of flavonoids compared with other solvent extracts. TLC and column chromatography confirmed the presence of a single major phytoconstituent. Spectral data (UV–Vis, FT-IR, ¹H NMR, ¹³C NMR, and MS) confirmed that the isolated compound was quercetin-3-glucoside. Conclusion: The study successfully demonstrated the extraction, isolation, and structural characterization of quercetin-3-glucoside from Terminalia chebula seeds, thereby providing a scientific basis for its phytochemical richness and potential applications in natural product research.