Extraction, Fractionation, and Characterization of Plumbagin from the Roots of Plumbago zeylanica

Abstract

Plumbago zeylanica, a prominent medicinal plant, is renowned for its bioactive constituent, plumbagin, a naphthoquinone with notable pharmacological properties, including anticancer, antimicrobial, and anti-inflammatory effects.The efficient extraction and detailed characterization of plumbagin are essential for its clinical applications. This study aimed to optimize a method for the extraction, fractionation, and characterization of plumbagin from the roots of P. zeylanica. A Soxhlet extraction method was utilized with an appropriate solvent system to obtain a crude extract rich in plumbagin. Column chromatography was employed for the fractionation of the crude extract, and thin-layer chromatography (TLC) was used to identify plumbagin-containing fractions by comparing their Rf values with a standard. The isolated compound was subjected to comprehensive characterization using UV-Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), and mass spectrometry (MS). The optimized extraction and fractionation method yielded 7.2% (w/w) crude extract and 2.81% (w/w) plumbagin. The Rf value of the extract was determined to be 0.86. UV-Vis spectroscopy confirmed the presence of plumbagin by exhibiting characteristic absorption maxima at 265 nm. FTIR analysis supported this identification by revealing peaks corresponding to the naphthoquinone structure. ¹H NMR spectroscopy provided further structural insights, confirming the presence of specific protons and carbons within the compound. This study establishes an efficient protocol for extracting and characterizing plumbagin from P. zeylanica roots, facilitating future research into its therapeutic potential and enhancing its applicability in the pharmaceutical and medicinal fields.