Isolation and high-performance thin layer chromatographic estimation of Lupeol from Oxystelma esculentum
Background: Oxystelma esculentum R. Br. (Family: Asclepiadaceae) is a perennial twiner growing in water-logged areas of the Indian sub-continent. It is used traditionally as a diuretic, laxative and an anti-ulcer agent. However, there is no method available for isolation and estimation of a marker compound from this plant. The present work deals with the isolation and structure elucidation of Lupeol from O. esculentum and high-performance thin layer chromatographic (HPTLC) method development for its estimation. Materials and Methods: The petroleum ether extract of the entire plant of O. esculentum was subjected to further fractionation followed by pilot thin layer chromatographic (TLC) experiments and column chromatography. This yielded a pure, white, crystalline solid which resolved at Rf 0.65 upon TLC of chloroform fraction of the petroleum ether extract using the mobile phase toluene: methanol (9:1). Results: This compound was subjected to ultraviolet (UV), infrared (IR), gas chromatography-mass spectroscopy (GC-MS) and 1H-nuclear magnetic resonance (1H-NMR) spectral analysis and its structure elucidation revealed it to be Lupeol. A novel HPTLC method for the estimation of Lupeol from O. esculentum was developed, in which it was found to be 0.829 ± 0.09% w/w. Conclusions: The method developed was found to be easy, simple, precise, efficient, accurate, reproducible, specific and sensitive, and could serve as a suitable tool for routine analysis and phytochemical authentication of O. esculentum.