Isolation and high-performance thin layer chromatographic estimation of Lupeol from Oxystelma esculentum

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.

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).

This compound was subjected to ultraviolet (UV), infrared (IR), gas chromatography-mass spectroscopy (GC-MS) and (1) H-nuclear magnetic resonance ((1)H-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.

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.