Extraction, isolation and chemical structure elucidation of Digoxin cardiac glycoside from Leonurus cardiaca L. extract

The Leonurus cardiaca L. is a perennial herbaceous medicinal plant. This species belongs to Lamiaceae family and commonly known as “lion's tail” in Persian. L. cardiaca is widely used in Iranian traditional medicine and others as sedative, hypnotic, diuretic and blood pressure reducer agent. This species is using in remedy of heart diseases. Many important phytochemical compounds such as alkaloid, iridoid, saponins, flavonoids, carotenoids and diterpenoids have been previously extracted and identified from L. cardiaca. Regarding the importance of plant and also presence in the Country, this study was defined to investigate the phytochemical constituents of L. cardiaca extract in order to evaluate and identify of natural compounds. Hence the aerial parts of plant were collected from natural habitat in hillsides of Damavand Mountain (Mazandaran Province) in flowering growth stage. The shade dried materials were powdered and then were extracted using maceration method. The extract was defatted using Hexane solvent in next step. Chromatography column was used for fractionation of extract and 32 different fractions were isolated as the result. A natural compound's crystal was appeared in fraction 8+9+10 and so its chemical structure was evaluated using spectro-photometric methods (1H-NMR,13C-NMR, IR and DEPT Techniques). Based on the obtained spectra, natural compound of Digoxin (a well-known cardiac glycoside from other plant species) was extracted, purified and identified from L. cardiaca extract for the first time in the world.