Comparative HPLC analysis of emodin, aloe emodin and rhein in Rheum emodi of wild and in vitro raised plants

Abstract

The plants are like microbiosynthetic factories having variety of compounds which are their secondary metabolites. These compounds mainly include alkaloids, glycosides, flavonoids, volatile oils, saponins, etc. with tremendous biological activities. The medicinal properties are attributed to the specific bioactive compound or combination of phytochemicals. Rheum species contains anthraquinone derivatives, anthronones and tannins, etc., in which anthraquinone derivatives including emodin, aloe-emodin, rhein, physcion, chrysophanol and their glucosides are the accepted important active components. The methods commonly used for the determination of the anthraquinone compounds in Rheum species are high performance liquid chromatography (HPLC). Aloe-emodin is a natural active compound present in the Rheum species. It has also been found that aloe-emodin has numerous biological properties including antiviral, antimicro­bial and hepatoprotective activities. Aloe-emodin has been reported to exhibit anticancer activity on neuroectodermal tumors, lung squamous cell carcinoma and hepatoma cells. Another compounds found in Rheum species are emodin, rhein, chrysaphanol, physicion etc.