Phytochemistry and Biological Activity Perspectives of Rheum Species

The genus Rheum is a member of the family Polygonaceae. Rheum species, generally known as Rhubarb growing in high altitude, are important medicinal herbs containing secondary metabolites and grow in India, China, Korea, and Japan. Several chemical constituents from Rheum species are pharmacologically important. Besides being used as herbal medicine and also used in the vegetables and for making natural dyes. More than 250 constituents including anthraquinones (emodin, chrysophanol, physcion, aloe-emodin, and emodin glycosides), anthrones, flavonoids, acylglucosides, pyrones stilbene etc. are the major bioactives of rhubarb that exhibit several biological activities are used folk medicine for the treatment of fever, dysentery, blood coagulation, laxative, anticancer and also used in various skin diseases. This article is an attempt to highlight several of chemical constituents isolated from these species and their medicinal properties. Keywords: Rhubarb, anthraquinones, chemical constituents, biological activities, polygonaceae, emodin.