Chemical Composition and Antioxidant Activity of Rhododendron lepidotum Wall. ex D. Don, Essential Oil from Nepal

Rhododendrons are of the genus Rhododendron that belonging to the family Ericaceae. It is represented by about 1025 species in the world, mostly concentrated in the Himalayan region of Nepal, and the temperate regions of Northern hemisphere especially in Sino-Himalayas (Eastern Himalayas and Western China). Besides this main centre, the Rhododendrons have further proliferated towards southern and northeastern China, Japan, Myanmar, Thailand, Malaysia, Indonesia, Philippines and New Guinea. A few species are also reported from Afghanistan, Australia Pakistan, southern parts of Europe and northern parts of America [1]. In Nepal, this genus comprises 32 species most of these are distributed at the altitude ranging from 1500-5000m.This genus has long been used as folk medicine in Nepal and other countries of the world. A few members of this genus such as R. ponticum and R. lustem contained grayanine type tetracyclic diterpenes which are known to be toxic to common livestock such as cattle. But a large members of this genus contained bioactive chemical constituents such as essential oils, ursolic acid, oleanolic acids, phenol, coumarins, flavonoids, etc these are important for human being [2].