The history of drugs is intimately linked with plants from the earliest times and even today plant products find extensive use in ethnomedicine, traditional system of medicine as well as in the armamentarium of the modern physician. Plants serve as a reservoir of an enormous variety of novel compounds, which not only act as potential drugs in their unmodified form but also as model compounds for synthetic or semi-synthetic structures, modifications and optimization, as biochemical or pharmacological probes and as a source of inspiration to synthetic organic chemists. World scenario of the use of drugs has been showing signs of a change. There has been a global resurgence of interest in plant-based pharmaceuticals. Today natural products and their derivatives/analogs present over 50% of all the drugs in clinical use.