ABSTRACT
Chemical constituents of the herbs form an integral part of the research for herbal drug development. The chemical identification of morphine was carried in 1923, by Robinson and Gulland. So far, there are more than 20,000 alkaloids identified and a number of them have been placed an important role in clinical practice. Nonterpenoid bitters are classified according to their chemical structure: henolic bitters e.g., humulone and lupulone; hromone bitters e.g., khellin and visnagin; coumarin bitters e.g., xanthotoxin, imperatorin and bergapten; coumarone bitters e.g., rotenone; anhydride bitters e.g., cantharidin. Anthraquinones are phytochemicals based on anthracene. At each apex of the central ring is a carbonyl group, which is the quinone part. The gum and mucilage are common constituents of plants, and have traditionally been distinguished by their physical properties. However, there is no clear chemical distinction between the two, as they are often found together.
