Chemotaxonomical Classification of Crude drug

This system of classification relies on the chemical similarity of taxon i.e. it is based on the existence of relationship between constituents in various plants . There are certain types of chemical constituents that characterize certain classes of plants . This gives birth to entirely new concept of chemotaxonomy that utilizes chemical facts / characters for understanding the taxonomical status , relationships and the evolution of the plants . For example , tropane alkaloids generally occur among the members of Solanaceae thereby , serving as a chemotaxonmic marker . Similarly plant metabolites can serve as the basis of classification of crude drugs . The berberine alkaloid in Berberis and Argemone ; Rutin in Rutaceae members , ranunculaceous alkaloids among its members etc are examples .

It is the latest system of classification and gives more scope for understanding the relationship between chemical constituents , their biosynthesis and their possible action .