Alkaloids are pharmacologically active containing two or more fused organic compound including heteroatom in it. The quinoline alkaloids from higher plants are best classified according to their biogenetic derivation from either anthranilic acid or tryptophan Cinchona which belongs to family Rubiaceae, got its importance from the centuries because of its antimalarial activity. Alkaloids present in this herb, Quinine, Chichonine, Quinidine and Cinchonidine are the main alkaloids of this class. Another major important plant of this class is camptotheca which belongs to family nyssceae having the antitumor property. Alkaloids containing the imidazole nucleus which is the smallest groups of alkaloids in terms of number of known compounds. This class of alkaloids is synthesized by precursors derived directly from the amino-acid histidine. This class of alkaloids contain Pilocarpine, Alchornine, and White sapote. Pilocarpine belongs to family Rutaceae which shows muscarinic receptor agonistic property.Alchornine is from family Euphorbiaceae which is used to treat bacterial infections .White sapote belongs to family Rutaceae which shows anti-inflammatory sedative and mildly narcotic action.
