A large number of higher plants produce economically useful organic compounds such as dyes, oils, resins, waxes, tannins, flavors, gums, and fragrances.
Plants are also capable of synthesizing diverse types of organic molecules collectively called phytochemicals.
These are metabolic intermediates or products essential to growth and also required for the interaction of plants with their environment and produced in response to stress.
Chemicals obtained from plants:
Major classes of phytochemicals: terpenes, phenolics, glycosides, and alkaloids.
Terpenes: constitute a large class of natural products built up from isoprene units.
Phenolics: characterized by the presence of aromatic ring structure bearing one or more hydroxyl groups.
Glucosides: molecules in which a carbohydrate is bound by a glycosidic bond to a non-carbohydrate moiety containing a hydroxyl group.