Active Principles

Abstract

The term “active principle” refers to the intrinsic chemical substance which induces pharmacological activity. Plant organisms, though different in form, organization and environmental adaptability, use a rather limited number of substances for their biochemical processes (carbohydrates, lipids, proteins, nucleic acids, co-enzymes and vitamins). Plants are often capable of synthesizing a large variety of organic compounds, the significance of which is clear only in some cases - essential oils of the Coniferae are useful in that their resin solvents function as a protective for wounds. The biosynthesis of these compounds comes about through metabolic processes which use intermediary products of the primary metabolism. Through this process certain biochemicals accumulate in plant cells. The metabolic conversions that take place vary from one plant species to another, and depend on environmental and genetic factors. The active principles are mainly formed during the period of plant growth when metabolic transformation is at its greatest. The active principle may be represented by primary cellular constituents (proteins, lipids, polysaccharides), by intermediary metabolites (organic acids) and by secondary cellular constituents (alkaloids, glycosides, flavonoids, saponins, tannins, essences, etc.). It is the latter which contains the most interesting active principles from a pharmacological point of view.