|This article does not cite any references or sources. (December 2009)|
Chemotaxonomy (from chemistry and taxonomy), also called chemosystematics, is the attempt to classify and identify organisms (originally plants), according to demonstrable differences and similarities in their biochemical compositions. The compounds studied in most of the cases are mostly proteins, amino acids and peptides. Examples of chemotaxonomic markers are phospholipid-derived fatty acids and enzymes.
E.G. Family Rutaceae can be distinguished by the presence of oil glands; Families Aschepiadaceae and Apocyanaceae can be differentiated based on the presence of latex.
Chemosystematics can be viewed as a hybrid science that complements available morphological data to improve plant systematics.
John Griffith Vaughan was one of the pioneers of chemotaxonomy. The use of biochemistry in taxonomic studies. Living organisms produce many types of natural products in varying amounts, and quite often the biosynthetic pathways responsible for these compounds also differ from one taxonomic group to another. The distribution of these compounds and their biosynthetic pathways correspond well with existing taxonomic arrangements based on more traditional criteria such as morphology. In some cases, chemical data have contradicted existing hypotheses, which necessitates a reexamination of the problem or, more positively, chemical data have provided decisive information in situations where other forms of data are insufficiently discriminatory. See Animal systematics
Modern chemotaxonomists often divide natural products into two major classes: (1) micromolecules, that is, those compounds with a molecular weight of 1000 or less, such as alkaloids, terpenoids, amino acids, fatty acids, flavonoid pigments and other phenolic compounds, mustard oils, and simple carbohydrates; and (2) macromolecules, that is, those compounds (often polymers) with a molecular weight over 1000, including complex polysaccharides, proteins, and the basis of life itself, deoxyribonucleic acid (DNA).
A crude extract of a plant can be separated into its individual components, especially in the case of micromolecules, by using one or more techniques of chromatography, including paper, thin-layer, gas, or high-pressure liquid chromatography. The resulting chromatogram provides a visual display or “fingerprint” characteristic of a plant species for the particular class of compounds under study.
§ The biochemical characters (e.g; amino acid sequences in the protein of an organism or ascorbic acid composition in birds) in taxonomic identification was first introduced by CANDOLLE in 1913. § Enzyme structure of a living organisms also help in identifying new species.
|Look up chemotaxonomy in Wiktionary, the free dictionary.|
|This biochemistry article is a stub. You can help Wikipedia by expanding it.|