Chemotaxonomy

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Chemotaxonomy is a part of taxonomy in which organisms (mainly plants) are classified based on differences and similarities in their biochemical composition, especially phytochemicals . Biochemical characteristics are used in a manner analogous to morphological characteristics for the analysis of the relationships. Today, in addition to the classic biochemical methodology and methods such as thin-layer chromatography , the analysis of the entire chemical metabolism, the metabolome, often attached here under the name metabolomics. The term chemotype, formed in analogy to the genotype, is used less often. Classical phylogenomics , in which the relationship is investigated by comparing homologous DNA sequences, is a clearly separate branch of research.

While some authors want to restrict the term chemotaxonomy to the narrower field of the classification of species, this usually also includes the analysis of relationships, i.e. the field of biological systematics . The terms chomotaxonomy and chemosystematics are usually used synonymously.

Because some natural substances occur alone or mainly in certain species, genera or families, this can provide a basis for taxonomic classifications in addition to the morphology. Examples are the occurrence of floridzine in apples , tariric acid in the Picramniaceae , colchicine in the timeless family , lycorine in the daffodil family , and primin in primula . Some are characteristic of orders and are used to structure them, such as the betalaine as flower coloring substances in the Caryophyllales and the sulphurous mustard oil glycosides (or glucosinolates) in the Brassicales . The most important classes of compounds used for chemotaxonomy are polyphenols , especially flavonoids , glycosides and mustard oil glycosides , including cyanogenic glycosides and alkaloids .

Due to the development of ever better analysis methods, compounds that were previously only known from certain plants are now also detected in smaller concentrations in other plants. One example is nicotine , which occurs in very high concentrations (4%) in plants of the Nicotiana genus , known among other things from the common tobacco plant Nicotiana tabacum . Nicotine seems to be found in other plants in the plant kingdom, but in much lower concentrations than in Nicotiana . As a result, this was not previously detectable.

An important work in chemotaxonomy is the thirteen-part series Chemotaxonomy of Plants by Robert Hegnauer . In it, he describes the occurrence, functioning and biosynthesis of secondary plant substances for each family . Other, more succinct works are Chemical Plant Taxonomy by Tony Swain and Systematics of the Plant Kingdom : With special consideration of chemical characteristics and plant drugs by Dietrich Frohne and Uwe Jensen. Biochemical Systematics and Ecology is a journal focused on chemotaxonomy.

Web links

literature

  • Robert Hegnauer: Chemotaxonomy of plants: An overview of the distribution and the systematic importance of plant substances . Birkhäuser, Basel 1990, ISBN 978-3-7643-2299-1 .

Individual evidence

  1. ↑ Coleen A. Mannheimer (1999): An overview of chemotaxonomy, and its role in creating a phylogenetic classification system. Agricola 1998/1999 87-90
  2. ↑ W. Seitz (1979): Chemosystematics today, illustrated by some examples from the angiosperm families Ranunculaceae, Onagraceae, Valerianaceae and the Lichenes group. Reports of the German Botanical Society 92: 519-534. doi: 10.1111 / j.1438-8677.1979.tb03297.x
  3. ↑ Tom Reynolds (2007): The evolution of chemosystematics. Phytochemistry 68 (22-24): 2887-2895. doi: 10.1016 / j.phytochem.2007.06.027
  4. ^ Anne E. Desjardins (2008): Natural Product Chemistry Meets Genetics: When Is a Genotype a Chemotype? Journal of Agricultural and Food Chemistry 56 (17): 7587-7592. doi: 10.1021 / jf801239j
  5. ↑ Robert Hegnauer: Chemotaxonomy of plants. Volume 7: Supplements to Volume 1 and Volume 2. Birkhäuser, Basel / Boston / Stuttgart, (new edition: Springer Verlag) 1986. ISBN 978-3-0348-9314-5 . therein chapter A2, notes on terminology.
  6. ↑ a b Tod F. Stuessy: Plant Taxonomy: The Systematic Evaluation of Comparative Data. Columbia University Press, 2009. ISBN 978-0-231-51864-2 . therein chap. 19: Phytochemistry.
  7. ^ OP Sharma: Plant Taxonomy (Second Edition). Tata McGraw-Hill Education, New York, 2009. ISBN 978-0-07-014159-9 . therein chap. 11: Chemotaxonomy.
  8. ↑ Ram Singh (2016): Chemotaxonomy: A Tool for Plant Classification. Journal of Medicinal Plants Studies 4 (2): 90-93.
  9. ↑ Horst Fribolin: One and two-dimensional NMR spectroscopy, 2nd edition, VCH Weinheim 1992, ISBN 3-527-28507-5 .
  10. ^ Manfred Hesse, Herbert Meier, Bernd Zeeh: Spectroscopic methods in organic chemistry, 3rd edition. Georg Thieme Verlag, Stuttgart New York 1987, ISBN 3-13-576103-7 .
  11. ↑ Peter Nuhn : Naturstoffchemie. Microbial, vegetable and animal natural substances . 2nd edition, S. Hirzel Wissenschaftliche Verlagsgesellschaft, Stuttgart 1990, p. 564, ISBN 3-7776-0473-9 .