Secondary metabolites

from Wikipedia, the free encyclopedia

Secondary metabolites (secondary metabolites or secondary metabolites ) are chemical substances that are produced by plants , bacteria , fungi or animals (e.g. insects, sponges, soft corals), but which do not appear to be necessary for their growth and survival (in contrast to the primary metabolites such as amino acids or sugars ). In addition, the word secondary metabolites is also used for phytochemicals .

properties

Secondary metabolites are mostly excreted as metabolic end products by excretion .

While some secondary metabolites due to their diverse effects on humans u. a. are of extraordinary interest in medicine, the use of some secondary metabolites for the producer (bacterium, fungus) has not been clearly established. They may serve as a chemical defense against competing organisms (e.g. substances with an antibiotic effect) or as signal substances to control biological functions. It is also possible that the secondary metabolites are just a remnant of the respective evolutionary process .

In biotechnology , the microbial production of secondary metabolites is used in a targeted manner, e.g. B. by selecting suitable bacterial or fungal strains (high-performance strains, high-performance mutants), optimized fermentation conditions or the addition of chemical substances during the growth phase (precursor-directed biosynthesis). Secondary metabolites are often biological agents , such as. B. antibiotics , toxins , insecticides or messenger substances and have therefore in some cases achieved great economic importance. One of the best-known examples of the benefits of secondary metabolites is the growth-inhibiting effect of the mold Penicillium notatum on bacteria, discovered by Alexander Fleming in 1928 , which forms the basis of antibiotic treatment .

literature

  • H. Schulz, H. Krüger, N. Herchert, ERJ Keller: Occurrence of volatile secondary metabolites in selected Allium wild types . In: Journal of Applied Botany . tape 74 , no. 3-4 . Blackwell, 2000, ISSN  0949-5460 , pp. 119-121 .
  • Melanie Kettering, Daniela Weber, Olov Sterner, Timm Anke: Secondary metabolites from mushrooms - functions and applications . In: BioSpectrum . tape 10 , no. 2 . Spectrum, 2004, ISSN  0947-0867 , p. 147-149 ( biospektrum.de [PDF]).
  • Diana Wolff: Allenes, dihydronaphthalenone derivatives and other secondary metabolites from fungi in marine habitats and contributions to their biosynthesis . Georg-August-University, Göttingen 2004 ( gwdg.de [PDF; 1.9 MB ] dissertation).
  • Reinhard Keller, Klaus Senkpiel, Werner Butte: Molds and their secondary metabolites ( MVOC ) in air samples from unpolluted apartments . In: Hazardous substances, keeping the air clean . tape 67 , no. 3 . Springer-VDI-Verlag, 2007, ISSN  0949-8036 , p. 77-84 .