Parietin
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| Surname | Parietin | ||||||||||||||||||
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| Molecular formula | C 16 H 12 O 5 | ||||||||||||||||||
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| Molar mass | 284.26 g mol −1 | ||||||||||||||||||
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||||||||||||
Parietin is a dye from the group of the anthraquinones .
Occurrence
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The natural substance occurs in various lichens, including lichen of the genus Caloplaca and common yellow lichen . It is there extracellularly in the thallus . The biosynthesis of this substance is carried out by the non-photosynthetic partner in the lichen, i.e. the fungus.
description
The yellow substance, which is soluble in acetone, is a derivative of anthraquinone . It reacts purple-red with potassium hydroxide or ammonia water. Violet insoluble salts form with barite water or lime water .
use
Basic properties of this secondary plant substance were already known in the 18th century and were described by Rémi Willemet . According to his observation, residents of Öland obtained a yellow dye for coloring wool from a lichen of the genus Parmelia with the help of alum , and the lichen itself was eaten by goats. According to Hermann Hoffmann , it was also boiled in milk as a remedy for jaundice .
function
The concentration of the dye in the lichen is higher when it is exposed to more light; H. higher on a sunny rock than on a shady tree, and higher in summer than in winter.
The biological function of the substance is seen in a protective effect against UV-induced cell damage and in a reduction in photoinhibition . Their metabolism has not yet been conclusively researched. The model is the biosynthesis of orsellic acid , i.e. by ring closure of polyketides .
literature
- Knut A. Solhaug and Yngvar Gauslaa: Parietin, a photoprotective secondary product of the lichen Xanthoria parietina . In: Oecologia Vol. 108, No. 3, 1996, pp. 412-418, doi: 10.1007 / BF00333715
Individual evidence
- ↑ a b Physcion data sheet ≥98.0% from Sigma-Aldrich , accessed on February 8, 2012 ( PDF ).
- ↑ R. Hegnauer: Chemotaxonomy of Plants: Volume 1: Thallophyten, Bryophyten, Pteridophyten und Gymnospermen . tape 1 . Birkhäuser, 1962, ISBN 978-3-7643-0164-4 , p. 154 ( limited preview in Google Book search).
- ^ Wilhelm Zopf : The lichen substances in chemical, botanical, pharmacological and technical relationship. 1907, p. 342.
- ^ Robert D. Thomson: About the Parietin. In: Polytechnisches Journal . 93, 1844, pp. 372-380.
- ↑ Knut Asbjørn Solhaug, Yngvar Gauslaa: Secondary Lichen Compounds as Protection against Excess Solar Radiation and Herbivores . In: Progress in Botany . tape 73 . Springer, 2012, ISBN 978-3-642-22745-5 , pp. 283 ff . ( limited preview in Google Book search).
- ↑ Teresa Pereyra, Maria del Carmen Molina, Maria Segovia, J. L Mateos, C. Vicente: Study of parietin production by immobilized cells of Xanthoria parietina in calcium-alginate matrix . In: RH Wijffels (Ed.): Immobilized cells: basics and applications: proceedings of an international symposium organized under auspices of the Working Party on Applied Biocatalysis of the European Federation of Biotechnology, Noordwijkerhout, The Netherlands, November 26-29, 1995 . Elsevier, 1996, ISBN 978-0-444-81984-0 , pp. 390 ff . ( limited preview in Google Book search).