Lichen product

Last updated

Lichen products, also known as lichen substances, are organic compounds produced by a lichen. Specifically, they are secondary metabolites. Lichen products are represented in several different chemical classes, including terpenoids, orcinol derivatives, chromones, xanthones, depsides, and depsidones. Over 800 lichen products of known chemical structure have been reported in the scientific literature, and most of these compounds are exclusively found in lichens. [1] Examples of lichen products include usnic acid (a dibenzofuran), atranorin (a depside), lichexanthone (a xanthone), salazinic acid (a depsidone), and isolichenan, an α-glucan. Many lichen products have biological activity, and research into these effects is ongoing. [2]

Contents

Biosynthesis

Most lichen products are biochemically synthesized via the acetyl-polymalonyl pathway (also known as polyketide pathway), while only a few originate from the mevalonate and shikimate biosynthetic pathways. [3]

Occurrence

Lichen products accumulate on the outer walls of the fungal hyphae, and are quite stable. Crystal deposits can be visualised using scanning electron microscopy. [4] For this reason, even very old herbarium specimens can be analysed. [5] The amount of lichen products in lichen (as a percentage of dry weight) is typically between 0.1%–10%, although in some instances it may be as high as 30%. [6] They are usually found in the medulla, or less commonly, the cortex. [7]

In 1907, Wilhelm Zopf identified and classified about 150 lichen products. Seventy years later, this number had risen to 300, and by 1995, 850 lichen products were known; [8] as of 2021, more than 1000 have been identified. [9] Analytical methods were developed in the 1970s using thin-layer chromatography for the routine identification of lichen products. [10] [11] More recently, published techniques demonstrate ways to more efficiently harvest secondary metabolites from lichen samples. [12]

Chemical isolateLichen sourceResearched activity and uses
Atranorin Cetraria islandica Analgesic, anti-inflammatory, antimicrobial [13] [14]
Constipatic acid Xanthoparmelia
Lichexanthone Hypotrachyna osseoalba
Portentol Roccella portentosaAnticancer [15]
Salazinic acid Parmotrema, Bulbothrix Antibacterial [16] [17]
Usnic acid Usnea Antibacterial, [18] adrenergic activity [19]

Use in taxonomy

Lichen products play a crucial role in differentiating lichenised fungi, particularly in groups where morphological characteristics are less distinct. This approach is notably applied in the genus Lepraria , which lacks sexual reproduction and ascomata (fruiting bodies), typically key features for species identification. [20] Similarly, in genera with more complex structures like the crustose genus Ochrolechia , [21] and the fruticose Cladonia , [22] [23] the presence, absence, or substitution of specific lichen products is frequently used to distinguish species, especially when these variations align with differences in geographical distribution. [24]

Related Research Articles

Orsellinic acid, more specifically o-orsellinic acid, is a phenolic acid. It is of importance in the biochemistry of lichens, from which it can be extracted. It is a common subunit of depsides.

<span class="mw-page-title-main">Depside</span> Class of chemical compounds

A depside is a type of polyphenolic compound composed of two or more monocyclic aromatic units linked by an ester group. Depsides are most often found in lichens, but have also been isolated from higher plants, including species of the Ericaceae, Lamiaceae, Papaveraceae and Myrtaceae.

<i>Cetrelia</i> Genus of lichens in the family Parmeliaceae

Cetrelia is a genus of leafy lichens in the large family Parmeliaceae. They are commonly known as sea-storm lichens, alluding to the wavy appearance of their lobes. The name of the genus, circumscribed in 1968 by the husband and wife lichenologists William and Chicita Culberson, alludes to the former placement of these species in the genera Cetraria and Parmelia.

<i>Niebla</i> (lichen) Genus of lichen

Niebla is a genus of yellow-green fruticose lichens that grow on rocks, trees, and shrubs within the fog zone of coastal North America, or more narrowly defined to occur on rocks and soil along the Pacific Coast from Mendocino County in California south to Baja California Sur.

<i>Menegazzia terebrata</i> Species of lichen

Menegazzia terebrata is a species of foliose lichen found scattered across many continents, including North America, South America, Europe, Africa, and Asia.

A spot test in lichenology is a spot analysis used to help identify lichens. It is performed by placing a drop of a chemical on different parts of the lichen and noting the colour change associated with application of the chemical. The tests are routinely encountered in dichotomous keys for lichen species, and they take advantage of the wide array of lichen products produced by lichens and their uniqueness among taxa. As such, spot tests reveal the presence or absence of chemicals in various parts of a lichen. They were first proposed by the botanist William Nylander in 1866.

<span class="mw-page-title-main">Depsidone</span> Class of chemical compounds

Depsidones are chemical compounds that are sometimes found as secondary metabolites in lichens. They are esters that are both depsides and cyclic ethers. An example is norstictic acid.

<span class="mw-page-title-main">Umbilicaric acid</span> Chemical compound

Umbilicaric acid is an organic polyphenolic carboxylic acid made by several species of lichen. It is named after Umbilicaria. Umbilicaric acid is a tridepside, containing three phenol rings.

Remototrachyna is a genus of foliose lichens in the large family Parmeliaceae. It was separated from the genus Hypotrachyna based on the structure of the excipulum and genetic differences.

<i>Cladonia digitata</i> Species of lichen

Cladonia digitata, commonly known as the finger cup lichen, is a cup lichen species in the family Cladoniaceae.

<i>Cladonia squamosa</i> Species of lichen

Cladonia squamosa or the dragon cup lichen is a species of cup lichen in the family Cladoniaceae.

<span class="mw-page-title-main">Atranorin</span> Chemical compound

Atranorin is a chemical substance produced by some species of lichen. It is a secondary metabolite belonging to a group of compounds known as depsides. Atranorin has analgesic, anti-inflammatory, antibacterial, antifungal, cytotoxic, antioxidant, antiviral, and immunomodulatory properties. In rare cases, people can have an allergic reaction to atranorin.

<i>Hypogymnia tubulosa</i> Species of lichen

Hypogymnia tubulosa is a species of foliose lichen in the family Parmeliaceae. Ludwig Emanuel Schaerer formally described it in 1840 as a variety of Parmelia ceratophylla. Johan Johnsen Havaas promoted it to distinct species status in 1918.

<span class="mw-page-title-main">Salazinic acid</span> Chemical compound found in some lichens

Salazinic acid is a depsidone with a lactone ring. It is found in some lichens, and is especially prevalent in Parmotrema and Bulbothrix, where its presence or absence is often used to help classify species in those genera.

<span class="mw-page-title-main">Lichexanthone</span> Chemical compound found in some lichens

Lichexanthone is an organic compound in the structural class of chemicals known as xanthones. Lichexanthone was first isolated and identified by Japanese chemists from a species of leafy lichen in the 1940s. The compound is known to occur in many lichens, and it is important in the taxonomy of species in several genera, such as Pertusaria and Pyxine. More than a dozen lichen species have a variation of the word lichexanthone incorporated as part of their binomial name. The presence of lichexanthone in lichens causes them to fluoresce a greenish-yellow colour under long-wavelength UV light; this feature is used to help identify some species. Lichexanthone is also found in several plants, and some species of fungi that do not form lichens.

Parmotrema lichexanthonicum is a species of foliose lichen in the family Parmeliaceae. Found in Brazil, it was formally described as a new species in 1997 by Sionara Eliasaro and Mónica Adler. The type specimen was collected by the first author from the Serra do Cipó ; here the lichen was found growing on a rock. The specific epithet lichexanthonicum refers to the presence of the secondary compound lichexanthone in the medulla of the lichen. Other compounds in the lichen are the depsidone salazinic acid, and the depside atranorin. A close relative to this species is Parmotrema ultralucens, which contains the same cortical and medullary metabolites.

<span class="mw-page-title-main">Sekikaic acid</span> Chemical compound found in some lichens

Sekikaic acid is an organic compound in the structural class of chemicals known as depsides. It is found in some lichens. First isolated from Ramalina sekika, it is a fairly common lichen product in Ramalina and Cladonia, both genera of lichen-forming fungi. The species epithet of the powdery lichen Lepraria sekikaica refers to the presence of this substance—a rarity in genus Lepraria.

<span class="mw-page-title-main">Barbatic acid</span> Chemical compound found in some lichens

Barbatic acid is an organic compound that is made by some lichens. It is in the structural class known as depsides. It is particularly common in the genera Usnea and Cladonia.

<i>Ramalina americana</i> Species of lichen

Ramalina americana, commonly known as the sinewed ramalina, is a pale green fruticose lichen that is found across the Northern US Midwest, extending into Southern Canada and the Eastern Seaboard. It is characterized morphologically by the presence of pseudocyphellae, straight spores, and its unique chemical diversity.

<i>Platismatia glauca</i> Species of lichen

Platismatia glauca is a common and widespread species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae.

References

  1. ↑ Ranković & Kosanić 2019, p. 1.
  2. ↑ Molnár, Katalin; Farkas, Edit (2010). "Current Results on Biological Activities of Lichen Secondary Metabolites: a Review". Zeitschrift für Naturforschung C. 65 (3–4): 157–173. doi: 10.1515/znc-2010-3-401 . PMID   20469633.
  3. ↑ Stocker-Wörgötter, Elfie; Cordeiro, Lucimara Mach Cortes; Iacomini, Marcello (2013). "Accumulation of Potential Pharmaceutically Relevant Lichen Metabolites in Lichens and Cultured Lichen Symbionts". Studies in Natural Products Chemistry. Vol. 39. Elsevier. pp. 337–380. doi:10.1016/b978-0-444-62615-8.00010-2. ISBN   978-0-444-62615-8.
  4. ↑ Stocker-Wörgötter, Elfie (2008). "Metabolic diversity of lichen-forming ascomycetous fungi: culturing, polyketide and shikimatemetabolite production, and PKS genes". Natural Product Reports. 25 (1): 188–200. doi:10.1039/b606983p. PMID   18250902.
  5. ↑ Culberson, Chicita F.; Elix, john A. (1989). "Lichen Substances". Methods in Plant Biochemistry. Vol. 1. pp. 509–535. doi:10.1016/b978-0-12-461011-8.50021-4. ISBN   9780124610118.
  6. ↑ Ranković & Kosanić 2019, p. 4.
  7. ↑ Ranković & Kosanić 2019, p. 5.
  8. ↑ Culberson, Chicita F.; Culberson, William Louis (2001). "Future directions in lichen chemistry". The Bryologist. 104 (2): 230–234. doi:10.1639/0007-2745(2001)104[0230:FDILC]2.0.CO;2. JSTOR   3244888.
  9. ↑ Kalra, Rishu; Conlan, Xavier A.; Goel, Mayurika (2021). "Lichen allelopathy: a new hope for limiting chemical herbicide and pesticide use". Biocontrol Science and Technology. 31 (8): 773–796. doi:10.1080/09583157.2021.1901071.
  10. ↑ Culberson, Chicita F.; Kristinsson, Hör-Dur (1970). "A standardized method for the identification of lichen products". Journal of Chromatography A. 46: 85–93. doi:10.1016/s0021-9673(00)83967-9.
  11. ↑ Culberson, Chicita F. (1972). "Improved conditions and new data for identification of lichen products by standardized thin-layer chromatographic method". Journal of Chromatography A. 72 (1): 113–125. doi:10.1016/0021-9673(72)80013-x. PMID   5072880.
  12. ↑ Komaty, Sarah; Letertre, Marine; Dang, Huyen Duong; Jungnickel, Harald; Laux, Peter; Luch, Andreas; Carrié, Daniel; Merdrignac-Conanec, Odile; Bazureau, Jean-Pierre; Gauffre, Fabienne; Tomasi, Sophie; Paquin, Ludovic (2016). "Sample preparation for an optimized extraction of localized metabolites in lichens: Application to Pseudevernia furfuracea" (PDF). Talanta. 150: 525–530. doi:10.1016/j.talanta.2015.12.081. PMID   26838439.
  13. ↑ Studzinska-Sroka, Elzbieta; Galanty, Agnieszka; Bylka, Wieslawa (7 November 2017). "Atranorin - An Interesting Lichen Secondary Metabolite". Mini-Reviews in Medicinal Chemistry. 17 (17): 1633–1645. doi:10.2174/1389557517666170425105727. PMID   28443519.
  14. ↑ Jaeck, Andreas. "Atranorin". www.internetchemie.info.
  15. ↑ Cheng, Bichu; Trauner, Dirk (2015-11-04). "A Highly Convergent and Biomimetic Total Synthesis of Portentol". Journal of the American Chemical Society. 137 (43): 13800–13803. doi:10.1021/jacs.5b10009. ISSN   0002-7863. PMID   26471956.
  16. ↑ Candan, Mehmet; Yılmaz, Meral; Tay, Turgay; Erdem, Murat; Türk, Ayşen Özdemir (2007-08-01). "Antimicrobial Activity of Extracts of the Lichen Parmelia sulcata and its Salazinic Acid Constituent". Zeitschrift für Naturforschung C. 62 (7–8): 619–621. doi: 10.1515/znc-2007-7-827 . ISSN   1865-7125. PMID   17913083.
  17. ↑ Manojlović, Nedeljko; Ranković, Branislav; Kosanić, Marijana; Vasiljević, Perica; Stanojković, Tatjana (October 2012). "Chemical composition of three Parmelia lichens and antioxidant, antimicrobial and cytotoxic activities of some their major metabolites". Phytomedicine. 19 (13): 1166–1172. doi:10.1016/j.phymed.2012.07.012. PMID   22921748.
  18. ↑ "Wikispaces".
  19. ↑ Harris N. J. (1961), Honors Thesis, Clark University, Worcester, Massachusetts
  20. ↑ Lendemer, James C. (2011). "A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, with notes on the type species of the genus L. incana". Mycologia. 103 (6): 1216–1229. doi:10.3852/11-032. PMID   21642343.
  21. ↑ Kukwa, Martin (2011). The lichen genus 'Ochrolechia' in Europe. Gdańsk; Sopot: Fundacja Rozwoju Uniwersytetu Gdańskiego. ISBN   978-83-7531-170-9.
  22. ↑ Stenroos, Soili (1989). "Taxonomy of the Cladonia coccifera group. 1". Annales Botanici Fennici. 26: 157–168.
  23. ↑ Timsina, Brinda A.; Hausner, Georg; Piercey-Normore, Michele D. (2014). "Evolution of ketosynthase domains of polyketide synthase genes in the Cladonia chlorophaea species complex (Cladoniaceae)". Fungal Biology. 118 (11): 896–909. doi:10.1016/j.funbio.2014.08.001. PMID   25442293.
  24. ↑ Lumbsch, H. Thorsten; Leavitt, Steven D. (2011). "Goodbye morphology? A paradigm shift in the delimitation of species in lichenized fungi". Fungal Diversity. 50 (1): 59–72. doi:10.1007/s13225-011-0123-z.

Cited literature

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.