Rhodocollybia maculata, commonly known as the spotted toughshank, is a North American species of basidiomycete fungus in the family Omphalotaceae.[2] R. maculata is a source of collybolide, a sesquiterpenoid containing a furyl-ẟ-lactone motif reminiscent of salvinorin A.

Description

The cap is up to 9 centimetres (3+1⁄2 in) wide and cream-colored with red-brown spots.[3] The edge remains inrolled for an extended period of time. The whitish gills are crowded, becoming spotted in age. The similarly colored stipe is up to 10 cm long,[3] tough, hollow, and tapered downwards.[4] The spore print is whitish to yellowish.[3]

A variety known as scorzonerea is characterized by yellowish color of its gills, and sometimes the stipe.[4]

Distribution and habitat

It is widespread in North America.[3] It often appears in decomposing conifer duff.[4]

Edibility

Though non-toxic,[5] this species is considered inedible due to its toughness and unpalatability;[6] it is typically bitter.[7]

Kappa-opioid receptor agonism

Main article: Collybolide

In 2016, Gupta et al. reported that collybolide exhibited high-potency, selective kappa-opioid receptor (KOR) agonism.[8] Due to its attractive bioactivity and chemical similarity to salvinorin A, collybolide garnered attention in the synthetic chemistry and pharmacology fields as a potential scaffold for developing next-generation analgesics, antipruritics, and antidepressants.[9][10][11]

In 2022, Shevick et al. completed the first enantioselective total synthesis of collybolide and profiled the activity of synthetic collybolide at the KOR. Despite previous findings by Gupta et al., these assays showed that neither enantiomer of collybolide had KOR activity.[12] The synthetic sample was identical to natural collybolide isolated from R. maculata. Assays of crude R. maculata extracts by other groups additionally showed no KOR activity.[12][Note 1] These assays of synthetic and natural samples contradict the findings of Gupta et al., and suggest that collybolide and the other constituents of R. maculata have no activity at KOR.

Notes

  1. ^ See page 150 of the Supporting Information of Shevick et al. for reports on the kappa-opioid receptor assays with crude R. maculata extracts.

References

  1. ^ Bates ST. "Rhodocollybia maculata (Alb. & Schwein.: Fr.) Singer". Arizona State University. Archived from the original on 2012-03-31.
  2. ^ Kuo M (March 2018). "Rhodocollybia maculata". MushroomExpert.Com.
  3. ^ a b c d Audubon (2023). Mushrooms of North America. Knopf. p. 479. ISBN 978-0-593-31998-7.
  4. ^ a b c Trudell S, Ammirati J (2009). Mushrooms of the Pacific Northwest. Timber Press Field Guides. Portland, OR: Timber Press. p. 120. ISBN 978-0-88192-935-5.
  5. ^ Miller Jr OK, Miller HH (2006). North American Mushrooms: A Field Guide to Edible and Inedible Fungi. Guilford, CN: FalconGuide. p. 176. ISBN 978-0-7627-3109-1.
  6. ^ Phillips R (2010). Mushrooms and Other Fungi of North America. Buffalo, NY: Firefly Books. p. 73. ISBN 978-1-55407-651-2.
  7. ^ Wood M, Stevens F. "Rhodocollybia maculata". The Fungi of California.
  8. ^ Gupta A, Gomes I, Bobeck EN, Fakira AK, Massaro NP, Sharma I, et al. (May 2016). "Collybolide is a novel biased agonist of κ-opioid receptors with potent antipruritic activity". Proceedings of the National Academy of Sciences of the United States of America. 113 (21): 6041–6046. Bibcode:2016PNAS..113.6041G. doi:10.1073/pnas.1521825113. PMC 4889365. PMID 27162327.
  9. ^ Khan MI, Sawyer BJ, Akins NS, Le HV (December 2022). "A systematic review on the kappa opioid receptor and its ligands: New directions for the treatment of pain, anxiety, depression, and drug abuse" (PDF). European Journal of Medicinal Chemistry. 243: 114785. doi:10.1016/j.ejmech.2022.114785. PMID 36179400. S2CID 252476850.
  10. ^ Chakraborty S, Majumdar S (May 2021). "Natural Products for the Treatment of Pain: Chemistry and Pharmacology of Salvinorin A, Mitragynine, and Collybolide". Biochemistry. 60 (18): 1381–1400. doi:10.1021/acs.biochem.0c00629. PMC 7982354. PMID 32930582.
  11. ^ Bui AM, Cavé A, Janot MM, Parello J, Potier P, Scheidegger U (1974-01-01). "Isolement et analyse structurale du collybolide, nouveau sesquiterpene extrait de Collybia maculata alb. et sch. ex fries (basidiomycetes)" [Isolation and structural analysis of collybolide, a new sesquiterpene extracted from Collybia maculata alb. and sch. ex fries (basidiomycetes)]. Tetrahedron (in French). 30 (11): 1327–1336. doi:10.1016/S0040-4020(01)97243-6. ISSN 0040-4020.
  12. ^ a b Shevick SL, Freeman SM, Tong G, Russo RJ, Bohn LM, Shenvi RA (July 2022). "Asymmetric Syntheses of (+)- and (-)-Collybolide Enable Reevaluation of kappa-Opioid Receptor Agonism". ACS Central Science. 8 (7): 948–954. doi:10.1021/acscentsci.2c00442. PMC 9335922. PMID 35912357.
Allikas: https://en.wikipedia.org/wiki/Rhodocollybia_maculata
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