(Schwein.) Bresinsky & Besl
|gills on hymenium|
|cap is infundibuliform|
|hymenium is decurrent|
|stipe is bare|
|spore print is yellow|
|ecology is saprotrophic|
Omphalotus illudens is commonly called the jack-o'lantern mushroom. It is a large orange mushroom that is often found in clumps on decaying stumps, buried roots or at the base of hardwood trees in eastern North America. Its gills often exhibit a weak green bioluminesence when fresh.
Omphalotus illudens is sometimes confused with edible chanterelles, but is poisonous to humans when eaten, whether raw or cooked, and typically causes vomiting, cramps, and diarrhea. Although some older literature claims the name is synonymous with Omphalotus olearius, phylogenetic analysis confirms they are distinct species.
The poisonous chemical compounds illudin S and illudin M were isolated from Omphalotus illudens. In addition to their antibacterial and antifungal effects, illudins appear to be the cause of human toxicity when these mushrooms are eaten raw or cooked. Muscarine has also been indirectly implicated in toxicity, but modern studies to demonstrate its presence in O. illudens are needed.
The cytotoxic effect of illudin is of interest for treating some cancers, but illudin itself is too poisonous to use directly so it must first be chemically modified. Inside human cells, illudin S reacts with DNA and creates a type of DNA damage that blocks transcription. This block can only be relieved by a repair system called nucleotide excision repair. Damage in non-transcribed DNA areas is left unrepaired by the cell. This property was exploited by the company MGI Pharma to develop an illudin-derivative called Irofulven for use as a cancer treatment. Its application is still in the experimental phase.
- Kirchmair M, Morandell S, Stolz D, Pöder R, Sturmbauer C. (2004). "Phylogeny of the genus Omphalotus based on nuclear ribosomal DNA-sequences". Mycologia 96 (6): 1253–60. doi:10.2307/3762142. JSTOR 3762142. PMID 21148949. Retrieved 2010-05-26.
- Anchel, M,; Herbey, A.; Robbins, W.J. (1950). "Antibiotic Substances from Basidiomycetes: VII. Clitocybe illudens". Proceedings of the National Academy of Sciences of the United States of America 36 (5): 300–305.
- McMorris, T. C.; Kelner, M. J.; Wang, W.; Estes, L. A.; Montoya, M. A.; Taetle, R. (1992). "Structure-Activity Relationship of Illudins : Analogs with Improved Therapeutic Index". Journal of Organic Chemistry 57 (25): 6876–6883. doi:10.1021/jo00051a037.
- Clark, Ernest D.; Smith, Clayton S. (1913). "Toxicological Studies on the Mushrooms Clitocybe illudens and Inocybe infida". Mycologia 5 (4): 224–232. JSTOR 3753387.