Clavariadelphus truncatus

Description

The species of Clavariadelphus can usually be told from the other clubs by their larger size, stockier stature, and characteristic ocher to yellow-orange color. C. truncatus produces rather large fruitbodies with a wide flattened cap, which makes it look something like a chanterelle, especially when the fertile surface, which runs down the upper portion beneath the “cap,” is wrinkled.

This mushroom is edible and has a sweet taste. Old mushrooms may be spongy and soft inside. The species is high in nutrition and can be used for cooking. One field guide says that the mushroom is one of the best to eat and has a sweet flavor that is especially appealing to some people. David Arora writes that the mushroom can be sauteed and served as dessert.

Clavariadelphus truncates contains clavaric acid, which has been shown to reduce the rate of tumor development when given to mice. Clavaric acid interferes with farnesyltransferase, an enzyme implicated in tumorigenesis, which suggests that clavaric acid may have therapeutic value in the treatment of certain cancers. It has been reported that mushrooms have significant antioxidant activity.

Common names: Flat-Top Coral, Flat-Topped Coral, Truncate Club Coral.

Mushroom Identification

1. Fruiting Body

   6-15 cm tall, 2.0-8 cm wide; club-shaped; tip rounded at first, but soon flattened and sometimes depressed in age, with a rounded, uplifted margin; surface dry, smooth at first, developing irregular vertical wrinkles or grooves; light orange-yellow to orange or yellowish-brown. The mushroom has a pleasant odor and a sweet taste.

2. Flesh

   White, thin, hollow at top.

3. Spore Print

   Yellowish.

4. Spores

   9-12 x 5-7 µm, ellipsoid, smooth, hyaline, nonamyloid.

5. Habitat

   Solitary, gregarious, or in small clusters on soil in coniferous woods; late summer to autumn.

6. Chemical Reactions

   Flesh turns green in FeSO4.

Medicinal Properties

Anti-tumor effects

Farnesyl-protein transferase (FPTase) is an enzyme that catalyses the transfer of the isoprenoid farnesyl to various cellular proteins, a process that is essential to establishing the proper cellular location and activity of the modified proteins. Included among these modified proteins is Ras, a protein that when farnesylated has tumor-causing properties. Inhibition of FPTase activity is known to reduce tumor development in mice, suggesting that FPTase is a viable therapeutic target in human cancers, especially in leukemias and pancreatic and colon carcinomas, where mutated ras-oncogenes are often found. Research has shown that the triterpenoid clavaric acid, a fungal metabolite found in C. truncatus, inhibits FTPase, with an IC50 = 1.3 µM (Jayasuriya et al., 1998; Lingham et al., 1998).

Clavaric acid, the FTPase-inihibiting anti-tumor compound from the medicinal mushroom Clavariadelphus truncatus

Antibacterial activity

Using the disk diffusion and microdilution methods, the antimicrobial activity of C. truncatus was evaluated (Yamac and Bilgili, 2006). Aqueous and organic extracts of the club mushroom had a broad antibacterial spectrum, showing weak activity against the Gram-negative bacteria Escherichia coli, Enterobacter aerogenes and Salmonella typhimurium. Both extracts were also antibacterial towards Staphylococcus aureus and Bacillus subtilis; the spectrum and levels of antimicrobial activity were similar to that of the positive control, ceftriaxone. The antibiotic activity was not sensitive to heat treatment (i.e. heating at 60°C for 30 min or 100°C for 5 min).

Photo sources:

Photo 1 - Author: amadej trnkoczy (amadej) (CC BY-SA 3.0)

Photo 2 - Author: Clavariadelphus_truncatus_2.jpg: Gerhard Koller (Gerhard)derivative work: Natr (talk) (CC BY-SA 3.0)

Photo 3 - Author: Holger Krisp (CC BY 3.0)