Toxic Fungi of Western North America

by Thomas J. Duffy, MD

Toxins of Cortinarius orellanus

An extract of Cortinarius orellanus has yielded a crystalline substance—orellanine. Orellanine now appears to be a group of bipyridyl compounds. (127,128) Dried specimens of Cortinarius orellanus have retained toxicity up to 60 years. (129) A major effect of orellanine is on alkaline phosphatase, an enzyme system required for the energy derived from transport of phosphate into cells. The energy-producing organelles in cells known as mitochondria are the most damaged. (22)

Orellanine
Figure 7. Orellanine

Another group has described the presence of compounds similar to the amatoxins. (130) Orellanine was not always present and a group of cyclopeptides, named cortinarins, was proposed. The presence of cortinarin A and cortinarin B, however, was not confirmed by later studies. (131)

Other than chromatography, two qualitative tests have been described. In the first, the fresh or dried mushroom is crushed in water and after 10 minutes the mixture is filtered. The filtered solution is mixed in equal portions with 3% ferric chloride hexahydrate dissolved in 0.5 N hydrochloric acid. A dark gray blue color suggests orellanine. (132) Pöder and Moser have proposed a more rapid test on fresh or dried specimens. (133) The fresh, dried or even cooked specimen is added to a small amount of water, just enough to pound or grind to a pulp. The mixture is then centrifuged to obtain the liquid test material. A drop of this liquid is then placed onto previously prepared white blotting paper or laboratory "bibulous paper" (paper used to mop up excess fluid from microscope slides). The bibulous paper is pretreated by soaking with a 2 percent solution of ferric chloride in 0.5 N HCl acid and allowed to dry. A control spot is done on a second piece of non-treated bibulous paper. A positive test for orellanine is one showing a central reddish color with an encircling lilac halo.