[2] Orellanine comes from a class of mushrooms that fall under the genus Cortinarius, and has been found in the species C. orellanus, rubellus, henrici, rainerensis and bruneofulvus.

[3][5] Grzymala was also able to demonstrate the nephrotoxicity of C. orellanus and determine various physical and chemical properties of orellanine.

[7] The following year, Tiecco et al. reported the total synthesis of orellanine in nine steps starting from 3-hydroxypyridine.

[3][10] Orellanine displays a wide spectrum of toxin effects in plants, animals, and microorganisms.

[3] Although the mechanism of toxicity of orellanine is not yet fully understood, it likely targets cellular processes found in both prokaryotes and eukaryotes.

[3] In humans, a characteristic of poisoning by the nephrotoxin orellanine is the long latency; the first symptoms usually do not appear until 2–4 to 14 days after ingestion.

[3] The first symptoms of orellanine poisoning are similar to the common flu (nausea, vomiting, stomach pains, headaches, myalgia, etc.

The LD50 of orellanine in mice is 12 to 20 mg per kg body weight;[11][12] this is the dose which leads to death within two weeks.