Fungal toxins

Toxins from fungi are widely grouped into toxins from moulds (“mycotoxins”) and toxins from higher fungi (“mushroom poisons”). This is a rather vague differentiation and not based on scientific taxonomy. Our work is focused on different aspects of mycotoxin chemistry, their biological effects and, to a lesser extent, ecological role.

Mycotoxins

There are many definitions for what a mycotoxin is. Mycotoxins have for example been defined as “natural products from moulds that evoke a toxic response when introduced in low concentrations to vertebrates”. Mycotoxins are products of a fungus’ secondary metabolism, i.e. that part of fungal metabolism that is not essential for cell growth and maintainance of basic cell function. Why fungi produce such substances is not entirely clear, but they may, at least in part, be used for “chemical warfare” and thus provide some advantage to survive in the environment.

Important groups of mycotoxins

Ergot alkaloids Aflatoxins Ochratoxins
mainly produced by fungi within the Clavicipitaceae produced by several Aspergillus spp primarily produced by Aspergillus and Penicillium spp
cause ergotism hepatotoxic, strongest natural carcinogens nephrotoxins, immune suppresive

 

Fumonicins Trichotecenes Zearalenone
mainly producers Fusarium verticilliodes and F. proliferatum produced by Fusarium spp, four subgroups: type-A – D produced by Fusarium spp
hepatotoxic, leukoencephalomalacia (horse) cytotoxic, inhibit protein- and DNA-synthesis mycoestrogen

Mushroom poisons

Mushroom poisoning is commonly caused after consumption of raw or cooked fruit bodies of toxic species. Poisonous mushrooms are often referred to as toadstools from the German word “Todesstuhl” (= death’s stool). Mushroom toxins may be classified into four groups according to their principal biological effect:

protoplasmic poisons neurotoxins gastrointestinal irritants disulfiram-like toxins
generalised destruction of cells followed by organ failure profuse sweating, coma, convulsions, hallucinations nausea, vomiting, abdominal cramps, diarrhoea producers of coprine, only toxic when alcohol is consumed within approx. 72 h of ingestion
e.g. false morel (Gyramitra esculenta) e.g. deadly fibercap (Inocybe erubescens) e.g. brown rollrim (Paxillus involutus) e.g. common ink cap (Coprinus atramentarius)

DON

Enniatin