Mycotoxin reference
Indoor-relevant mycotoxins.
Mycotoxins are low-molecular-weight secondary metabolites produced by molds as a byproduct of growth. They are chemically diverse (polyketides, terpenoids, alkaloids), and their biological activity depends entirely on chemistry, not on the organism that produced them. Reference pages below cover the mycotoxins most relevant to indoor mold exposure and to the organisms on the standard ERMI panel and on extended commercial panels.
Note: these pages describe mycotoxins as molecules: what they are, what produces them, where they occur. They do not interpret urine test results, recommend specific testing, or provide clinical advice.
The 11 mycotoxins
Mycotoxin
Aflatoxins
A family of difuranocoumarin secondary metabolites produced primarily by Aspergillus flavus and A. parasiticus. Aflatoxin B1 is the most potent natural carcinogen characterized; IARC Group 1.
Mycotoxin
Ochratoxin A
Nephrotoxic pentaketide produced by Aspergillus ochraceus, Penicillium verrucosum, and several related species. The most frequently detected mycotoxin in human dietary exposure surveys globally.
Mycotoxin
Trichothecenes
A family of >200 sesquiterpenoid mycotoxins that inhibit eukaryotic protein synthesis. Macrocyclic (Type D) variants from Stachybotrys dominate indoor water-damage contexts; simple (Type A/B) variants from Fusarium dominate cereal contamination.
Mycotoxin
Gliotoxin
Immunosuppressive epipolythiodioxopiperazine mycotoxin produced principally by Aspergillus fumigatus and some A. terreus strains. Disulfide bridge is essential for activity.
Mycotoxin
Zearalenone
Non-steroidal mycoestrogen produced by Fusarium graminearum and related cool-temperate grain species. Binds vertebrate estrogen receptors despite differing chemistry.
Mycotoxin
Fumonisins
Sphinganine-analog polyketides produced by Fusarium verticillioides and F. proliferatum on corn. Disrupt sphingolipid biosynthesis by inhibiting ceramide synthase.
Mycotoxin
Sterigmatocystin
Dihydrobisfuran-fused xanthone produced primarily indoors by Aspergillus versicolor. The penultimate biosynthetic intermediate of the aflatoxin pathway.
Mycotoxin
Citrinin
Polyketide-derived yellow pigment with nephrotoxic activity. Produced by Penicillium citrinum, P. expansum, and Aspergillus terreus. Frequently co-occurs with ochratoxin A.
Mycotoxin
Patulin
Highly reactive unsaturated lactone produced by Penicillium expansum on damaged apples. Documented indoor emission from P. expansum on gypsum board.
Mycotoxin
Chaetoglobosins
Cytochalasin-family macrocyclic alkaloids produced principally by Chaetomium globosum on water-damaged cellulose. Bind actin filaments and disrupt cytoskeletal function.
Mycotoxin
Mycophenolic acid
Phthalide-derived metabolite produced by Penicillium brevicompactum and P. roqueforti. The same molecule is used clinically as the immunosuppressant mycophenolate mofetil.