Necatorin
Necatorin is a highly mutagenic chemical compound with the molecular formula. It is found in some mushrooms including Lactarius turpis, from which it was first isolated and characterized. It tests positive in the Ames test, an assay for mutagenicity. Crude extracts of L. necator are also highly mutagenic in a bacterial test system, and this effect it attributed to necatorin.
Necatorin is present in L. necator at concentrations of 3 to 20 mg/kg, and blanching the mushroom can reduce it to about 25% of its original amount. In boiling water, the chemical compound is stable except under acidic conditions.