page_title: Citrinin
section_title: Structure & reactivity
hierarchical_section_title: Citrinin / Structure & reactivity
caption_attribution_description: English: Based on the article of Clark BR et al.
context_page_description: Citrinin is a mycotoxin which is often found in food. It is a secondary metabolite produced by fungi that contaminate long-stored food and it causes different toxic effects, like nephrotoxic, hepatotoxic and cytotoxic effects. Citrinin is mainly found in stored grains, but sometimes also in fruits and other plant products.
context_section_description: Citrinin is a polyketide mycotoxin, which is a secondary metabolite of some fungi species. Its IUPAC  name is (3R,4S)-4,6-dihydro-8-hydroxy-3,4,5-trimethyl-6-oxo-3H-2-benzopyran-7-carboxylic acid and the molecular formula is C₁₃H₁₄O₅. Citrinin has a molecular weight of 250.25 g/mol. It forms disordered yellow crystals which melt at 175 °C. Citrinin is a planar molecule which contains conjugated bonds. As a result of these conjugated bonds citrinin is autofluorescent. Citrinin crystals can hardly be dissolved in cold water, however in polar organic solvents and aqueous sodium hydroxide, sodium carbonate and sodium acetate dissolving is possible.
  As stated above, citrinin decomposes at temperatures higher than 175 °C, providing that it is under dry conditions. When water is present, the decomposition temperature is around 100 °C. Several decomposition products of citrinin are known, including phenol A, citrinin H1, citrinin H2 and dicitrinin A. The structures of the decomposition products are shown in figure 1, depicted on the left. Citrinin H1 is produced out of two citrinin molecules and its toxicity is increased compared to the original toxicity of citrinin. Citrinin H2, a formylated derivative of phenol A, is less toxic than citrinin. Phenol A seems to be produced mainly under acidic conditions. Dicitrinin A is a dimer of citrinin molecules which is mainly formed during decomposition in a neutral environment, when a high concentration of citrinin is present.
  The way citrinin reacts in the body is not understood yet and its intermediates during biotransformation are also not known.
caption: Figure 1: Structures of citrinin and its decomposition products. Based on Clark B.R. et al. (2006) [8]