Microcystin



Microcystins are cyclic nonribosomal peptides produced by cyanobacteria. They are cyanotoxins and can be very toxic for plants and animals including humans. Their hepatotoxicity may cause serious damage to the liver.

Microcystins consist of several uncommon non-proteinogenic amino acids such as dehydroalanine derivatives and the special β-amino acid ADDA ((all-S,all-E)-3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-diene acid).

There appears to be inadequate information to assess carcinogenic potential of microcystins by applying EPA Guidelines for Carcinogen Risk Assessment. A few studies suggest that there may be a relationship between liver and colorectral cancers and the occurrence of cyanobacteria in drinking water in China (Yu et al., 1989; Zhou et al., 2002). Evidence is, however, limited due to limited ability to accurately assess and measure exposure.