Microcystins are a group of cyclic heptapeptide hepatotoxins produced by a number of cyanobacterial genera. The most notable of which, and namesake, is the widespread genus Microcystis. Structurally, all microcystins consist of the generalized structure cyclo(-D-Ala1-X2-D-MeAsp3-Y4-Adda5-D-Glu6-Mdha7-). X and Y are variable L-amino acids, D-MeAsp is D-erythro-ß-methylaspartic acid and Mdha is N-methyldehydroalanine. Adda is the cyanobacteria unique C20 ß-amino acid 3-amino-9-methoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid. Substitutions of the variable L-amino acids at positions 2 and 4 give rise to at least 21 known primary microcystin analogs and alterations in the other constituent amino acids result in more than 90 reported mycrocystins to date.

Analog of microcystin-LR (Prod. No. ALX-350-012) with Phe substituted in place of Arg. Hydrophobic and believed to be more cell permeable than other microcystins. More toxic than the more hydrophilic analogs such as microcystin-LR and microcystin-LY.

Isolated from Microcystis aeruginosa.