Harada K, Ogawa K, Matsuura K, Nagai H, Murata H, Suzuki M, Itezono Y, Nakayama N, Shirai M, Nakano M
Faculty of Pharmacy, Meijo University, Nagoya, Japan.
Toxicon. 1991;29(4-5):479-89. doi: 10.1016/0041-0101(91)90022-j.
Two toxic heptapeptides were isolated from an axenic Microcystis aeruginosa strain, K-139. Using mainly a non-destructive NMR method, we determined the structure of the major toxin to be 7-desmethylmicrocystin LR which lacks an N-methyl group of the dehydroalanine moiety of microcystin LR. The minor toxin was deduced to be 3,7-didesmethylmicrocystin LR. The chromatographic and NMR analyses of 7-desmethylmicrocystin LR were compared with those of 3-desmethylmicrocystin LR.
