Toxins contained in Microcystis species of cyanobacteria (blue-green algae)

M. F. Watanabe, S. Oishi, K. Harada, K. Matsuura, H. Kawal and M. Suzuki. Toxins contained in Microcystis species of cyanobacteria (blue-green algae). Toxicon 26, 1017–1025, 1988. — Cyclic peptide toxins were analyzed for three Microcystis species ( M. aeruginosa, M. viridis and M. wesenbergii) using an ODS-silica gel cartridge and high performance liquid chromatography with ODS-silica gel. One strain of M. aeruginosa contained a high amount of microcystin (cyanoginosin) YR and a lesser amount of LR. Three toxins, microcystin-RR, -YR and -LR, were detected in two strains of M. aeruginosa and four of M. viridis. The main component of the toxins of these strains was microcystin-RR. M. wesenbergii showed no peak in the area where the three toxins were obtained in other Microcystis species by HPLC analysis. ld 50 values of the purified toxins of YR and LR were similar, while a lower toxicity was estimated for RR. This explains the relatively weak toxicity of M. viridis whose main component is microcystin-RR.