Microcystins from Anabaena flos-aquae NRC 525-17

Abstract

Anabaena flos-aquae NRC 525-17 produces a very potent neurotoxin, anatoxin-a(s). During isolation of the neurotoxin, we found that the strain contains four other toxic compounds which show strong hepatotoxicity. The four toxins, toxins 1, 1', 2, and 3, were successfully purified. Toxin 2, one of major toxins, was identified as 3-desmethylmicrocystin LR (1) by comparison of spectral data of the known compound. Since the three other toxins contain an unknown amino acid, GC/MS was applied and it revealed the presence of homotyrosine in toxins 1 (2) and 1' (3). Only a partial structure was obtained for toxin 3 due to the small amount present in the cells.

Direct Evidence for Production of Microcystins by Anabaena Strains from the Baltic Sea

“…We identified variant B as MCYST-HtyR ( Fig. 2 and 3), which has been documented from Anabaena flos-aquae NRC 525-17 (12) and is the only variant having an m/z value of 1,059. Variants C and D were classified as [D-Asp 3 ]MCYST-LR and MCYST-LR, respectively ( Fig.…”

Production of Secondary Metabolites by Freshwater Cyanobacteria

“…5a. 14) In the next step we have to differentiate microcystins from other type-compounds. For this purpose LC/MS is quite effective, because any microcystin gives a common characteristic fragment ion, m/z 135, which is derived from the Adda ((2S,3S,8S,9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4(E),6(E)-dienoic acid) portion and this is available for the differentiation of microcystins from other typecompounds.…”

Natural occurrence of microcystin synthetase deletion mutants capable of producing microcystins in strains of the genus Anabaena (Cyanobacteria)

“…Strains of the genus Anabaena produce a broad range of N-methylated microcystins Halinen et al, 2007;Harada et al, 1991;Krishnamurthy et al, 1989;Sivonen et al, 1992a, b). It has been shown in several studies that strains of the genus Anabaena produce mixtures of microcystins, some of which lack the N-methyl group (Halinen et al, 2007;Namikoshi et al, 1992aNamikoshi et al, , b, 1998Sivonen et al, 1992a, b).…”