FIRST REPORT OF MICROCYSTINS IN TAIWAN

This is the first report on microcystins from Microcystis aeruginosa K utzing in Taiwan. A total of nine strains of cyanobacteria have been i solated from eutrophic aquaculture ponds and water reservoirs. By mous e toxicity assay, six of the nine strains had LD100 in the range of 25 -100 mg per kg mouse for dried bacterial mass. Microcystin-LR and -RR were found in all toxic strains and their contents ranged from 0.11-10 .06 mu g and 0.08-2.21 mu g per mg of dried bacteria, respectively. Mi crocystin-RA, a minor component found only in M. TN-2 and M. CY-1 stra ins, was identified as a new microcystin. All three toxins wore isolat ed by a serial separation on an LH-20 column: Si-flash column chromato graphy and reverse phase HPLC. Toxins were further identified by compa ring their FABMS, H-1 and H-1-H-1 COSY NMR spectra with the authentic microcystin-LR. Several other microcystin-like compounds were also fou nd in the cultured strains and their structures are being determined. (C) 1998 Elsevier Science Ltd. All rights reserved.