9 research outputs found
Aphanizomenon gracile (Nostocales), a cylindrospermopsin-producing cyanobacterium in Polish lakes
Phytoplankton composition, biodiversity and a pilot survey of toxic cyanoprokaryotes in a large cascading reservoir system (TietĂŞ basin, Brazil)
Short ingestion tests as alternative proposal for conventional range finding assays with Thamnocephalus platyurus and Brachionus calyciflorus
Determination of the toxicity of the freshwater cyanobacterium Woronichinia naegeliana (Unger) Elenkin
Multiple Toxin Production in the Cyanobacterium Microcystis : Isolation of the Toxic Protease Inhibitor Cyanopeptolin 1020
The isolation and structure of cyanopeptolin 1020 (hexanoic acid-Glu-N[-O-Thr-Arg-Ahp-Phe-N-Me-Tyr-Val-]) from a Microcystis strain is reported. Very potent picomolar trypsin inhibition (IC50 = 670 pM) and low nanomolar values against human kallikrein (4.5 nM) and factor XIa (3.9 nM) have been determined for cyanopeptolin 1020. For plasmin and chymotrypsin, low micromolar concentrations were necessary for 50% inhibition. Cyanopeptolin 1020 was found to be toxic against the freshwater crustaceanThamnocephalus platyurus (LC50 = 8.8 μM), which is in the same range as some of the well-known microcystins. These data support the hypothesis that cyanopeptolins can be considered as a second class of toxins in addition to the well-established microcystins inMicrocystis