One variant of microcystins was isolated and purified with cyanobacteria natural bloom as the starting material, which was collected in Dianchi Lake, China. The separation protocol involved extraction of cyanobacterial cells by 75% aqueous methanol, isolation by reversed-phase flash chromatography, and purification by reversed-phase semipreparative HPLC. The structure and purity of purified microcystin was identified with electrospray ionization mass spectrometry, UV spectrophotometer, and analytical HPLC. The purified microcystin was assigned as [Dha7]MCRR (purity > 95%), which was a demethylated variant of MCRR. The structure of purified microcystin was identified as cyclo-(Ala-Arg-MeAsp-Arg-Adda-Glu-Dha) with molecular weight of 1023. There was a maximum absorbance at 239 nm in its UV spectrum (200-300 nm). This variant of microcystins occurred frequently, and sometimes could become the main variant in waterbloom from Dianchi Lake.
Download full-text PDF |
Source |
---|
Chemosphere
October 2024
Blue Growth Research Lab, Ghent University, Bluebridge, Wetenschapspark 1, 8400, Ostend, Belgium.
Harmful algal blooms (HABs) - proliferated algae densities, often producing toxins - have increasingly been found in ocean and coastal areas. Recent studies show that rising temperatures contribute to HAB occurrence, but the broader influence of climate change on these outbreaks is less quantified. Of particular concern is the limited research on HAB toxin effects under varying temperatures, especially regarding primary consumers such as copepods, a crucial component of aquatic ecosystems.
View Article and Find Full Text PDFAquat Toxicol
August 2024
Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf 8600, Switzerland. Electronic address:
The mass proliferation of cyanobacteria, episodes known as blooms, is a concern worldwide. One of the most critical aspects during these blooms is the production of toxic secondary metabolites that are not limited to the four cyanotoxins recognized by the World Health Organization. These metabolites comprise a wide range of structurally diverse compounds that possess bioactive functions.
View Article and Find Full Text PDFFood Chem
September 2024
College of Food and Pharmaceutical Sciences, School of Physical Science and Technology, Ningbo University, Ningbo 315211, Zhejiang, PR China. Electronic address:
As a hypertoxic natural toxin, the risk of Microcystin-leucine-arginine (MC-LR) residues in Bellamya aeruginosa deserves more attention. Herein, employing the conventional thin-layer chromatography (TLC) technology and a novel surface-enhanced Raman scattering (SERS) substrate, a TLC-SERS chip was fabricated for the purification and quantitative detection of MC-LR in complex samples. The substrate exhibited excellent SERS performance with an enhancement factor of 6.
View Article and Find Full Text PDFSci Total Environ
June 2024
Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; WATEC, Centre for Water Technology, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark.
Harmful cyanobacterial blooms have increased globally, releasing hazardous cyanotoxins that threaten the safety of water resources. Constructed wetlands (CWs) are a nature-based and low-cost solution to purify and remove cyanotoxins from water. However, bio-mechanistic understanding of the biotransformation processes expected to drive cyanotoxin removal in such systems is poor, and primarily focused on bacteria.
View Article and Find Full Text PDFSci Total Environ
February 2024
School of Geography and Tourism, Qufu Normal University, Rizhao 276826, China.
The risks of planktonic cyanobacteria blooms have been the focus of much scientific research, but studies on the ecotoxicological effects of benthic cyanobacteria are lagging. The impacts of cyanobacteria cells on fish populations might be more complex in contrast to purified cyanotoxins or cyanobacteria extracts. This study systematically compared the chronic effects of benthic Oscillatoria sp.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!