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Titolo:
High grazer toxicity of [D-Asp(3) (E)-Dhb(7)]microcystin-RR of Planktothrix rubescens as compared to different microcystins
Autore:
Blom, JF; Robinson, JA; Juttner, F;
Indirizzi:
Univ Zurich, Inst Pflanzenbiol, Limnol Stn, CH-8802 Kilchberg, SwitzerlandUniv Zurich Kilchberg Switzerland CH-8802 CH-8802 Kilchberg, Switzerland Univ Zurich, Inst Organ Chem, CH-8057 Zurich, Switzerland Univ Zurich Zurich Switzerland CH-8057 Chem, CH-8057 Zurich, Switzerland
Titolo Testata:
TOXICON
fascicolo: 12, volume: 39, anno: 2001,
pagine: 1923 - 1932
SICI:
0041-0101(200112)39:12<1923:HGTO[(>2.0.ZU;2-I
Fonte:
ISI
Lingua:
ENG
Soggetto:
BLUE-GREEN-ALGAE; OSCILLATORIA-AGARDHII; ARTEMIA-SALINA; PEPTIDE TOXIN; DANIO-RERIO; LR; AERUGINOSA; CYANOBACTERIA; STRAINS; IDENTIFICATION;
Keywords:
Planktothrix rubescens; [D-Asp(3),(E)-Dhb(7)]microcystin-RR; molar absorption coefficient; Thamnocephalus platyurus bioassay;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Blom, JF Univ Zurich, Inst Pflanzenbiol, Limnol Stn, Seestr 187, CH-8802 Kilchberg,Switzerland Univ Zurich Seestr 187 Kilchberg Switzerland CH-8802 Switzerland
Citazione:
J.F. Blom et al., "High grazer toxicity of [D-Asp(3) (E)-Dhb(7)]microcystin-RR of Planktothrix rubescens as compared to different microcystins", TOXICON, 39(12), 2001, pp. 1923-1932

Abstract

Planktothrix rubescens, the dominant cyanobacterium in Lake Zurich, is generally considered to be toxic to zooplankton. The major toxin was determined by NMR spectroscopy and chemical analysis to be [D-Asp(3), (E)-Dhb(7)]microcystin-RR. The compound was isolated in high purity, and its 24-h acute grazer toxicity was compared with microcystin-LR, microcystin-RR, microcystin-YR, and nodularin using a Thamnocephalus platyurus bioassay. Based on LC50 values [D-Asp(3),(E)-Dhb(7)]microcystin-RR was the most toxic microcystintested. Nodularin was slightly more toxic under the conditions of the assay. The large number of individuals available for the grazer bioassay allowed the determination of dose-response curves of the different microcystins. These curves showed marked differences in their steepness. Microcystin-RR, which had nearly the same LC50 as microcystin-LR and microcystin-YR, exhibited a very flat dose-response curve. This flat curve indicates that, for some individuals, lower concentrations of this microcystin are much more toxic than are the other two microcystins. Mortality of 100% requires much higher concentrations of microcystin-RR, indicating the resistance of some animals to the toxin. The purified [D-Asp(3), (E)-Dhb(7)]microcystin-RR exhibited a higher molar absorption coefficient determined by quantitative amino acid analysis than the coefficients generally used for other microcystins. This observation has consequences for the risk assessment for microcystins and makes a structural determination of microcystins an absolute requirement. The presence of the dehydrobutyrine residue may be the reason for the higher specific toxicity of [D-Asp(3), (E)-Dhb(7)]microcystin-RR when comparedto the N-methyldehydroalanine-containing microcystins. (C) 2001 Elsevier Science Ltd. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/04/20 alle ore 19:17:20