Further Characterization of Glycine-Containing Microcystins from the McMurdo Dry Valleys of Antarctica

Toxins

Patrick T. Holland¹  Susanna A. Wood¹  Jonathan Puddick¹  Stephen Craig Cary²  Michèle R. Prinsep³  David P. Hamilton⁴ 

[1] Cawthron Institute, Private Bag 2, Nelson 7010, New Zealand;Department of Biological Sciences, School of Science, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand;Department of Chemistry, School of Science, University of Waikato, Private Bag 3105,Hamilton 3240, New Zealand;Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton 3240,New Zealand;

关键词: microcystin;    Antarctica;    amino acid analysis;    mass spectrometry;    thiol derivatization;   

DOI  :  10.3390/toxins7020493

来源: DOAJ

【 摘 要 】

Microcystins are hepatotoxic cyclic peptides produced by several cyanobacterial genera worldwide. In 2008, our research group identified eight new glycine-containing microcystin congeners in two hydro-terrestrial mat samples from the McMurdo Dry Valleys of Eastern Antarctica. During the present study, high-resolution mass spectrometry, amino acid analysis and micro-scale thiol derivatization were used to further elucidate their structures. The Antarctic microcystin congeners contained the rare substitution of the position-1 ᴅ-alanine for glycine, as well as the acetyl desmethyl modification of the position-5 Adda moiety (3S-amino-9S-methoxy-2S,6,8S-trimethyl-10-phenyldeca-4E,6E-dienoic acid). Amino acid analysis was used to determine the stereochemistry of several of the amino acids and conclusively demonstrated the presence of glycine in the microcystins. A recently developed thiol derivatization technique showed that each microcystin contained dehydrobutyrine in position-7 instead of the commonly observed N-methyl dehydroalanine.

【 授权许可】

Unknown