Publications: Peer-reviewed journal articles (by staff)

Further characterization of glycine-containing microcystins from the McMurdo Dry Valleys of Antarctica

10 February, 2015
CITATION

Puddick J, Prinsep MR, Wood SA, Cary SC, Hamilton DP, Holland PT 2015. Further characterization of glycine-containing microcystins from the McMurdo Dry Valleys of Antarctica. Toxins, 7: Pages 493-515.

DOI link here

ABSTRACT

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 á´…-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.