Seven new microcystins possessing two L-glutamic acid units, isolated from Anabaena sp. strain 186

Chem Res Toxicol. 1998 Feb;11(2):143-9. doi: 10.1021/tx970120t.

Abstract

Electrospray ionization mass spectrometry has been applied to the structure assignment of seven new microcystins (1-7), obtained from cultured Anabaena sp. strain 186. The seven new microcystins contain the dehydroalanine (Dha) or L-Ser unit instead of the N-methyldehydroalanine unit and the L-Glu and/or its delta-methyl ester [E(OMe)] units at the two variable L-amino acid units, and the structures were assigned as [Dha7]microcystin-E(OMe)E(OMe) (1), [D-Asp3,Dha7]microcystin-E(OMe)E(OMe) (2), [L-Ser7]microcystin-E(OMe)E(OMe) (3), [D-Asp3,L-Ser7]microcystin-E(OMe)E(OMe) (4), [Dha7]microcystin-EE(OMe) (5), [D-Asp3,Dha7]microcystin-EE(OMe) (6), and [L-Ser7]microcystin-EE(OMe) (7). These microcystins are the first examples containing dicarboxylic amino acids at the two variable L-amino acid units in microcystins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Anabaena / chemistry*
  • Bacterial Toxins / analysis
  • Bacterial Toxins / isolation & purification*
  • Glutamic Acid / analysis
  • Glutamic Acid / chemistry*
  • Mass Spectrometry
  • Peptides, Cyclic / analysis
  • Peptides, Cyclic / isolation & purification*

Substances

  • Bacterial Toxins
  • Peptides, Cyclic
  • Glutamic Acid