Seven novel macrocyclic polypeptides from Viola arvensis

J Nat Prod. 1999 Feb;62(2):283-6. doi: 10.1021/np9803878.

Abstract

Seven novel macrocyclic polypeptides, designated as varv peptides B-H, have been isolated from the aerial parts of Viola arvensis. Their primary structures have been elucidated by automated Edman degradation and mass spectrometry. They all consist of 29 or 30 amino acid residues, covalently cyclized via the amide backbone and by three internal disulfide bridges. Their amino acid sequences are as follows: varv peptide B, cyclo-(TCFGGTCNTPGCSCDPWPMCSRNGLPVCGE); varv peptide C, cyclo-(TCVGGTCNTPGCSCSWPVCTRNGVPICGE); varv peptide D, cyclo-(TCVGGSCNTPGCSCSWPVCTRNGLPICGE); varv peptide E, cyclo-(TCVGGTCNTPGCSCSWPVCTRNGLPICGE); varv peptide F, cyclo-(TCTLGTCYTAGCSCSWPVCTRNGVPICGE); varv peptide G, cyclo-(TCFGGTCNTPGCSCDPWPVCSRNGVPVCGE); and varv peptide H, cyclo-(TCFGGTCNTPGCSCETWPVCSRNGLPVCGE). The varv peptides B-H exhibited high degrees of homology with the hitherto known macrocyclic peptides varv peptide A, kalata B1, violapeptide I, circulins A and B, and cyclopsychotride A.

MeSH terms

  • Amino Acid Sequence
  • Molecular Sequence Data
  • Peptides, Cyclic / chemistry
  • Peptides, Cyclic / genetics
  • Peptides, Cyclic / isolation & purification*
  • Phylogeny
  • Plants / chemistry*
  • Protein Conformation
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Substances

  • Peptides, Cyclic