A. Jaworski et H. Bruckner, Sequences of polypeptide antibiotics stilboflavins, natural peptaibol libraries of the mold Stilbella flavipes, J PEPT SCI, 7(8), 2001, pp. 433-447
From the culture broths of the mold Stilbella flavipes CBS 146.81, a mixtur
e of polypeptides could be isolated by adsorption on XAD polystyrene resin
and purified by Sephadex LH-20 chromatography. Using preparative thin-layer
chromatography (TLC) three groups of peptides, named stilboflavins (SF) A,
B, and C could be separated. Each of the groups showed microheterogeneity
when investigated by high-performance liquid chromatography (HPLC). Employi
ng on-line HPLC-electrospray ionization tandem mass spectrometry in the pos
itive and negative ionization mode, together with gas chromatography-select
ed ion monitoring mass spectrometry, enantioselective GC and quantitative a
mino acid analysis, the sequences of stilboflavins A and B could be determi
ned. Exchange of Glu in stilboflavins A peptides (acidic) against Gln in st
ilboflavins A peptides (neutral) is the rational for different polarity of
the peptide groups and their separatability by TLC. Since SF A and B are bi
oactive N-acetylated 20-residue peptides with a high proportion of alpha -a
minoisobutyric acid and C-terminal bonded amino alcohols (either leucinol,
isoleucinol or valinol) the peptides belong to the group of peptaibol antib
iotics. Copyright (C) 2001 European Peptide Society and John Wiley & Sons,
Ltd.