Novel bioactive lipodepsipeptides from Pseudomonas syringae: The pseudomycins

• Published in: FEBS letters 1994-11, Vol.355 (1), p.96-100
• Main Authors: Ballio, A., Bossa, F., Di Giorgio, D., Ferranti, P., Paci, M., Pucci, P., Scaloni, A., Segre, A., Strobel, G.A.
• Format: Article
• Language: English
• Subjects: 2D NMR, two-dimensional nuclear magnetic resonance; a Thr, allothreonine; Amino Acid Sequence; Amino Acids - analysis; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Asp-(3OH), 3-hydroxyaspartic acid; Bacterial Proteins - chemistry; Bacterial Proteins - pharmacology; Chromatography, High Pressure Liquid; Dab, 2,4-diaminobutyric acid; Dhb, dehydro-2-aminobutyric acid; FAB-MS, fast atom bombardment mass spectrometry; Fatty Acids - analysis; FID, free induction decay; Lipodepsipeptide; Magnetic Resonance Spectroscopy; Molecular Sequence Data; NOE, nuclear Overhauser effect; NOESY, nuclear Overhauser effect correlated spectroscopy; Peptides - chemistry; Peptides - pharmacology; Phytotoxin; Plants - drug effects; Plants - metabolism; Pseudomonas - chemistry; Pseudomonas syringae; Pseudomycin; Syringomycin; TBDMS, t-butyldimethylsilyl; TFA, trifluoroacetic acid; Thr(4-Cl), 4-chlorothreonine; TOCSY, total correlated spectroscopy; TPPI, time proportional phase increment
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/0014-5793(94)01179-6

The covalent structure and most of the stereochemistry of the pseudomycins, bioactive metabolites of a transposon-generated mutant of a Pseudomonas syringae wild-type strain proposed for the biological control of Dutch elm disease, have been determined. While two pseudomycins are identical to the known syringopeptins 25-A and 25-B, pseudomycins A, B, C, C′ are new lipodepsinonapeptides. For all of these the peptide moiety corresponds to l-Ser- d-Dab- l-Asp- l-Lys- l-Dab- l-aThr-Z-Dhb- l-Asp(3-OH) - l-Thr(4-Cl) with the terminal carboxyl group closing a macrocyclic ring on the OH group of the N-terminal Ser. This is in turn N-acylated by 3,4-dihydroxytetradecanoate in pseudomycin A, by 3-hydroxytetradecanoate in pseudomycin B, by 3,4-dihydroxyhexadecanoate in pseudomycin C, and by 3-hydroxyhexadecanoate in pseudomycin C′. Some preliminary data on the biological activity of pseudomycin A are reported.