Structure of syringotoxin, a bioactive metabolite of Pseudomonas syringae pv. syringae

[摘要]

The covalent structure of syringotoxin, a bioactive metabolite of Pseudomonas syringae pv. syringae isolates, pathogenic on various species of citrus trees, has been deduced from ID and 2D ¹H- and ¹³C-NMR spectra combined with extensive FAB-MS data and results of some chemical reactions. Similarly to syringomicins and syringostatins, produced by other plant pathogenic strains of P. syringae pv. syringae, syringotoxin is a lipodep-sinonapeptide. Its peptide moiety corresponds to Ser-Dab-Gly-Hse-Om-aThr-Dhb-(3-OH)Asp-(4-Cl)Thr with the terminal carboxy group closing a macrocyclic ring on the OH group of the N-terminal Ser, which in turn is N-acetylated by 3-hydroxytetradecanoic acid.

[学科分类] 生物化学/生物物理

[关键词] Phytotoxin;Lipodepsipeptide;Syringotoxin;Pseudomonas syringae pv. syringae;DMSO;dimethyl sulf oxide;FAB-MS;fast atom bombardment mass spectrometry;TBDMS;t-butyldimethylsilyl;(3-OH)Asp;3-hydroxyaspartic acid;Dab;2;4-diaminobutyric acid;Dhb;2;3-dehydro-2-aminobutyric acid;(4-Cl)Thr;4-chlorothreonine;Hse;homoserine;Hse>;homoserine lactone;(4-OH)Thr;4-hydroxythreonine;aThr;allo-threonine;DQF-COSY;double quantum filtered correlated spectroscopy;TOCSY;total correlated spectroscopy;NOESY;nuclear Overhauser effect correlated spectroscopy;SR;syringomyein;ST;syringotoxin