Isolation and identification of N-mercapto-4-formylcarbostyril, an antibiotic produced by Pseudomonas fluorescens.
Fakhouri, Walid; Walker, Frank; Vogler, Bernhard; Armbruster, Wolfgang; Buchenauer, Heinrich.
Phytochemistry (2001), 58(8), 1297-1303.

Abstract

Pseudomonas fluorescens strain G308 isolated from barley leaves produces a novel antibiotic substance that was purified by preparative TLC and HPLC and identified as N-mercapto-4-formylcarbostyril (Cbs) by LC/DAD, IR, LC-ES+/MS, LC-ES-/MS, GC-EI/MS, LC-HRES+/MS, mass isotope ratios anal., 1H NMR and 13C NMR anal. The purified new antibiotic compd. is effective against many phytopathogenic fungi in vitro. The compd. inhibited at 25 ppm spore germination and germ tube growth of the following fungi; Fusarium oxysporum f. sp. lycopersici, Fusarium culmorum, Cladosporium cucumerinum and Colletotrichum lagenarium. At concns. up to 125 ppm, the compd. did not interfere with release of zoospores from sporangia and germination of encysted zoospores of Phytophthora infestans.