1C-O1-1625 PDF
Isolation of novel metabolites from a microbial metabolites fraction library by spectral database search
The new quinomycin derivatives, RK-1355A and B, and new octadepsipeptides, octaminomycin A and B were discovered and isolated from microbial metabolites fraction libraries by extensive spectral database search. Their structures were determined by spectroscopic method based on 1D and 2D NMR and confirmed by MS/MS experiments, especially amino acid sequence of the depsipeptides. RK-1355A and B were the first natural products as a quinoline type quinomycin having a sufoxide. Octaminomycins belong to a cyclic depsipeptide, which forms the ester between the hydroxyl group of threonine and the carboxyl group of proline, containing two leucines, two prolines, valine, phenylalanine, threonine, and N-methyl-tyrosine. The threonine residue was n-propionylated or acetylated at N-terminal.