NMR confirmation that tryptophan dehydrogenation occurs with syn stereochemistry during the biosynthesis of CDA in Streptomyces coelicolor.
Doubly labeled (2'S,3'R)-[3'-2H1,13C1]-tryptophan was fed to the Trp-His auxotrophic Streptomyces coelicolor strain WH101. Mass spectrometry showed single and double incorporation of the labeled Trp into the calcium-dependent lipopeptide antibiotic (CDA4a). From 13C NMR spectroscopy, it was apparent that the C3'-signal of the (Z)-2',3'-dehydrotryptophan (position 11 in CDA4) was a 1:1:1 triplet indicating that the deuterium atom in the pro-R position of the methylene group is retained during Trp-oxidation. This provides definitive proof that Trp dehydrogenation occurs through the loss of the 2' and pro-3'S hydrogen atoms with overall syn stereochemistry.
Amir-Heidari
Bagher
B
School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester, UK.
Micklefield
Jason
J
D006865:Hydrogenation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D012015:Reference Standards; D013237:Stereoisomerism; D048372:Streptomyces coelicolor / Q000737:chemistry / Q000378:metabolism*; D014364:Tryptophan / Q000138:chemical synthesis / Q000737:chemistry*
C040487:CDA antibiotic; D010455:Peptides; D014364:Tryptophan