Stereochemical heterogeneity in Verongid sponge metabolites. Absolute stereochemistry of (+)-fistularin-3 and (+)-11-epi-fistularin-3 by microscale LCMS-Marfey's analysis.
The absolute configurations of fistularin-3, 11-epi-fistularin-3, and a related bis-oxazolidinone were determined by microscale hydrolysis followed by derivatization with 1-fluoro-2,4-dinitrophenyl-5-l-alaninamide. Samples of fistularin-3 from Verongid marine sponges collected in the Great Barrier Reef (Australia), Baía de Todos os Santos (Brazil), and the Key Largo, Florida (USA) varied in configuration at C11, a phenomenon that may be attributed to the involvement of stereochemically promiscuous hydroxylase enzymes. Variability in C11 configuration in fistularin-3 samples may have been overlooked in previously reported encounters due to the similarity of spectroscopic properties of fistularin-3 and 11-epi-fistularin-3 and their coelution under chromatographic conditions. Stereochemical heterogeneity at C11 in fistularin-3 samples suggests a possibility of a native biotransformation of suitable precursor in Verongid sponges by their associated microbial flora.
Rogers
Evan W
EW
Department of Chemistry, University of California, Davis, 95616, USA.
de Oliveira
Maria Fernanda
MF
Berlinck
Roberto G S
RG
König
Gabriele M
GM
Molinski
Tadeusz F
TF
D000409:Alanine / Q000031:analogs & derivatives*; D000818:Animals; D001315:Australia; D001938:Brazil; D004136:Dinitrobenzenes; D005431:Florida; D007555:Isoxazoles / Q000032:analysis / Q000737:chemistry*; D006899:Mixed Function Oxygenases / Q000378:metabolism; D015394:Molecular Structure; D011161:Porifera / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism; D013237:Stereoisomerism; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry*
D004136:Dinitrobenzenes; D007555:Isoxazoles; D014443:Tyrosine; C076216:fistularin 3; C047134:Marfey's reagent; D006899:Mixed Function Oxygenases; D000409:Alanine