1. Stereochemical heterogeneity in Verongid sponge metabolites. Absolute stereochemistry of (+)-fistularin-3 and (+)-11-epi-fistularin-3 by microscale LCMS-Marfey's analysis.
- Author
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Rogers EW, de Oliveira MF, Berlinck RG, König GM, and Molinski TF
- Subjects
- Animals, Australia, Brazil, Dinitrobenzenes, Florida, Isoxazoles analysis, Mixed Function Oxygenases metabolism, Molecular Structure, Porifera enzymology, Porifera metabolism, Stereoisomerism, Tyrosine analysis, Alanine analogs & derivatives, Isoxazoles chemistry, Porifera chemistry, Tyrosine analogs & derivatives, Tyrosine chemistry
- Abstract
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.
- Published
- 2005
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