Peyssonnosides A-B, Unusual Diterpene Glycosides with a Sterically Encumbered Cyclopropane Motif: Structure Elucidation Using an Integrated Spectroscopic and Computational Workflow
| Autor: | Katy M. Soapi, Prasad L. Polavarapu, Serge Lavoie, Bhuwan K. Chhetri, Nazia Mojib, Kerstin Gagaring, Julia Kubanek, Vijay V. Raghavan, Cassandra L. Quave, Case W. McNamara, Brandon Dale, Anne Marie Sweeney-Jones |
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| Rok vydání: | 2019 |
| Předmět: |
chemistry.chemical_classification
Models Molecular Aquatic Organisms Molecular Structure 010405 organic chemistry Stereochemistry Spectrum Analysis Organic Chemistry Absolute configuration Glycoside Nuclear Overhauser effect 010402 general chemistry 01 natural sciences 0104 chemical sciences Cyclopropane chemistry.chemical_compound chemistry Rhodophyta Moiety Glycosides Diterpene Diterpenes Optical rotatory dispersion Two-dimensional nuclear magnetic resonance spectroscopy |
| Zdroj: | The Journal of organic chemistry. 84(13) |
| ISSN: | 1520-6904 |
| Popis: | [Image: see text] Two sulfated diterpene glycosides featuring a highly substituted and sterically encumbered cyclopropane ring have been isolated from the marine red alga Peyssonnelia sp. Combination of a wide array of 2D NMR spectroscopic experiments, in a systematic structure elucidation workflow, revealed that peyssonnosides A–B (1–2) represent a new class of diterpene glycosides with a tetracyclo [7.5.0.0(1,10).0(5,9)] tetradecane architecture. A salient feature of this workflow is the unique application of quantitative interproton distances obtained from the rotating frame Overhauser effect spectroscopy (ROESY) NMR experiment, wherein the β-d-glucose moiety of 1 was used as an internal probe to unequivocally determine the absolute configuration, which was also supported by optical rotatory dispersion (ORD). Peyssonnoside A (1) exhibited promising activity against liver stage Plasmodium berghei and moderate antimethicillin-resistant Staphylococcus aureus (MRSA) activity, with no cytotoxicity against human keratinocytes. Additionally, 1 showed strong growth inhibition of the marine fungus Dendryphiella salina indicating an antifungal ecological role in its natural environment. The high natural abundance and novel carbon skeleton of 1 suggests a rare terpene cyclase machinery, exemplifying the chemical diversity in this phylogenetically distinct marine red alga. |
| Databáze: | OpenAIRE |
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