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[PMID]: | 28901768 |
[Au] Autor: | Mazzeo G; Cimmino A; Masi M; Longhi G; Maddau L; Memo M; Evidente A; Abbate S |
[Ad] Endereço: | Dipartimento di Medicina Molecolare e Traslazionale, Università degli Studi di Brescia , Viale Europa 11, 25123 Brescia, Italy. |
[Ti] Título: | Importance and Difficulties in the Use of Chiroptical Methods to Assign the Absolute Configuration of Natural Products: The Case of Phytotoxic Pyrones and Furanones Produced by Diplodia corticola. |
[So] Source: | J Nat Prod;80(9):2406-2415, 2017 Sep 22. | [Is] ISSN: | 1520-6025 |
[Cp] País de publicação: | United States |
[La] Idioma: | eng |
[Ab] Resumo: | α-Pyrones and furanones are metabolites produced by Diplodia corticola, a pathogen of cork oak. Previously, the absolute configuration (AC) of diplopyrone was defined by chiroptical methods and Mosher's method. Using X-ray and chiroptical methods, the AC of sapinofuranone C was assigned, while that of the (4S,5S)-enantiomer of sapinofuranone B was established by enantioselective total synthesis. Diplofuranone A and diplobifuranylones A-C ACs are still unassigned. Here electronic and vibrational circular dichroism (ECD and VCD) and optical rotatory dispersion (ORD) spectra are reported and compared with density functional theory computations. The AC of the (4S,5S)-enantiomer of sapinofuranone B and sapinofuranone C is checked for completeness. The AC of diplobifuranylones A-C is assigned as (2S,2'S,5'S,6'S), (2S,2'R,5'S,6'R), and (2S,2'S,5'R,6'R), respectively, with the Mosher's method applied to define the absolute configuration of the carbinol stereogenic carbon. The AC assignment of sapinofuranones is problematic: while diplofuranone A is (4S,9R), sapinofuranones B and C are (4S,5S) according to ORD and VCD, but not to ECD. To eliminate these ambiguities, ECD and VCD spectra of a di-p-bromobenzoate derivative of sapinofuranone C are measured and calculated. For phytotoxicity studies, it is relevant that all six compounds share the S configuration for the stereogenic carbon atom of the lactone moiety. |
[Mh] Termos MeSH primário: |
Alcenos/química Produtos Biológicos/química Furanos/química Lactonas/química Pironas/química Quercus/química
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[Mh] Termos MeSH secundário: |
Alcenos/toxicidade Ascomicetos Dicroísmo Circular Furanos/toxicidade Lactonas/toxicidade Estrutura Molecular Dispersão Óptica Rotatória Pironas/toxicidade Estereoisomerismo
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[Pt] Tipo de publicação: | JOURNAL ARTICLE |
[Nm] Nome de substância:
| 0 (Alkenes); 0 (Biological Products); 0 (Furans); 0 (Lactones); 0 (Pyrones); 0 (diplobifuranylone A); 0 (diplobifuranylone B); 0 (diplopyrone); 0 (sapinofuranone B) |
[Em] Mês de entrada: | 1710 |
[Cu] Atualização por classe: | 171031 |
[Lr] Data última revisão:
| 171031 |
[Sb] Subgrupo de revista: | IM |
[Da] Data de entrada para processamento: | 170914 |
[St] Status: | MEDLINE |
[do] DOI: | 10.1021/acs.jnatprod.7b00119 |
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