Proposal for structural revision of several disubstituted tricycloalternarenes

Mono- and di-substituted tricycloalternarenes form a group of meroterpenes isolated from epiphytic fungi. In this work, we have made thirteen proposals to correct erroneous structures of disubstituted tricycloalternarenes, also known as guignardones. Thus, in this group of compounds, structures of g...

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Detalles Bibliográficos
Autores: Fraga, Braulio M., Díaz, Carmen E.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/304206
Acceso en línea:http://hdl.handle.net/10261/304206
Access Level:acceso abierto
Palabra clave:Ascomycetes
Epiphytic fungi
Disubstituted tricycloalternarenes
Guignardones
Structural revisions
Descripción
Sumario:Mono- and di-substituted tricycloalternarenes form a group of meroterpenes isolated from epiphytic fungi. In this work, we have made thirteen proposals to correct erroneous structures of disubstituted tricycloalternarenes, also known as guignardones. Thus, in this group of compounds, structures of guignardones K, L3, M, W, tricycloalternarene B2, 15-hydroxy-tricycloalternarene 5 b, guignardiaene D, magnardones F–H and coibanols A-C, have been revised. Moreover, we have also explained why there are only two types of disubstituted tricycloalternarenes in nature, one with a –CH2-O- β-bridge between C-6 and C-4 (6R,4S-configuration), and the other with a –CH2-O- α-bridge between C-4 and C-6 (4R,6S-configuration). Finally, the relative and absolute configurations of phyllostictone A and the absolute structure of phyllostictone D have been established by comparison with those of magnardones I and D, respectively.