Connection of Isolated Stereoclusters by Combining 13C-RCSA, RDC, and J-Based Configurational Analyses and Structural Revision of a Tetraprenyltoluquinol Chromane Meroterpenoid from Sargassum muticum

Juan Carlos C Fuentes-Monteverde; Nilamoni Nath; Abel M Forero; Elena M Balboa; Armando Navarro-Vázquez; Christian Griesinger; Carlos Jiménez; Jaime Rodríguez

doi:10.3390/md20070462

Connection of Isolated Stereoclusters by Combining ¹³C-RCSA, RDC, and J-Based Configurational Analyses and Structural Revision of a Tetraprenyltoluquinol Chromane Meroterpenoid from Sargassum muticum

Mar Drugs. 2022 Jul 18;20(7):462. doi: 10.3390/md20070462.

Authors

Juan Carlos C Fuentes-Monteverde^{1

2}, Nilamoni Nath³, Abel M Forero¹, Elena M Balboa⁴, Armando Navarro-Vázquez⁵, Christian Griesinger², Carlos Jiménez¹, Jaime Rodríguez¹

Affiliations

¹ Departamento de Química e Centro de Investigacións Científicas Avanzadas (CICA), Universidade da Coruña, 15071 A Coruña, Spain.
² NMR Based Structural Biology, MPI for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.
³ Department of Chemistry, Gauhati University, Gopinath Bardoloi Nagar, Guwahati 781014, India.
⁴ Department of Chemical Engineering, Faculty of Science, Campus Ourense, University of Vigo, As Lagoas s/n, 32004 Ourense, Spain.
⁵ Departamento de Química Fundamental, CCEN, Universidade Federal de Pernambuco, Cidade Universitária, Recife 50740-550, Brazil.

Abstract

The seaweed Sargassum muticum, collected on the southern coast of Galicia, yielded a tetraprenyltoluquinol chromane meroditerpene compound known as 1b, whose structure is revised. The relative configuration of 1b was determined by J-based configurational methodology combined with an iJ/DP4 statistical analysis and further confirmed by measuring two anisotropic properties: carbon residual chemical shift anisotropies (¹³C-RCSAs) and one-bond ¹H-¹³C residual dipolar couplings (¹D_CH-RDCs). The absolute configuration of 1b was deduced by ECD/OR/TD-DFT methods and established as 3R,7S,11R.

Keywords: 13C-RCSA; ECD/OR; J-DP4; RDC; Sargassum muticum; coupling constants; meroditerpene.

MeSH terms

Anisotropy
Carbon / chemistry
Sargassum* / chemistry

Substances

Carbon

Grants and funding

This work was funded by grants RTI2018-093634-B-C22 from the State Agency for Research (AEI) of Spain, both co-funded by the European Regional Development Fund (ERDF), BLUEBIOLAB (0474_BLUEBIOLAB_1_E), Programme INTERREG V A of Spain–Portugal (POCTEP) and GRC2018/039 and Agrupación Estratégica CICA-INIBIC ED431E 2018/03 from Xunta de Galicia. This work was also supported by the Max Planck Society and grew out of a collaboration in the context of the Forschergruppe (FOR 934), continued now by the DFG (Gr1211/19–1 and Re1007/9–1)/CAPES 418729698 Project. N.N. gratefully acknowledges the financial support by SERB, New Delhi for ECR Grant with File No.: ECR/2017/001811.