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

This article belongs to the Special Issue Marine Drugs Research in Spain[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 (1DCH-RDCs). The absolute configuration of 1b was deduced by ECD/OR/TD-DFT methods and established as 3R,7S,11R.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/2017/001811Xunta de Galicia; ED431E 2018/03German Research Foundation; Gr1211/19–1German Research Foundation; Re1007/9–1Brasil. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); 418729698República de la India. Science and Engineering Research Board; ECR/2017/001811Xunta de Galicia; GRC2018/03