Incorporation of 4J-HMBC and NOE Data into Computer-Assisted Structure Elucidation with WebCocon

Matthias Köck; Thomas Lindel; Jochen Junker

doi:10.3390/molecules26164846

Incorporation of ⁴J-HMBC and NOE Data into Computer-Assisted Structure Elucidation with WebCocon

Molecules. 2021 Aug 11;26(16):4846. doi: 10.3390/molecules26164846.

Authors

Matthias Köck¹, Thomas Lindel², Jochen Junker³

Affiliations

¹ Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, 27570 Bremerhaven, Germany.
² Institute of Organic Chemistry, Technical University of Braunschweig, 38106 Braunschweig, Germany.
³ Oswaldo Cruz Foundation-CDTS, Rio de Janeiro 21040-900, Brazil.

Abstract

Over the past decades, different software programs have been developed for the Computer-Assisted Structure Elucidation (CASE) with NMR data using with various approaches. WebCocon is one of them that has been continuously improved over the past 20 years. Here, we present the inclusion of 4J_CH correlations (4J-HMBC) in the HMBC interpretation of Cocon and NOE data in WebCocon. The 4J-HMBC data is used during the structure generation process, while the NOE data is used in post-processing of the results. The marine natural product oxocyclostylidol was selected to demonstrate WebCocon's enhanced HMBC data processing capabilities. A systematic study of the 4J_CH correlations of oxocyclostylidol was performed. The application of NOEs in CASE is demonstrated using the NOE correlations of the diterpene pyrone asperginol A known from the literature. As a result, we obtained a conformation that corresponds very well to the existing X-ray structure.

Keywords: CASE; HMBC; NMR; NOE; structure elucidation; web-based tools.