The Challenging Complete and Detailed ¹H and ¹³C NMR Assignment for <i>ent</i>-Kaurenoic Acid, a Remarkable Natural Product.

ABSTRACT: In this work, we report a comprehensive structural assignment of the ¹H and ¹³C nuclear magnetic resonance (NMR) data for kaurenoic acid (KA, ent-kaur-16-en-19-oic acid), a natural diterpene with diverse biological activities. To support this analysis, the methyl ester derivative (ent-methyl-kaur-16-en-19-oate) was also investigated, allowing comparison of chemical shift variations arising from subtle structural differences. The complete assignment was achieved through the analysis of multidimensional NMR spectra and accurate determination of ¹H-¹H coupling constants and signal multiplicities. Experiments including ¹H NMR, ¹³C NMR {¹H}, g-COSY, g-HSQC, g-HMBC, and J-resolved were employed, complement

SUBMITTER: Ferreira AE 

PROVIDER: S-EPMC12771156 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature