Complete 1H and 13C NMR Assignment of the ent-Labdane 2α-Hydroxyeperuic Acid Combining Conventional NMR Methods and HiFSA.

Abstract

The complete assignment of ¹H and ¹³C spectra of the ent-labdane 2α-hydroxyeperuic acid (3) has been achieved through spin simulation constructed with experimental data obtained from conventional NMR experiments such as ¹H, ¹³C, HSQC, HMBC, COSY, NOESY, 1D-TOCSY, and J-resolved (Jres) and data obtained from ¹H iterative full-spin analysis (HiFSA) in the prerelease version of Cosmic Truth (CT), a web-based software for spectral analysis. The combination of experimental and theoretical data is helpful in the complete NMR assignment of molecules where signal overlapping is complicated, as in most natural products.