NMR assignments and X-ray diffraction spectra for two unusual kaurene diterpenes from Erythroxylum barbatum

Claudio Costa dos Santos; Mary Anne Sousa Lima; Raimundo Braz-Filho; Carlos Alberto de Simone; Edilberto Rocha Silveira

doi:10.1002/mrc.1700

NMR assignments and X-ray diffraction spectra for two unusual kaurene diterpenes from Erythroxylum barbatum

Magn Reson Chem. 2005 Dec;43(12):1012-5. doi: 10.1002/mrc.1700.

Authors

Claudio Costa dos Santos¹, Mary Anne Sousa Lima, Raimundo Braz-Filho, Carlos Alberto de Simone, Edilberto Rocha Silveira

Affiliation

¹ Curso de Pós-Graduação em Química Orgânica, Departamento de Química Orgânica e Inorgânica, Centro de Ciências, Universidade Federal do Ceará, CP 12 200, Fortaleza-CE, 60451-970, Brazil.

PMID: 16142836
DOI: 10.1002/mrc.1700

Abstract

The structural characterization of two new, unusual kaurene diterpenes isolated from roots of Erythroxylum barbatum is described. 1D NMR and several 2D shift-correlated NMR pulse sequences (1H,1H-COSY, HMQC, HMBC and NOESY) were used for structure elucidation and the unambiguous 1H and 13C chemical shifts assignments. Single crystal X-ray diffraction analysis was also used to confirm the final relative configuration of the compounds possessing the C-20 methyl and the CH2-15 methylene groups in cis-orientation.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Diterpenes, Kaurane / chemistry*
Erythroxylaceae / chemistry*
Magnetic Resonance Spectroscopy
Molecular Conformation
X-Ray Diffraction

Substances

Diterpenes, Kaurane
kaurene