Chiroptical study and absolute configuration of securinine oxidation products

Abstract

Time-dependant density functional theory–electronic circular dichroism spectra prediction was carried out to study the absolute configuration of phyllanthidine-type derivatives 5 and 6, derived from securinine (1) and its enantiomer virosecurinine (2), respectively. This method demonstrated to be very reliable in this alkaloid series. Thus, 5 and 6 shared the same stereochemistry as their parent precursors, confirming the retentive nature of the oxidation sequence. In addition, this study highlighted the key role of the methylene bridge (BC ring) in the chiroptical activity of these compounds. These results fully clarified the stereochemical relationships between the phyllanthidine and the securinine subgroups.

Keywords::

• securinine
• phyllanthidine
• TDDFT-ECD
• X-ray crystallography
• absolute configuration

Acknowledgements

We express our deeply thanks to Dr Christophe Velours (ICSN Gif/Yvette) and Dr Serge Bouaziz (CNRS/Paris Descartes University) for their technical assistance (ECD measurement). We also thank Pr Yiming Li (Shanghai University of TCM, China) for the generous gift of allosecurinine. This work was granted access to the HPC resources of IDRIS under the allocation 2014-100483 OUMOLPO made by GENCI.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

We gratefully acknowledged the financial support from Paris Descartes University and CNRS.