Argutalactone, an unprecedented sesquiterpenoid lactone with a 6/5/7 tricyclic system from Incarvillea arguta

Abstract

Argutalactone (1), a novel sesquiterpenoid lactone featuring an unprecedented 6/5/7 rigid skeleton, was isolated from the roots of Incarvillea arguta. The structure and relative configuration of 1 were established by extensive analysis of spectroscopic data. The absolute configuration of 1 was determined as 2R,5S,10R,12S based on the analysis of biogenetical transformation, comparison of the optical rotation with literature data, and comparison of the experimental circular dichroism spectrum with the calculated electronic circular dichroism spectra.

Keywords:

• Incarvillea arguta
• argutalactone
• sesquiterpenoid lactone
• density functional calculations

Acknowledgments

The authors thank Prof. Yue-Kui Wang of Shanxi University for his helpful discussions and suggestions. This work was financially supported by program NCET Foundation, NSFC (30725045 and 20803022), the National Science & Technology Major Project ‘Key New Drug Creation and Manufacturing Program’, China (2009ZX09311-001, 2008ZX09101-Z-029, 2009ZX0910 3-375, and 2009ZX09501-001).

Notes

1. These authors contributed equally to this work.

Additional information

Notes on contributors

Jian-Jun Fu

1

Li-Yan Wang

1