Noralashinol B, a norlignan with cytotoxicity from stem barks of Syringa pinnatifolia

Abstract

One new norlignan, noralashinol B (1), and one new natural product, proposed noralashinol C (2), were isolated in a continuous phytochemical investigation on the stem barks of Syringa pinnatifolia. Their structures were elucidated based on the analysis of spectroscopic data, including mass spectrometry and 1D and 2D NMR spectroscopies, and the absolute configuration was determined by experimental and calculated electronic circular dichroism. Compound 1 showed a weak cytotoxicity against HepG2 hepatic cancer cells with its IC₅₀ value of 31.7 μM. Furthermore, 1 induced apoptosis of HepG2 cells in a dose-dependent manner at concentrations of 0–80.0 μM.

Keywords:

• Syringa pinnatifolia
• norlignan
• noralashinol B
• noralashinol C
• calculated ECD
• cytotoxicity

Acknowledgments

The authors expressed their thanks to Prof. Chen-Su-Yi-Le (Alxa League Mongolian Hospital) for his help in collection of plant material and authentication, and also thank Dr. Li Li (Chinese Academy of Medical Sciences & Peking Union Medical College) for her assistance on ECD calculation.