Sesquiterpenes and neolignans from the roots of Illicium dunnianum

Abstract

Two new sesquiterpenes, dunnianoside I (1) and 8′-oxo-6-hydroxy-dihydrophaseic acid methyl ester (2), a new glycoside, dunnianoside J (3), two new neolignans, dunnianeolignans A–B (4, 5), together with 10 known compounds (6–15), were isolated from the roots of Illicium dunnianum. The structures of these new compounds were elucidated by spectroscopic methods including 1D and 2D NMR, HR-ESI-MS, and chemical methods. Compounds 7, 8, and 13–15 exhibited potent antioxidant activities against Fe²⁺-cystine-induced rat liver microsomal lipid peroxidation, with IC₅₀ values ranging from 4.2 ± 0.4 to 38.4 ± 2.6 μM.

Keywords:

• Illicium dunnianum
• Illiciaceae
• sesquiterpene
• neolignan
• glycoside
• antioxidant activities

Acknowledgments

This project was financially supported by the Natural Science Foundation of China (No. 201072234, No. 21132009), and the National Science and Technology Project of China (No. 2012ZX09301002-002). We are grateful to the Department of Instrumental Analysis, Institute of Materia Medica, Chinese Academy of Medical Sciences, and Peking Union Medical College for measuring the IR, UV, NMR, and MS spectra.

Notes

^1. On the occasion of Professor De-Quan Yu's 80th birthday, this special issue is dedicated to him for his huge contributions to natural product chemistry. He and his colleagues have achieved almost a hundred of traditional Chinese medicines or Chinese herbs study and found hundreds of novel compounds, most of which had prominent bioactivities.