Two new Diels–Alder-type adducts from the stem barks of Morus yunanensis

Abstract

Two new Diels–Alder adducts, yunanensins B and D (1 and 2), were isolated from the stem bark of Morus yunanensis. Their structures were determined by spectroscopic analysis. Compounds 1 and 2 showed moderate antioxidant effects on liver microsomal lipid peroxidation induced by Fe²⁺-Cys system, with inhibitory ratios of 57.1% and 67.9% at a concentration of 10^− 5 mol/l.

Keywords::

• Morus yunanensis
• Diels–Alder adducts
• yunanensins B and D
• antioxidant effects

Acknowledgments

This work was financially supported by grants from the National Science and Technology Project of China (Nos 2012ZX09103201-043, 2012ZX09301002-002).