Enantiomeric lignans with antineuroinflammatory activities from Mappianthus iodoides

Abstract

• Three new pairs of lignan enantiomers were isolated from Mappianthus iodoides. • Their structures were elucidated by spectroscopic analyses, X-ray diffraction, and ECD spectra. • Five compounds could moderately inhibit NO production in LPS-induced BV-2 microglial cells. Three new pairs of lignan enantiomers ( 1a / 1b ‒ 3a / 3b ) and two pairs of known lignan enantiomers ( 4a / 4b and 5a / 5b ) were isolated from the stems of Mappianthus iodoides. The structures of the enantiomers were elucidated by comprehensive spectroscopic analyses. Their absolute configurations were assigned by single-crystal X-ray diffraction analysis as well as comparison of the experimental and calculated ECD spectra. The antineuroinflammatory activity research revealed that compounds 2a , 2b , 3a , 4a , and 5b could moderately inhibit NO production in LPS-induced BV-2 microglial cells with IC 50 values ranging from 13.42 to 48.34 μ M.