New neuroprotective dibenzylbutane lignans isolated from Machilus thunbergii

Abstract

Two new dibenzylbutane lignans, namely rel-methyl (2S)-2-hydroxy-2-2′-((2″R,3″R)-4″-guaiacyl-2″,3″dimethylbutyl)-5′-oxo-2′,5′-dihydro-2-furanylethnoate (1) and rel-methyl (2S)-2-hydroxy-2-2′-((2″R,3″S)-4″-guaiacyl-2″,3″dimethylbutyl)-5′-oxo-2′,5′-dihydro-2-furanylethnoate (2), were isolated from the bark of Machilus thunbergii. Their structures were elucidated by spectral analysis. These two lignans exerted significant neuroprotective activities against glutamate-induced neurotoxicity in primary cultures of rat cortical cells. Compounds 1 and 2 represent a new type of lignan skeleton that has not been reported so far from nature.

Keywords:

• Machilus thunbergii
• rel-methyl (2S)-2-hydroxy-2-2′-((2″R,3″R)-4″-guaiacyl-2″,3″dimethylbutyl)-5′-oxo-2′,5′-dihydro-2-furanylethnoate
• rel-methyl (2S)-2-hydroxy-2-2′-((2″R,3″S)-4″-guaiacyl-2″,3″dimethylbutyl)-5′-oxo-2′,5′-dihydro-2-furanylethnoate
• neuroprotective
• lignans

Acknowledgements

This work was supported by the second phase of the Brain Korea 21 Programme in 2009 and the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund) (KRF-2008-331-E00452).