A Pair Of New Lignan Enantiomers From Croton Tiglium

A pair of new 3',7-epoxy-8,4'-oxyneolignan enantiomers [(+)-1 and (-)-1] as well as a known phenylpropanoid (2) were isolated from the seeds of Croton tiglium Linn. Their structures were established based on extensive spectroscopic analyses. The absolute configurations of (+)-1 and (-)-1 were determined by NMR data calcula-tions and electronic circular dichroism calculations. All compounds were isolated from the genus Croton for the first time. Particularly, (+)-1 and (-)-1 were the first 3',7-epoxy-8,4'-oxyneolignanes reported in Croton. The chemotaxonomic significance of these compounds was discussed.