Lipid metabolites with free-radical scavenging activity from Euphorbia helioscopia L.

Abstract The methanolic extract of the plant Euphorbia helioscopia L. exhibited an interesting free-radical scavenging activity. From the aerial parts of Euphorbia helioscopia L. (Euphorbiaceae), a complex mixture of seven cerebrosides together with glucoclionasterol, a digalactosyldiacylglycerol and a diacylmonogalactosylglycerol were identified. The structures of the cerebrosides were characterized as 1- O -β- d -glucosides of phytosphingosines, which comprised (2 S , 3 S , 4 E , 8 E )-2-amino-4( E ),8( E )-octadecadiene-1,3-diol, (2 S , 3 S , 4 E , 8 Z )-2-amino-4( E ),8( Z )-octadecadiene-1,3-diol, (2 S , 3 S , 4 R , 8 Z )-2-amino-8( Z )-octadecene-1,3,4-triol as long chain bases with seven 2-hydroxy fatty acids of varying chain lengths (C 16 , C 24:1 , C 26:1 , C 24 , C 26 , C 28:1 ) linked to the amino group. The glycosylglycerides were characterized as (2 S )-2,3- O -di-(9,12,15-octadecatrienoyl)-glyceryl-6- O -( α - d -galactopyranosyl)-β- d -galactopyranoside and (2 S )-2,3- O -di-(9,12,15-octadecatrienoyl)-glyceryl-1- O -β- d -galactopyranoside. The structures were established on the basis of spectroscopic data and chemical reactions.