Chemical Constituents of the Aerial Parts of Santolina chamaecyparissus and Evaluation of Their Antioxidant Activity

Abstract

Santolina chamaecyparissus is an aromatic evergreen herb growing in North Africa and near the Mediterranean coasts of Southern Europe. Literature data focused mainly on the investigation of the essential oil content of the aerial parts of S. chamaecyparissus, but few is known on the chemical composition of its polar extract. Total phenolic content was determined by the Folin-Ciocalteau method and the antioxidant activity of the n-butanol and chloroform fractions of S. chamaecyparissus was tested by Trolox equivalent antioxidant capacity (TEAC) and diphenyl-2-picrylhydrazyl radical (DPPH•) assays. Difference of the phenolic content and of the antioxidant activity between the two extracts prompted us to investigate their chemical composition. Five compounds, eupatilin (1), circimaritin (2), 4’-hydroxy-5,6,7-trimethoxyflavone (3), 1,3-propanediol,2-amino 1-(4-hydroxy-3-methoxyphenyl) (4) and luteolin (5) have been isolated from the chloroform extract, while the investigation of butanolic extract led to the isolation of seven compounds, prunasin (6), luteolin 7- O-β-D-glucopyranoside (7), syringoside (8), junipeionoloside (9), citroside A (10), lonicerin (11) and apigenin 7- O-β-D-neohesperidoside (12). Their structures were elucidated by extensive spectroscopic methods including 1D- (1H, 13C and TOCSY) and 2D-NMR (DQF-COSY, HSQC, HMBC) experiments as well as ESIMS analysis.