Etude phytochimique et activité antioxydante de la plante Centaurea melitensis L.

Abstract

In this work we have been interested by secondary metabolites of the Asteraceae family. Our interest has been on the sesquiterpene lactones and flavonoids descended from the genus Centaurea. Thus a deep biographic study has established a collection of familiar and new structures of these molecules. This study from 2005 until the end of 2012 showed that 51 species have been investigated. These works mention 174 structures variously varied for both of these metabolites, with a predominance noticed for the sesquiterpene skeleton which the majorities are guainolides. Our phytochemical and biological experimentation on the Algerian species Centaurea melitensis L. has on one hand highlight the isolation of fourteen (14) molecules (only eleven (11) have been identified): Three germacranolides in the pure state, a mixture of two elemanolides, another mixture of two elemanes, three flavonoid aglycones and a phenolic acid. On the other hand the working up of the antioxidant of the methanolic extract of our plant. The determination of structures has been realised by combining the results of spectrometric and spectroscopic methods ﴾EIMS, UV, NMR-1D, 2-D﴿.