ORIGIN AND IDENTIFICATION OF THE POLYPHENOLS OF CORK OAK ACORNS ATTACKED BY CARPOPHAGOUS INSECTS

Abstract

The Algerian cork oak forest is constituted with numerous essences, essentially the cork oak (Quercus suber) which establishes an ecosystem very rich in terms of biovariety. The called acorn ballot characteristic fruit of the genus Quercus forms in the year, its shape and its size vary according to trees. This reproductive organ is constituted with an embryo surrounded with a tissue containing materials of reserves (the albumen) and protected by a more or less thick and impervious integument. The acorn is classified in the category of girdles kick out which is the object of numerous attacks of insects. We extracted acorns of cork oak infested by carpophagous insects using organic solvents as the acetone, the chloroform, the ethanol and also extract by water. The dosage of the total polyphenols realized by Folin-Ciacolteau's method allowed to show that phenolic composition is important for all the used solvents, it is the ethanol which extracts most of polyphenols (154,8 mg GAE/g dry weight), it seems clear that among the used solvents, the chloroform is the least effective solvent (44,6 mg GAE/g dry weight). Dosage, quantification and identification of the polyphenolic contents was realized by coupling chromatography in gas phase/spectrometry of mass (GC/MS). Chromatographic profile and spectre show that the compound adults are going molecules from 18 to 29 carbons. We identified besides polyphenols with 28 and 29 carbons, acids, alcohols and aldehyds.