Isolation and structrual identification of oleuropein in leaves of ascolano olive introduced from Greece.

There are many antioxidants in olive leaves such as oleuropein,flavonoids and polyphenols. Leaves of Ascolano olive introduced from Greece were successively extracted with EtOH-H2 O(60 ∶ 40),petroleum ether and ethyl acetate. The ethyl acetate fraction was subjected to silica gel column chromatography,then treated with preparative HPLC to obtain a compound with content of 95 %,which was identificated to be oleuropein by UV,IR,MS and NMR. Oleuropein could be acidically hydrolyzed to give hydroxytyrosol and elenolic acid as main products.