Study Of Effective Component Of Antioxidant In Olive Leaves And The Content Changes

There are many antioxidants in olive leaves such as oleuropein flavonoids andpolyphenols. The method of preparing oleuropein monomer was established,and its chemicalstructure was confirmed by spectral analysis.The analytic methods of oleuropein, flavonoidsand polyphenols were established and variation of the contents were studied. The extractionand the purification technologies were studied.The better extract technologies were studied byorthogonal experiment and the resins were used to purified the extract of olive leaves.Olive leaves were extracted with EtOH-H₂O(60:40) and then extracted by petroleum etherand ethyl acetate.The ethyl acetate fraction was subjected to silica gel columnchromatography, and treated with preparation HPLC,then a product with content of 95%oleuropein was got.It was confirmed to be oleuropein by UV IR MS and NMR.The identification of oleuropein was carried out by HPLC.The column was ODS (φ4.6mm×150mm, 5μm);the mobile phase was 45% MeOH and 55% water with 0.2% aceticacid.Quantification of oleuropein was carried out at 230 nm. The flow rate was 1mL/min. Thecontents of oleuropein in olive leaves of different breeds were studied.The Keladi olive leaveshad the highest oleuropein content.The Peiduoling olive leaves had the lowest oleuropeincontent.The content of oleuropein in the 9 breeds distributed in three areas, aboutl 7%,11% and7%. The contents of oleuropein in breeds of ascolano,leccino,picholine olive leaves collectedin different months were studied. The contents of oleuropein were determined by HPLC. TheAgcolano olive leaves had the highest oleuropein content, then the Picholine,and the Leccinoolive leaves had the least. The higher contents of oleuropein was in February and May. Thelower contents of oleuropein was in November and April.The change of flavonoids and polyphenols contents in olive leaves collected in differentmonths was studied by colorimetry. The higher contents of flavonoids were from December tonext March. The lower contents of flavonoids were in October and April.The the highestflavonoids content was in February of the Ascolano(12.54%),the lowest was in October of theLeccino(2.01%).The highest polyphenol content was in March of the Ascolano(9.72%),thelowest was in October of the Leccino,only 2.53%.The best extraction technology was studied.It was extracted with 80 % EtOH-H₂O for 3times,each time for 3.5 h.The proportion of olive leaves and solvent dosage was 1:10 and thetemperature was 70℃.The best purification technology by resin was studied.The AB-8 resinwas better than other resins.The quantity of saturated adsorption of AB-8 was 32.1mg per 1g wet resin.The best condition was studied.70% EtOH-H₂O was used to elute oleuropein and theconcentration of the sample was 2 mg/mL.The flow rate was 3mL/min.The dosage of solventto elute was 3BV.The content of oleuropein was 47.9% in the purified extract of olive leaves.