Isolation And Identification Of Polyphenols From Leaves Of Myrtus Communis And Their Antioxident Activity

Myrtus communis is a stenomediterranean species in Italy ,which grows wild in almost all the coastal areas.It has been introduced to Shanghai for many years . As an antiseptic plant in traditional Mediterranean medicine,various polyphenols have been previously detected in myrtle tissues, but in most cases the identity of the compounds were not conclusive. To the best of our knowledge,this is the first report on the study of polyphenols in Myrtus communis leaves from Shanghai,China. We reported data on the extraction and purification procedures, identification of polyphenolic compounds in leaves of Myrtus communis.Their antioxident actiyity was also been investigated:1.The total polyphenol content was determined by Folin–Ciocalteau reagent,and its precision, stability, repeatability and recovery were also inspected.2.To ascertain the optimal condition of extracting the polyphenols from Myrtus communis leaves by ultrasonic method. the author designed a orthogonal experiment. Results indicated 60% ethanol as solvent, ratio of solid to liquid as 1:15,extracting temperature of 75℃and ultrasonic extraction time of 30mins. The extraction efficiency of polyphenols was as high as 3.325%.3.Through analysis of LC-MS,the main active ingredients were identified.Four chromatographic peaks were identified as glucoside of Myricetin and Quercetin.4.Through liquid-liquid extraction ,silica gel column chromatography and Sephadex LH-20 column chromatography, two compounds were isolated:Myricetin-3-O-β-D - glucopyranoside and Myricetin -3-O-α-L -rhamnopyranoside, and their structures were identified by NMR.5.The crude polyphenol of Myrtus communis showed better antioxidant activity than VC and other synthetic antioxidants.