engleski

Solid Phase Extraction of Polyphenolics from Propolis

Propolis is a complex mixture of which polyphenolics, flavonoids and phenolic acids are the most important for the pharmacological activity (e.g. antioxidative, antiimmflamatory, immunomodulatory, antimicrobial). To analyse such a mixture there is necessity for purification and concentration, both of which can easily be achieved by solid phase extraction. As phenolic acids and flavonoids present weak acids we used mixed-mode anion-exchange and reversed-phase sorbent syringe cartridges (Oasis&reg ; ; MAX) for separation. Separation was done on the mixture of standards (phenolic acids: ferulic, caffeic, isoferulic, p-coumaric ; flavonoids: apigenin, chrysin, naringenin, galangin, quercetin, pinocembrin, kaempferol, pinostrobin, rhamnetin, sakuranetin and tectochrysin) and the mixture of propolis (samples from Pelješac, Vis, Metković, Omiš, Sisak, Sinj and Veliki Zdenci) using binary gradient method of 2% acetic acid in methanol and 2% acetic acid in water modified with 10% of water and methanol, respectively. Collected fractions were analysed using high performance liquid chromatography with DAD detector. The complete separation of standards of phenolic acids from flavonoids was possible, phenolic acids being the eluted first. Recovery rate of flavonoids was rather high (94%) compared to phenolic acids (66%). Clear separation of polyphenolcis from propolis using binary gradient method was not achieved only for naringenin being the most polar flavonoid from standards used.

SPE; Propolis

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