Publication details
HPLC profiles of polyphenolic compounds and estimation of antioxidant potential in sea buckthorn plant parts
| Authors | |
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| Year of publication | 2013 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | Predominant medical effect of many plants and herbs is related to the presence of polyphenolic secondary plant metabolites commonly known as flavonoids. Different classes of flavonoids are synthesized as a response to the ambient stimuli (climate, stress, mold attacks etc.) and accumulate in various cells and plant parts. The antioxidant potential and selected flavonoids content in sea buckthorn (Hippophaë Rhamnoides L.) plant part materials (stems, leaves and fruits) has been investigated during one vegetative cycle. New RP-HPLC method using gradient elution for determination of 10 polyphenols, namely catechin, epicatechin, rutin, quercetin, quercitrin, kaempferol, gallic acid, p-coumaric acid, caffeic acid and ferulic acid has been developed. Significant part of method development included optimization of extraction step for sample matrix removal. As the most suitable, liquid-liquid extraction of methanolic plant solutions using diethylether was found. Proposal method comprised also optimization of chromatographic conditions and final validation. Total antioxidant activity (TAC) of sea buckthorn extracts was determined spectrophotometrically by methods based on DPPH and ABTS free radical scavenging abilities. Consequently, total content of polyphenols (TPC) was estimated by Folin-Ciocalteu method. All spectrophotometrically measured characteristics were expressed as gallic acid equivalents and compared. Acceptable linear correlation between TAC and TPC was observed (R2 = 0,983) which indicates prevalent responsibility of flavonoids for total antioxidant activity. In comparison with stems and leaves, significantly lower content of polyphenols was observed in fruits. In leaves and stems, the most representative analytes were catechin, epicatechin and gallic acid. While the content of catechin in stems increased from April to October (95 – 202 mg/kg), catechin in leaves continuously decreased in the same time (167 – 31 mg/kg). |