Supervisors info:
Β. Σαμανίδου Αναπλ. Καθηγήτρια ΑΠΘ (επιβλέπουσα), Ι. Παπαδόγιαννης Καθηγητής ΑΠΘ, Λ. Κοβάτση Επίκ. Καθηγήτρια ΑΠΘ
Translated title:
Simultaneous determination of polyphenols and major purine alkaloids in Greek Sideritis species, herbal extracts, green tea, black tea, and coffee by high-performance liquid chromatography-diode array detection.
Summary:
Herein, a high performance liquid chromatography- diode array detection method
for the simultaneous determination of 15 phenolic antioxidants: flavan-3-ols,
(-)-epigallocatechin, (+)-catechin, (-)-epigallicatechin gallate,
(-)-epicatechin, (-)-epicatechin gallate, (-)gallocatechin, a phenolic acid
(gallic acid), a hydrocynamic acid (chlorogenic acid), flavones (apigenin),
flavonols (kaempferol, quercetin, and myricetin), and purine alkaloids
(caffeine, theophylline, theobromine) in different herb extracts, tea, and
coffee varieties. The developed method was validated and successfully applied
in order to determine the polyphenolic content to estimate the antioxidant
activity of the Sideritis species commonly known as Greek mountain tea. To the
best of our knowledge this is the first report on the quantitative
determination of catechins and other polyphenols in Greek mountain tea. Acidic
hydrolysis was necessary for the simultaneous determination of the aglycones of
the target analytes. According to our results, chlorogenic acid, myricetin,
apigenin, catechin and epicatechin gallate are found in the Sideritis species.
Keywords:
Catechins, Flavan-3-ols , Polyphenols, Sideritis, Tea
