Planta Med 2008; 74 - PC147
DOI: 10.1055/s-0028-1084665

Comparative study of accelerated solvent extraction and supercritical fluid extraction of total phenolics and flavonoids from Sideritis raeseri subsp. attica and study of antioxidant activity

G Papaefstathiou 1, P Polychronopoulos 1, N Aligiannis 1, AL Skaltsounis 1, S Mitaku 1
  • 1University of Athens, Faculty of Pharmacy, Department of Pharmacognosy and Chemistry of Natural Products, Zografou Campus, 15771, Athens, Greece

The genus Sideritis (Lamiaceae) comprises 8 species and 7 subspecies according to Flora of Greece [1, 2]. Sideritis species are often used in Mediterranean countries as herbal tea, and the common Greek name of these plants is „mountain tea“. Moreover, these plants are used in Mediterranean traditional medicine for their antiinflammatory, antirheumatic, and antimicrobial activities [3, 4]. Over the years, the phytochemistry of the genus Sideritis (Lamiaceae) has been studied and several flavonoid aglycones and glycosides have been identified. It is well known that these natural compounds possess a good antioxidant activity [5].

In continuation of our investigation on the composition of Sideritis species from Greece [6], the total phenolic content and free radical scavenging activity (DPPH) of extracts from Sideritis raeseri subsp. attica were evaluated. These extracts were obtained using A.S.E. (Accelerated Solvent Extraction) and S.F.E. (Supercritical Fluid Extraction) techniques, in several conditions. S.F.E. extraction conditions were determined by varying pressure, ethanol concentration, and extraction time (Pressure was varied from 90 to 300bar and ethanol from 0–20%). In addition, the flavonoid content of the above mentioned extracts was compared with conventional extraction method. HPLC analysis of the acquired extracts showed that the use of A.S.E. gave the best results for flavonoid glycosides, whereas S.F.E. gave higher yields of flavonoid aglycones.

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2. Strid, A. Tan, Kit. (1991) Mountain Flora of Greece. Edinburg University Press, Edinburg.

3. Villar, A. et al. (1986) Plant Med. Phytother 10:31–36.

4. Diaz, R. M. et al. (1988) Planta Med. 54:301–304.

5. Gabrieli C. N. et al. (2005)J. Ethnopharmacol. 96:423–428

6. Aligiannis, N. et al. (2001)J. Agric. Food Chem. 49:811–815.