STUDY OF EFFECT OF EXTRACTION CONDITIONS ON THE BIOCHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF <i>ARTEMISIA ABSINTHIUM</i> BY HPLC AND TLC

Abstract

The purpose of the present study was to investigate the effect of extraction temperature and solvent type on the biochemical compounds and antioxidant capacity of Artemisia absinthium. Alternations on biochemical composition and antioxidant potential of extracts were studied due to various extraction conditions, i.e, temperatures (30–60 °C), solvent types (methanol, ethanol, and acetonitrile), and solvent concentration (25–100%). Total phenolic content (659–1033 mg gallic acid equivalents (GAE)/100 g dry weight (DW)) and total flavonoid content (259–392 mg catechin equivalents (CE)/100 g DW) were examined in all samples. Radical scavenging capacities were determined using the 2,2-diphenyl-2-picrylhydrazyl (DPPH) (51–79%), ferric reducing antioxidant power (FRAP) (151–287 µ M Trolox equivalents (TE)/100 g DW), and 2,2′-azino-di-[3-ethylbenzthiazoline sulphonate] (ABTS) (17–33.7 mM TE/g FM) methods in triplicate. Plant extracts obtained by 75% methanol at 45°C showed the highest antioxidant capacity, whereas extracts obtained using 75% methanol at 60°C had the highest levels of total phenolics. RP-HPLC (detection at 205 and 258 nm) and thin-layer chromatography (TLC) of analyses did not detect artemisinin in extracts of leaves. On the other hand, high-performance liquid chromatography (HPLC) results showed that extraction solvents had significant effects on anabsinthin amount. This was supported by the result that showed highest anabsinthin extraction was obtained by 75% methanol (16.58 µg/g DW), but lowest by 25% methanol (9.45 µg/g DW).