IMPACT OF SOLVENT EXTRACTION TYPE ON TOTAL POLYPHENOLS CONTENT AND BIOLOGICAL ACTIVITY FROM TAMARIX APHYLLA (L.) KARST

Abstract

Secondary metabolites of an arabo-saharan tree Tamarix aphylla (L.) Karst. Were extracted from dry powdered leaves with different solvents: aqueous methanol; aqueous ethanol, aqueous acetone and distilled water. Total phenolic content of the four extracts were determined by Folin Ciocalteu method and their antioxidant activity was assayed through in vitro radical scavenging activity using DPPH· assay. The results showed that mixture water-methanol was better than water-ethanol, wateracetone and water for extraction bioactive compounds in particularly total polyphenols from Tamarix aphylla leaves. The average total phenol content of aqueous methanol extract was 262.26mg GAE/100g dry weight lyophilized extract. However, all extracts were free-radical inhibitors but aqueous acetone extract was more potent than aqueous ethanol extract and two others extracts. In order of effectiveness (EC50), the potent inhibitors were from water-acetone extract (0.080mg/ml) > water-ethanol extract (0.140mg/ml)>water extract (0.173mg/ml)> Water-methanol (0.911mg/ml).