Phenolic compounds profile and antioxidant activity of Dorystoechas hastata L. Boiss et Heldr

Abstract

Phenolic compound profile and antioxidant activity of methanol, acetone, ethyl acetate, water and petroleum ether (b.p. 40–60 °C) extracts of Dorystoechas hastata, endemic to Turkey and being consumed as herbal tea by local inhabitants, have been investigated. HPLC–DAD analysis indicated the presence of chlorogenic, caffeic, p-coumaric, ferulic and rosmarinic acids as phenolic acids, quercetin, kaempferol and apigenin as flavonoids and carnosic acid and carnosol as diterpenoid antioxidants in the plant. Petroleum ether, methanol and water extracts of D. hastata were found to be very effective antioxidative extracts. Petroleum ether extract, having the highest amount of carnosic acid and carnosol contents (531.3 and 389.9 mg/g DW, respectively) among all solvent extracts, was found to have the highest antioxidative potential based on the individual antioxidant activity assays; DPPH , ABTS +, TBARS and total phenolic content, expressed as IC 50, TEAC, EC 50 and TPC values, respectively, and also on the principal component analysis. It exhibited significantly high TEAC (7.1 mM trolox) and low EC 50 (54.5 μg/mL) values, indicating the strong potential in in vitro radical scavenging and in inhibiting lipid oxidation. Water extract, with its extremely low IC 50 value of 4.9 μg/mL in DPPH radical scavenging and significant TEAC (4.8 mM trolox), EC 50 (64.4 μg/mL) and TPC (116.7 mg GAE/g DW) values, was found to be the second highest in antioxidative potential among all extracts. TPC value of methanol extract (147.3 mg GAE/g DW) was found to be significantly higher than the other extracts studied. The results showed that D. hastata can be used as a potential antioxidative edible source due to its different classes of phenolic compounds and strong antioxidative capacity.