Investigation of Total Phenolic, Flavonoid Content and Antioxidant Activity of Onobrychis Megataphros Leaf Extract

Abstract

This study aims to determine the total phenolic, flavonoid and antioxidant activity levels of Onobrychis megataphros plant leaves. The O.megataphros (Sainfoin) samples were collected, laid on blotting papers in shady places away from sunlight and dried. After that, the dried plant samples were pulverized. The powdered samples were extracted with methanol using Soxhlet device. The methanol was removed by evaporation in a rotary evaporator and stored at +4ºC until the experiment starts. Phenolic and flavonoid content and antioxidant activity properties of O.megataphros plant leaf extracts were examined. The determination of the Phenolic and flavonoid performed according to Zengin et al. (2015a). The sample and blank absorbance was read at 415 nm after 10 min incubation at room temperature. Absorbance of the blank was subtracted from that of the sample. Total flavonoid content was expressed as equivalent to routine. Total antioxidant activity of the samples was evaluated by phosphor molybdenum method. Sample solution (0.2mL) was combined with 2mL of reagent solution (0.6M sulfuric acid, 28mM sodium phosphate and 4mM ammonium molybdate). The sample absorbance was read at 695nm after 90 min incubation at 95°C. As a result, it was determined that the total phenolic content in O.megataphros plant leaf extracts was 20.62±0.15 mg GAE/g extract and total flavonoid content was 24.55±0.22 mg QE/g extract. At the end of this research work, it is concluded that TAS and TOS levels increased with the increase in concentration.