Title Ilguolinių kulkšnių augalų (Astragalus cicer L.) fenolinių junginių ir antioksidacinio aktyvumo tyrimas
Translation of Title The investigation of phenolic compounds and antioxidant activity of cicer milkvetch (Astragalus cicer L.) plants.
Authors Matulaitytė, Monika
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Pages 50
Keywords [eng] cicer ; Astragalus ; milkvetch ; antioxidant
Abstract [eng] The aim: to examine quantitative composition of phenolic compounds and flavonoids in raw materials of Astragalus cicer L. cultivated in Lithuania, also to assess antioxidant activity of extracts. The objectives of the study: 1) To optimize the extraction conditions of phenolics compounds from A. cicer raw materials. 2) To determine the quantitative composition of total phenolic compounds and flavonoids and their variation patterns in A. cicer raw materials using spectrophotometric methods. 3) To evaluate antioxidant activity and its variability in extracts of A. cicer raw materials using three modeling (DPPH, ABTS and FIC) systems. 4) To determine correlation between quantitative composition values of total phenolic compounds, flavonoids and antioxidant activity. Research metodology: The study was performed using samples of the raw materials of cultivated A. cicer. The extraction was carried out in ultrasonic agitation 15min when extraction temperature - 50ºC and extractant – 70% (V/V) ethanol. To establish the total content of phenolic compounds the Spectrophotometric Folin-Ciocalteu method was used and results were expressed using calibration curve of gallic acid. Spectrophotometric method using rutin and reaction with AlCl3 has shown the total content of flavonoids. Antiradical compounds activity was assessed by trolox curve using spectrophotometric ABTS radical scavenging method. Extracts antioxidant activity, were expressed as a percentage, measured using DPPH and FIC (Fe 2+ ion binding method) methods. Results and conclusions: A. cicer raw materials was characterized by the total phenolics and flavonoids quantitative configurations of variability: the highest number of phenolic compounds was determined in A. cicer seeds (27.165 ± 1.923 mg/g), and the highest amount of flavonoids found in A. cicer the raw materials of leaves (3,974 ± 0,080 mg /g ). It was found that A.cicer extracts has antioxidant activity in all three in vitro modeling systems. The highest DPPH radical scavenging activity was noted in seed extracts (61.61 ± 0.889%). The biggest antiradical activity using ABTS radical scavenging method, discovered by A. cicer lyophilized tillering stage of raw extracts (TE 12.008 ± 0.319 µmol/g). The strongest chelating properties using the FIC method was found in seed extract (95.405 ± 0.121%). Strong correlation was determined between the total amount of phenolic compounds and antioxidant activity, measured by DPPH and FIC (0.820 and 0,815 respectively) methods. A strong correlation was also determined between the total flavonoid content and antioxidant activity, which was evaluated by ABTS radical - cations scavenging (0,843) and FIC (0.853) methods.
Dissertation Institution Lietuvos sveikatos mokslų universitetas
Type Master‘s Thesis
Language Lithuanian
Publication date 2016