Validation of the methodology of quantitative determination of flavonoids in the herbae of Cirsium arvense (L.)

Relevance. One ofthe main groups of active substances ofthe Cirsium arvense L. are flavonoids, among which apigenin predominates. An urgent problem is the study of new types of medicinal plant raw materials and their introduction into medical practice, which requires research on the developmentof methodsforthe quantitative determination of the main group of BASand validation ofthe method. The purpose ofthe work. Validation evaluation ofthe method of quantitative determination of flavonoids in the herba ofthe Cirsium arvense L. Material and methods. The object ofthe study is samples ofthe herba ofthe Cirsium arvense L. The quantitative determination of flavonoids was carried out by differential spectrophotometry with the selection of optimal extraction conditions, and the method was validated. Results. A method for the quantitative determination ofthe amount of flavonoids in terms of apigenin (Amax = 388 ± 2 nm) was developed. The optimal parameters of extraction of flavonoids were determined: the extractant-ethyl alcohol 40%, the ratio of raw materials and extractant 1: 30, the degree of grinding - 2 mm, the extraction time-30 minutes, three-time extraction, the complexing agent-1 ml of 2% aluminum chloride solution, the reaction develops within 45 minutes and the complex remains stable for 1 hour. The content ofthe sum of flavonoids in terms of apigenin is 2.78 ±0.09%. Validation ofthe method wascarried out according to thefol-lowing parameters: linearity, correctness and precision. It was found that within the limits ofthe measured concentrations (optical density 0.241-0.389), the dependence of the apigenin content on the theoretical content of flavonoids in the herba ofthe Cirsium arvense L. is linear. The correctness ofthe method was established by measuring the quantitative content ofthe sum of flavonoids in solutions with a known concentration of apigenin and it was found that the values lie within the confidence intervals ofthe corresponding average results. Precision wasstudied by the indicators-repeatability (convergence); intra-laboratory and inter-laboratory reproducibility, while it was found that the relative error of the average result did not exceed 10%. Conclusions. The linear nature, correctness and precision ofthe developed methodology for the quantitative determination of flavonoids in the herba ofthe Cirsium arvense L. in terms of apigenin and the possibility of its further use for the standardization ofthe studied raw materials are justified.

validation, Cirsium arvense, herba, flavonoids, apigenin