LICORICE HERB FLAVONOIDS ASSAY METHOD Russian patent published in 2023 - IPC A61K36/484 G01N33/15 

FIELD: chemical; pharmaceutical industry.

SUBSTANCE: invention relates to licorice herb flavonoids assay method. The following is proposed: licorice herb flavonoids assay method by extraction with an organic solvent followed by the use of a spectrophotometric method, which includes a single extraction with 90% ethyl alcohol of air-dried raw materials with an accurate weighing of 1 g, crushed to a particle size passing through a sieve with holes with a diameter of 2 mm, in the ratio of raw material: extractant — 1:50, for 60 minutes, followed by sample preparation, adding 2 ml of a 3% alcohol solution of aluminum chloride to the test solution and determining the optical density by differential spectrophotometry converted to pinocembrin at a wavelength of 310 nm using a standard sample of pinostrobin; the content of the total flavonoids in terms of pinocembrin is calculated using the formula where x is the content of the total flavonoids in terms of pinocembrin,%; D is the optical density of the test solution; D_o is the optical density of a standard sample solution (SS) of pinostrobin; m is mass of raw materials, g; m_o is mass of the standard sample of pinostrobin, g; W is weight loss during drying, %; 1.05 is conversion factor; in the absence of a standard sample of pinostrobin, the calculated value of the specific absorption index at 310 nm, equal to 680 is used, and the content of the total flavonoids in terms of pinocembrin is calculated using the following formula where x is the content of the total flavonoids in terms of pinocembrin,%; D is the optical density of the test solution; m is mass of raw materials, g; 680 is specific absorption index (E) of a standard sample of pinocembrin at 310 nm; W is weight loss during drying, %.

EFFECT: above-described licorice herb flavonoids assay method makes it possible to objectively assess the quality of this raw material.

1 cl, 8 dwg, 2 ex