Abstract
Introduction. Tannins are widespread in the plant world. Their quantitative determination in medicinal plant raw materials requires the use of titrimetric and spectrophotometric assays, each of them has its own advantages and disadvantages. More in-depth information on tannins contained in the raw material is needed to completely describe the metabolome of yellow iris (Iris pseudacorus) rhizomes. Objective: to determine certain groups of tannins in the rhizomes of yellow iris growing in the Moscow Region. Material and methods. The investigation object was the dried rhizomes of wild yellow iris, which had been harvested in autumn in the Shatursky District, Moscow Region. The content of tannins in the raw materials was determined titrimetrically (permanganatometrically) and spectrophotometrically on a tannin basis and after precipitation with a collagen solution on a gallic acid basis. Results. The yellow iris rhizome content of tannins, namely the total amount of tannins precipitated with a 1% solution of collagen and phenolic compound, was found after extraction of condensed tannins. The specific absorbance was calculated for the aqueous solutions of standard samples of tannin and gallic acid used in the work at experimental wavelengths. Conclusion. Extended information was obtained on the content of tannins in the rhizomes of yellow iris growing in the Moscow Region.