Development of assay methods for tannins content in Rheum officinale B.

K.N. Semenyuta, V.A. Kurkin, A.A. Shmygareva, A.N. Sankov

Orenburg State Medical University, Orenburg

Rheum officinale B. is a medicinal plant widely used in the traditional medicine of the European Union, United Kingdom, Japan and China and is promising for use in national pharmacy. Rheum officinale B. and Rheum palmatum L. are closely related plant species that contain two dominant groups of biologically active substances — anthracene derivatives and tannins. The aim of the study was to determine the optimal conditions for extracting tannins from the Rheum officinale B. and develop an assay technique. The study objects were the roots of Rheum officinale B. Electronic spectra were measured using Unico 2800 UV spectrophotometer. Solutions UV spectra of water extracts from raw materials were studied. Catechin was used as a reference standard, which had a maximum absorption at a wavelength of 282±2 nm. Optimal conditions for extracting tannins from the Rheum officinale B.: extraction  solvent — water; raw material/extraction solvent ratio — 1:50; extraction time — 15 minutes in a boiling water bath. Assay method for tannins content in Rheum officinale B. by spectrophotometry on the basis of catechin at the analytical wavelength of 282±2 nm has been developed. The content of tannins in the Rheum officinale B. was 25.35%.

Keywords: Rheum palmatum L., Rheum officinale B., roots, tannins, catechin, standardization, spectrophotometry.

For citation: Semenyuta K.N., Kurkin V.A., Shmygareva A.A., Sankov A.N. Development of assay methods for tannins content in Rheum officinale B. RMJ. 2020;11:78–80.