Scientific basis for rational use of the bark Quercus robur in pharmaceutical practice

Introduction. Quercus robur L. is a woody plant of the Beech family Fagaceae, growing in the European part of Russia. The official raw material of Quercus roburL\\stbe bark ofyoung branches, but it isalso advisable to study the perennial bark ofthe stem parts in order to discover important biologically active compounds. Currently, the issue of complex processing of perennial stem parts of Quercus roburbark has not been resolved, therefore perennial oak bark is practically not used in wood processing. Purpose of the study. Comparative phytochemical analysis of the aboveground organs of Quercus robur - the bark of perennial stem parts of industrial raw materials obtained as waste ofthe wood processing industry and pharmacopoeial raw materials of Quercus robur. Material and methods. The objects of the study were samples of the bark Quercus robur L.: pharmacopoeial bark (Kras-nogorskleksredstvaJSC, Krasnogorsk) and perennial stem bark obtained as production waste from the wood processing company 000 «DUO». Also, the objects of the study were alcohol extracts at various concentrations of ethyl alcohol (50,60,70,80%), as well as on chloroform ofthe chemically pure grade in a ratio of 1:5 (raw material-extractant) based on the pharmacopoeial bark of Quercus robur L. and perennial bark. As methods for analyzing the extracts, chromatography in a thin layer of sorbent was used; the analysis was carried out on PTSKh-AF-A-UV plates ofthe "Sorbfil" brand. Chromatography was carried out ascending in a solvent system chloro-form-ethanol-water (26:16:3). The detection of spots of substances was carried out by viewing chromatograms in lamps with UV light with wavelengths of 254 nm and 366 nm. In addition, the chromatograms were processed with the phosphoric tungstic acid (FVA) reagent, followed by heating to 100 ° С for the development of flavonoids and other compounds.A spectrophotometric study was carried out to quantify the content of the sum of tannins and flavonoids in raw materials based on the bark of an Quercus robur. Forthese purposes, we used the method of direct and differential spectrophotometry on a spectrophotometer - "SF-2000" (Russia) in cuvettes with a layerthickness of 10 mm. 95% ethyl alcohol was used asa solvent. The reference solution is95% ethyl alcohol. Results. Comparative spectrophotometric, titrimetric and chromatographic studies of alcohol extracts of concentrations of 50,60,70, 80%, as well as chloroform extracts of Quercus robur bark samples: pharmacopoeial raw materials and perennial oak bark have been carried out. It was found that 60% alcoholic extract from pharmacopoeial bark and perennial bark are distinguished by a relatively high content of flavonoids. In particular, the content of flavonoids in terms of cynaroside in oak bark (pharmacopoeial raw material) for 60% alcohol is 1.69%, in perennial bark - 1.18%. The content of tannins in oak bark samples was determined by titrimetric method of analysis: in pharmacopoeial bark6.40%, in perennial bark-8.90%; spectrophotometric method: in the pharmacopoeial cortex-1.70%, in the perennial cortex -15.20%. Chromatographic analysis of the studied samples of the Quercus robur bark extracts in comparison with the standards revealed the presence of the flavonoid quercetin (Rf ~ 0.82) and theflavonol glycoside rutin (Rf ~ 0.2) in both samples. Conclusion. The expediency of using non-pharmacopoeial raw materials - perennial oak bark, which is today a waste of the wood processing industry, is shown in the framework of solving urgent problems of nature management, ecology and waste-free production, as well as using raw materials as an affordable and inexpensive source of valuable phenolic BAS.

Quercus robur L, Fagaceae, Quercus robur L, Fagaceae, bark, hydro-alooholic extracts, spectrophotometry, permanganatometry, wood processing, waste-free production