OPTIMAL CONDITIONS FOR SELECTIVE EXTRACTION OF FLAVONOIDS FROM FLORES SOPHORAE JAPONICAE

Abstract

Protunkevich О. О., Prisyazhnyuk K. A., Rakipov I. M., Marchenko S. I., Ponomareva L. A. OPTIMAL CONDITIONS FOR SELECTIVE EXTRACTION OF FLAVONOIDS FROM FLORES SOPHORAE JAPONICAE. Актуальні проблеми транспортної медицини / Actual problems of transport medicine / 2019;2(56):132-138. ISSN 1818-9385 DOI http://dx.doi.org/10.5281/zenodo.3251637 http://aptm.org.ua OPTIMAL CONDITIONS FOR SELECTIVE EXTRACTION OF FLAVONOIDS FROM FLORES SOPHORAE JAPONICAE О. О. Protunkevich, K. A. Prisyazhnyuk, I. M. Rakipov, S. I. Marchenko, L. A. Ponomareva Odessa National Polytechnic University E-mail: o.o.protunkevych@opu.ua Summary Rutin and quercetin are part of many phytopreparations with antioxidant and anti-inflammatory effects. Flores Sophorae japonicae contain up to 20 % rutin. The authors investigated the optimal conditions for the selective extraction of rutin and quercetin from Flores Sophorae japonicae with alkyls and alkyl acetates. Flores Sophorae japonicae was harvested according to the requirements of the State Pharmacopoeia of Ukraine. For research, the raw material was ground to particles of 3-5 mm in size. Flavonoids from Flores Sophorae japonicae were isolated with 70 % ethanol, the primary aqueous-alcoholic extract was used for further selective extraction of rutin and quercetin with organic solvents (butanol, ethyl acetate and butyl acetate). The quantitative content of total flavonoids (X %, in terms of rutin) in the extracts was determined by the photometric method according to the levels of complexation with aluminum chloride. In the primary water-alcohol extracts, the content of flavonoids was 0,132 ± 0,06 %. To evaluate the properties of alkyls and alkyl acetates, to extract rutin from primary extracts, a two-phase selective extraction was performed in a system — water-alcohol extract: organic solvent (butanol, ethyl acetate and butyl acetate). The selective properties of solvents were evaluated by the quantitative content of flavonoids in organic phases. For crystallization of flavonoids, organic phases were concentrated using a rotary evaporator. Based on experimental data for butanol, ethyl acetate and butyl acetate, quantitative extraction characteristics were calculated, such as the distribution coefficient (D) and the levels of rutin extraction (R, %). It was determined that butyl acetate showed the most pronounced ability of selective extraction (R = 82.7 %). In the ethyl acetate and butanol phases in the cold, crystallization of flavonoids was observed during the day. The precipitates were studied by TLC, IR spectrophotometry and mass spectrometry. Chromatograms showed spots with yellow-green fluorescence and corresponding Rf = 0.5 (rutin) and Rf = 0.81 (quercetin). In the infrared spectra of flavonoid precipitation, absorption bands characteristic of phenolic and alcoholic hydroxyl groups are visible (lanes 1660, 1610, 1580, 1510, 1460 cm-1) and the “fingerprint” area of 800-1200 cm-1, which confirm the presence of rutin. The mass spectrum of precipitation has a peak 60, which corresponds to the mass of glucose and a peak 302, which confirms the presence of quercetin. It was determined that butanol proved to be the optimal selective extractant of flavonoids. Key words: rutin, quercetin, flavonoids, selective extraction.