Flavonoids from fruits of japanese sophora (Sophora japonica L.)

Introduction. In scientific medicine buds and fruits of Sophora japonica L. are used to obtain medicines as medicinal plant raw materials. The State Pharmacopoeia of the Russian Federation of the XV edition includes a pharmacopoeia article on raw materials «Sophora Japonica fruits» FS.2.5.0130. The section «Quantitative determination» provides for the quantitative determination of the amount of phenolic compounds by spectrophotometry in terms of genistein (4',5,7-trihydroxyisoflavone). The «Identification» section includes the identification of the authenticity of this raw material by TLC using a standard solution of soforicoside (4'-O-β-D-glucopyranoside of genistein). In this regard, it is advisable to provide a scientific justification for the standardization of this raw material in terms of the content of flavonoids in both sections. The aim of this work is to study the flavonoid composition of Japanese sophora fruits cultivated in the Krasnodar region. Material and methods. The research material was the air-dry fruits of Japanese sophora, cultivated in the Krasnodar Territory. Flavonoids were isolated using column chromatography on silica gel and polyamide. The chemical structure of the isolated phenolic compounds was studied using UV, 1H-NMR, 13C-NMR spectroscopy, mass spectrometry, as well as the results of chemical transformations. Results. The research material was the air-dry fruits of Japanese sophora, cultivated in the Krasnodar. As a result of the studies conducted from the fruits of Sophora japonica L., along with flavonoids known for this plant, genistein (4',5,7-trihydroxyisoflavone), sophoricoside (4'-O-β-D-glucopyranoside of genistein), genistin (7-O-β-O-glucopyranoside of genistein) and kaempferol-3-O-sophoroside [3-O-(2"-β-D-glucopyranosyl)-β-D-glucopyranoside 3,5,7,4'-tetrahydroxyflavone] were first isolated 4'-O-α-L-rhamnopyranoside of genistein) and 4'-O-rutinoside of genistein [genistein-4'-O-(6"-α-L-rhamnopyranosyl)-β-D-glucopyranoside], which are new natural compounds. Conclusion. As a result of the studies, 6 flavonoids were isolated from the fruits of Sophora japonica L., including 4'-O-α-L-rhamnopyranoside of genistein) and 4'-O-rutinoside of genistein [genistein-4'-O-(6"-α-L-rhamnopyranosyl)-β-D-glucopyranoside], which are new natural compounds. Taking into account the fact that soforicoside is the dominant and diagnostically significant isoflavone, we consider it advisable to use this flavonoid as a standard sample in the “Quantitative determination” section.