JUSTIFICATION OF THE METHODS FOR THE QUALITATIVE AND QUANTITATIVE DETERMINATION OF FLA-VONOIDS IN THE GRASS OF SPECIES OF THE GENUS MONARDA

The herb of plants of the genus Monarda L. is most often known for its essential oil the main components of which are thymol and carvacrol. However flavonoids contained in the raw materials of this plant are of great interest. The literature reports on the presence in the herb of species of the genus Monarda L. quercetin, luteolin, rutin, hesperidin, naringinin; howeve, these data are contradictory. It is known that when determining the content of the amount of flavonoids, recalculation is carried out in different cases for luteolin or rutin, which have different spectrum characteristics. This paper discusses the results of a comparative study of the flavonoid composition of some species of the genus Monarda: Monarda fistulosa L., Monarda didyma L., Monarda bradburiana L. Back., Monarda citriodora L., Monarda × medioides W.H.Duncan as a promising source of biologically active compounds. As a result of a comparative chromatographic study, the presence of flavonoids was detected upon detection at a wavelength of 366 nm and after treatment with an alcohol solution of aluminum chloride. In all treatments, the presence of cynaroside, rutin, quercetin, luteolin is not confirmed. Using column chromatography on silica gel L 40/100, from the herb of Monarda fistulosa the flavonoid substances for the first time were isolated – isorhoifolin (7-O-rutinoside of apigenin) and linarin (7-O-rutinoside of acacetin), which have n-butanol–acetic acid–water (4 : 1 : 2) in the solvent system Rf values are about 0.5 and 0.6, respectively, and also dimydin (7-O-rutinoside of sakuranetin). It was determined that in all UV spectra of extracts from herb of studied species of the genus Monarda of the species, a bathochromic shift of the long-wavelength band is observed in the presence of 3% alcoholic solution aluminum chloride, which confirms the presence of flavonoids. Under the conditions of differential spectrophotometry, an absorption maximum is observed in the region of 392–396 nm, which indicates the feasibility of using isorhoifolin in the analysis technique with an absorption maximum at a wavelength of 394 nm. As a result of the work a method of quantitative determination of the amount of flavonoids of the herb of the Monarda has been developed. The optimal parameters were determined: 60% ethyl alcohol, the ratio of "raw material to extractant" – 1 : 50, extraction time – 60 minutes, analytical wavelength at 394 nm. It was determined that the content of the total of flavonoids calculated on isorhoifolin in all samples studied varies from 4.53% to 8.73%.