Optimization of the Method of Quantitative Definitions of Flavonoids in the Raw Materials of "Menyanthidis Trifoliatae Leaves"

The aim of the study is to optimize the methodology of quantitative determination of flavonoids in the leaves of Menyanthidis trifoliatae. In official medicine, the leaves of Menyanthidis trifoliatae are used for anorexia and dyspeptic disorders. In the current regulatory documentation (State Pharmacopoeia of the Russian Federation), it is proposed to evaluate the quality of raw materials by the content of the amount of flavonoids in terms of rutin using spectrophotometry. This technique is based on the ability of flavonoids containing free aromatic hydroxyl groups to form colored products with diazotized sulfanilic acid. The disadvantage of this technique is the long and time-consuming stage of cleaning raw materials from certain groups of lipophilic substances, which can also react with diazotized sulfanilic acid to form colored products. We have proposed a selective method for the quantitative determination of flavonoids in the herb trifoliate by the method of spectrophotometry in terms of rutin. The technique is based on the ability of flavonoids to form stable colored complexes with aluminum chloride. We have selected the optimal conditions for extraction and complexation reaction of aluminum chloride with flavonoids of M. trifoliatae extract. The proposed method has been validated and is suitable for use in an analytical laboratory.