COMPARATIVE STUDY OF THE UV SPECTRA OF VARIOUS RAW MATERIALS OF URTICA DIOICA L

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Urtica dioica L. from Urticaceae family is one of the most popular medicinal plants [1, 2, 3, 4]. In Russia the herbal materials are nettle’s leaves which have haemostatic effect. At the same time abroad, the rhizomes and roots of nettle are the source of drugs with antitumor activity (Prostaforton, Bazoton), and applied for treatment of prostatic adenoma [2, 3]. Above- ground part of Urtica dioica L. is successfully used in urology. Efficient therapy of prostatic adenoma is a timely problem of the contemporary medicine. Despite the positive foreign experience, there are no drugs in our country produced on the basis of the roots with rhizomes of Urtica doica L. It is conditioned by the absence of pharmocopoeial article in the Russian Federation about this kind of raw materials. As we know, the development of regulatory documents is preceded by the investigations for chemical composition of the raw materials and pharmacological properties of the drugs on its basis. The studies, we have carried out previously show the presence of a dense extract of roots with rhizomes of Urtica dioica L. with diuretic activity, which gives evidence about the prospects of galenic drugs on the basis of these plants [5]. We should note, that chemical composition of the roots with rhizomes of Urtica dioica L. is rather complex. This raw material has sterols (β-sitosterol), lectins, polysaccharides, amino acids and other substances [2, 3, 6]. But chemical composition of roots with rhizomes of Urtica dioica is still understudied. So, there are no clear data in literature about the group of substances responsible for antitumor action of drugs from Urtica dioica. Some scientists associate the activity of Urtica dioica drugs with content of lectins, therefore close attention is paid to the analysis of amino acid composition of raw materials [7]. Meanwhile some scientists believe that sterols make a principal contribution into the pharmacological activity manifestation [2, 3]. All above mentioned gives evidence about the timeliness of chemical composition investigation of roots with rhizomes of Urtica dioica L [8]. Further investigations led to the necessity of working out of sterol compounds sum analysis methods in roots with rhizomes of Urtica dioica [9]. We should note that Urtica dioica is a weed plant and it is widespread in Russia, therefore the study of other raw materials of this plant is of big interest. There are some directions in scientific literature about the presence of nephrolytic activity of inflorescences and fruits of Urtica dioica, which gives grounds about the obtainment of new medicinal drugs [6]. The issue of complex processing of aboveground parts of Urtica dioica with procurement of its roots with rhizomes is also discussed. Previously, using thin-layered chromatography we noted that above-ground part of Urtica dioica is characterized by the substances of phenolic nature, while underground parts mainly possess steroid nature substances [8]. The purpose of this paper is comparative phytochemical investigation of different types of Urtica dioica by using a method of spectrophotometry. Samples of air dried leaves, inflorescences and roots with rhizomes, as well as fruits, procured separately from male and female samples were the objects of the study. Procurement of these raw materials was done in July 2015 in Samara Oblast. Based on all types of raw materials, using 70% ethanol we obtained extracts, which were further studied in Specord40 (Analytic Jena) spectrophotometer in cuvets with 10 mm layer for the presence of flavonoid and steroid nature substances. To analyze the steroid nature substances we used a method based on the interconnection of concentrated sulphuric acid with terpenoids. To analyze the flavonoid nature substances we used differential spectrophotometry with alcohol solution of aluminum chloride. Apart from this we used solution of work standard of ergosterin. Preparation of ergosterin solution: about 0.01 g (accurate weighing) of ergosterin work standard is placed into the 25 ml measuring flask mark, then 10 ml are dissolved in concentrated sulphuric acid, heated on a water bath at 70 0C during 1 hour, then it is cooled for ambient temperature, and brought up to the mark by concentrates sulphuric acid and blended. 1 ml of the solution obtained is put into 25 ml measuring flask, brought up to the mark by the concentrated sulphuric acid, blended. The analysis results are shown in figures 1-4. The analysis of the above-ground parts of Urtica dioica shows that leaves and inflorescences have flavonoid nature substances. We should note that there are characteristic distinctive features in the UV spectrums adsorption curves of leaves, root with rhizomes, inflorescences and fruits extracts of Urtica dioica. After the addition of aluminum chloride solution there is a bathochromic shift into long wave field with maximum about 410 nm. The complex with aluminum chloride solution shows the presence of flavonoids (figures 1, 2). Adsorption curves of extracts on the basis of female inflorescences and fruits of Urtica dioica has the same adsorption maxima (about 290 and 330 nm), which shows similar chemical structure. Previously we noted that alcohol-water extract from roots with rhizomes of Urtica dioica on the basis of 70% ethanol did not give characteristic adsorption maxima. Therefore, we used a method based on the interrelation of triterpene compounds with concentrated sulphuric acid for the analysis of total sterine compounds [10, 11, 12]. And the maximum of adsorption from roots with rhizomes with roots of Urtica dioica coincides with maximum of ergosterine, isolated previously, and amounted to 328±2 nm [8, 9]. The adsorption curves are shown in the figures 5 and 6. Conclusions As the result of comparative phytochemical study of extracts from different raw materials of Urtica dioica we have established, that leaves, inflorescences, and fruits are characterized by the presence of flavonoids, while underground part of Urtica dioica has sterols. UV spectrums of extracts from female inflorescences and fruits of Urtica dioica have the same adsorption maxima, which shows the similarity of chemical structure.

About the authors

E. A Balagozyan

Samara State Medical University

Samara, Russian Federation

V. A Kurkin

Samara State Medical University

Samara, Russian Federation

O. E Pravdivtseva

Samara State Medical University

Samara, Russian Federation

References

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