Silicon is biologically important element that is necessary not only for plant, but for all living organisms. Silicon was discovered in all plant organs, where its much quantity accumulates in plan cell walls of leaf and root, giving them a mechanical durability and resistance against abiotic and biotic stresses. Earlier, it was supposed that the silicon was absorbed by plants in form of monosilicic acid and then being deposited as phytoliths or accumulated in epidermal plant cells. Moreover the silicon is not only a basic structural element, but it controls many biological and chemical processes. Water soluble monosilicic acid enters into reaction with metals, organic compounds, showing properties of weak acid. Gels of silicic acid can be a catalyst and a matrix, on which the inner cellular synthesis of organic compounds occurs. In the present study the method to determinate three forms of silicon in plants, such as free, easily hydrolyzed and tightly combined is given. Thus, the part of silicon, 0.5-0.7% was observed in protein preparation of leaves of amaranth. Protein was divided into two fractions, albumins and globulins by precipitation with ammonium sulfate. After that each protein fraction was divided into two by Sephadex, where one of which come out in inner volume of gel, and second one come out in outer volume of gel (G-75). The gel distribution into fractions was of the same type characteristics. The tightly combined silicon was absent in high molecular fraction of albumins and globulins. Most of the silicon was discovered in high molecular fraction of globulins, where 80% of the element was represented by an easily hydrolyzed form. The silicon combined with proteins apparently is in a form of orthosilicic ester of hydroxy-amino acids; however it cannot be excluded that there is the formation of SiN bonds with free amino groups. Biophile silicon is a part of plant silicon (organogenic), which is basically in the form of orthosilicic esters bonded with proteins, phospholipids and pectins that are the plant components being assimilated primarily by human’s organism. In our opinion, this fraction of silicon as a microelement should be taken into account in evaluation of nutritional, forage and pharmaceutical values of plant raw material.

Relevance. Nowadays the popularity of Chamaenerion angustifolium as a medicinal plant and as a tea is growing noticeably. Fireweed is an eclogically plastic species, that does not require high soil fertility and is widespread in Russia. Medical and food industries use leafs as a row material of fireweed. Series of phytochemical studies of Chamaenerion raw material have shown that it contains a wide variety of pharmacologically significant compounds, that accumulate as a result of both primary and secondary metabolism. The most important groups, formed as a result of secondary metabolism, are polyphenols, including flavonoids, phenolic acids and ellagitannins (including enothein B). Concentration of these chemical compounds equals 15% and even hither of the raw material (leaf).The aim. Identification of variability and relationships between the content of various groups of phenolic compounds in raw material of Chamaenerion angustifolium, depending on ecological conditions.Methods. At the first stage of our work was used the cartographic method. Were studied specimens from 27 points, growing in ecologically different areas of the Moscow, Kaluga and Yaroslavl regions. Phenolic compounds were determined using a spectrophotometer: flavonoids in terms of rutin, tannins and the amount of phenolic compounds, using the Folin-Ciocalteu reagent in terms of gallic acid.Results. The content of polyphenols, tannins and flavonoids in raw material of fireweed, collected in different ecological and soil aspects, was measured. Measurement results were compared, using correlation analysis. As the result of content analysis, it was found that the content of polyphenols in the leaves ranged from 9 to 11%, the content of flavonoids fell within the chain range of 2.5-3.5%, tannin content – 5.0-6.5%. A close correlation was found between the content of phenolic compounds and tannins (R=0.972). It indicates, that the shikimate pathway is the main process of biosynthesis secondary metabolites in the Chamaenerion angustifolium plant. Also it means the leading role of local ecological conditions of the studied areas.

Relevance. Currently pharmaceutical industry, food industry and chemical laboratories demonstrate an increasing interest in natural plant sources, including Chamaenerion angustifolium. Modern researches reveal more and more medicinal properties of this plant. For this reason, the demand for the use of fireweed as a medicinal plant, especially its leaves and flowers, is very high. It means, that the study of biological properties, chemical composition, ecological and landscape features of fireweed is of scientific and practical interest.Methods. This article contains information from literary sources about pharmaceutical, chemical, biological, ecological and geographical studies of Chamaenerion, its results and recommendations. Obtained from other researches information was systematized by research topics and presented in a logical sequence.Results. The issues of using this plant in medicine and food industry are also considered here, along with the discription of collecting natural fireweed problems and the mail ways of cultivating this species. The modern condition of fireweed research is shown, a detailed analysis of fireweed biological and ecological characteristics is carried out and on this basis, the main directions for further work on the introduction of Chamaenerion into culture for its more complete and rational use in medicine and in the food industry are outlined in this article. The article presents an analysis of the problems that arise during the introduction, in particular, the improvement of vegetative reproduction techniques, the selection of populations promising in terms of the phenolic compounds content and the possibility of target compounds content in plants by the exogenous regulation.Conclusion. Despite the presence of a relatively large quantity of works devoted to Chamaenerion, some research topics are poorly covered. For example, the topic of cultivation and the use of growth regulators. The most promising directions for the future study of Chamaenerion are indicated in this article.