Систематизированы данные по химическому составу веществ тритерпеновой и стероидной природы, выделенных из чаги, как выращенной в условиях искусственной культуры, так и произрастающей в природе. Приведены сведения по биологической активности экстрактов из чаги и этих соединений в отношении различных линий клеток рака in vitro и in vivо. Проведённый анализ позволил выявить определенные закономерности в эффективности подавления роста различных линий клеток. Установлено, что наибольшей активностью обладают тритерпеновые соединения, содержащие ОН-группу при С-22 и ненасыщенную связь в боковой цепи.Ключевые слова: чага, тритерпеновые соединения, стероидные соединения, биологическая активность, in vivo, in vitro DOI 10.18097/PBMC20166204369Рисунок. Общая структурная формула тритерпенов ланостанового ряда (а) и стероидных соединений (б).

Synthetic dyes are widely used in the industry; they are chemically stable, difficult to neutralize, and therefore they are a threat to the environment when released into wastewaters. The dyes have a significant impact on plant performance by impairing photosynthesis, inhibiting growth, and entering the food chain and may finally result in the toxicity, mutagenicity and carcinogenicity of food products. Implementation of the dark piment melanin for the adsorption of the synthetic dyes is a new ecologically friendly approach for bioremediation. The aim of the present work was to study the physico-chemical characteristics of melanins from the lichens Lobaria pulmonaria and Lobaria retigera, analyze their adsorption/desorption capacities towards synthetic dyes, and assess the capacity of melanins to mitigate toxicity of the dyes for a common soil bacterium Bacillus subtilis. Unique chelating properties of melanins determine the perspectives of the use of these high molecular weight polymers for detoxification of xenobiotics.

Many members of the Asparagaceae family are used in traditional medicine in different countries and characterized by a high content of biologically active metabolites. In this work, the qualitative composition and quantitative content of the components of methanol extracts from leaves and underground organs of Sansevieria cylindrica Bojer ex Hook, Sansevieria trifasciata Prain, Polianthes tuberosa L., leaves of Yucca filamentosa L. and Furcraea gigantea var. watsoniana (Hort. Sander) Drumm. were determined. Extraction of plant leaves and underground organs using 80% methanol resulted in 5.2–16.7% and 16–25.1% of the total extractive substances consequently. The presence of steroidal saponins in the extracts was shown by thin layer chromatography. Spirostanol saponins were predominate in the extracts from leaves of Y. filamentosa, F. gigantea and underground organs of S. cylindrica, S. trifasciata, P. tuberosa, furastanol saponins – in the extracts from leaves of S. cylindrica and S. trifasciata. The content of terpenoid and phenolic compounds in the extracts established using spectrophotometry significantly differs depending on the plant species and their anatomical part. All the extracts tested exhibited inhibition of the 2,2-diphenyl-1-picrylhydrazyl free radical in dose-dependent manner. The highest antiradical activity demonstrated the extract from the leaves of Y. filamentosa (IC50 = 25.95 μg/ml) containing the largest amount of phenolic compounds, including flavonoids – 51.3 and 15.5% of the total extractive substances.

No abstract

Melanins are universal biopolymers, the main biological function of which is to protect living organisms from adverse factors. Interest in these dark pigments arises due to the prospects for their use in medicine, cosmeceuticals, bioremediation, bioelectronics, and other fields. In this work, a complex scheme was developed to isolate melanins from the lichen Leptogium furfuraceum (Harm.), which is a symbiotic extremophilic organism. Screening of the conditions for the extraction of melanin, its subsequent precipitation and purification made it possible to isolate three samples of melanin with a total yield of 7.5% of the dry matter of the lichen. It was established that all isolated melanins have a polyaromatic structure, they contain carbohydrates and proteins, the content of which, depending on the conditions for melanin isolation, is 7.3–9.9% and 13.5–32.7%, respectively. Among the isolated melanins, melanin, which is a water-soluble fraction of acid-precipitated melanin, displays the highest antioxidant activity. This melanin, unlike other melanins, is almost fully soluble in distilled water, 95% ethanol, 99% dimethyl sulfoxide, and phosphate buffer (pH 7.4). The differences in solubility, antioxidant activity, and chelating capacity of isolated lichen melanins make it possible to determine potential areas for their practical use.