Sorption Activity of Octadecylsilica Gel-Based Material (Chromabond REF 730611) with Respect to Grosgemin

В работе исследована сорбционная активность сорбента на основе октадецилсиликагеля по отношению к гроссгемину. Построены динамические кривые сорбции в диапазоне концентраций 0,5–2,5×10 –3мг/мл гроссгемина в ацетонитрильных растворах. Графически определены сорбционные характеристики: объём до «проскока», равновесный объём и объём удерживания. На основании полученных данных рассчитана динамическая ёмкость сорбента. Установлено, что варьирование концентрации ацетонитрила (MeCN) оказывает влияние на сорбционные характеристики сорбента в динамическом режиме: при увеличении концентрации объем до «проскока», объём удержания значительно уменьшаются. Так, динамическая ёмкость снижается: от 1,39±0,02 при 10 % MeCN до 0,10±0,01мг/г при 50 % MeCN. Построены кинетические кривые сорбции и показано, что максимальная адсорбция гроссгемина достигается спустя 4 минуты после контакта с октадецилсиликагелем в среде 20 % раствора ацетонитрила. Определен механизм полимолекулярной адсорбции гроссгемина по теории Брауна- Эммета-Теллера на поверхности октадецилсиликагеля. Полученные в результате работы значения сорбционной ёмкости от 0,0017 до 0,0252 мг/г свидетельствуют об эффективности использования октадецилсиликагеля для дальнейшего твердофазного концентрирования гроссгемина как этапа подготовки проб экстрактов растительного сырья василька шероховатого для хроматографического анализаThe sorption activity of octadecylsilica gel-based sorbent towards grosgemin has been investigated. Dynamic sorption curves in the concentration range of 0.5–2.5×10–3mg/mL grosgemin in acetonitrile solutions were plotted. The sorption characteristics: volume before “slip”, equilibrium volume and retention volume were determined graphically. On the basis of the obtained data the dynamic capacity of the sorbent was calculated. It was found that varying the concentration of acetonitrile (MeCN) affects the sorption characteristics of the sorbent in the dynamic regime: with increasing concentration, the “volume to slip” and the retention volume decrease significantly. Thus, the dynamic capacity decreases: from 1.39±0.02 at 10 % MeCN to 0.10±0.01mg/g at 50 % MeCN. Kinetic curves of sorption were constructed and it was shown that the maximum adsorption of grosgemin is reached 4 minutes after contact with octadecylsilica gel in the medium of 20 % acetonitrile solution. The mechanism of polymolecular adsorption of grosgemin according to the Brown-Emmett-Teller theory on the surface of octadecylsilica gel was determined. The values of sorption capacity from 0.0017 to 0.0252 mg/g obtained as a result of the work testify to the efficiency of using octadecylsilica gel for further solid- phase concentration of grosgemin as a stage of preparation of samples of extracts of plant raw materials of cornflower for chromatographic analysi

Quantitative Structure-Activity Relationship, Ontology-Based Model of the Antioxidant and Cell Protective Activity of Peat Humic Acids

Peat humic acids are well known for their wide range of biological effects which can be attributed to the complex chemical structure of naturally occurring humic substances. One of the promising tools is an ontology-based quantitative analysis of the relationship between physical and chemical parameters describing a chemical structure of peat humic acids and their biological activity. This article demonstrates the feasibility of such an approach to estimate the antioxidant and cell protective properties of the peat humic acids. The structural parameters of the peat humic acids were studied by electronic, fluorescence, infrared, 13C-NMR spectroscopy, titrimetric analysis, elemental C,H,N, and O- analysis, and gel chromatography. Antioxidant and antiradical activities were assessed by physicochemical methods of analysis: electronic paramagnetic resonance, cathodic voltammetry, ABTS•+ scavenging, assay of DPPH radical-scavenging activity, assay of superoxide radical-scavenging activity, iron chelating activity, and scavenging of hydroxyl radicals. Cytoprotective activity was evaluated by the neutral red-based cytotoxicity test in 3T3-L1 cell culture in a wide range of concentrations. Assessment of intracellular ROS production was carried out using a 2,7-dichlorodihydrofluoresceindiacetate (DCFDA) fluorescent probe. Intracellular ROS production was induced using two common prooxidants (tert-butyl hydroperoxide, Fe2+ ions). We suggested an ontology-based model for the antioxidant and cytoprotective activity of humic acids based on experimental data and numerical models. This model establishes the way to further research on the biological effects of humic acids and provides a useful tool for numerical simulation of these effects. Remarkable antioxidant and cell protective activity of humic acids makes them a promising natural source of new pharmaceutical substances that feature a wide range of biological effects

Immunomodulatory Activity of Polysaccharides Isolated from <i>Saussurea salicifolia</i> L. and <i>Saussurea frolovii</i> Ledeb

The genus Saussurea has been used in the preparation of therapies for a number of medical problems, yet not much is known about the therapeutic high-molecular-weight compounds present in extracts from these plants. Since polysaccharides are important in immune modulation, we investigated the chemical composition and immunomodulatory activity of Saussurea salicifolia L. and Saussurea frolovii Ledeb polysaccharides. Water-soluble polysaccharides from the aerial parts of these plants were extracted using water at pHs of 2 and 6 and subsequently precipitated in ethanol to obtain fractions SSP2 and SSP6 from S. salicifolia and fractions SSF2 and SSF6 from S. frolovii. The molecular weights of fractions SSP2, SSP6, SFP2, and SFP6 were estimated to be 143.7, 113.2, 75.3, and 64.3 kDa, respectively. The polysaccharides from S. frolovii contained xylose (67.1–71.7%) and glucose (28.3–32.9%), whereas the polysaccharides from S. frolovii contained xylose (63.1–76.7%), glucose (11.8–19.2%), galactose (4.7–8.3%), and rhamnose (6.8–9.4%). Fractions SSP2, SSP6, and SFP2 stimulated nitric oxide (NO) production by murine macrophages, and NO production induced by SSP2, SSP6, and SFP2 was not inhibited by polymyxin B treatment of the fractions, whereaspolymyxin B treatment diminished the effects of SFP6, suggesting that SFP6 could contain lipopolysaccharide (LPS). The LPS-free fractions SSP2, SSP6, and SFP2 had potent immunomodulatory activity, induced NO production, and activated transcription factors NF-κB/AP-1 in human monocytic THP-1 cells and cytokine production by human MonoMac-6 monocytic cells, including interleukin (IL)-1α, IL-1β, IL-6, granulocyte macrophage colony-stimulating factor (GM-CSF), interferon-γ, monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor (TNF). These data suggest that at least part of the beneficial therapeutic effects reported for water extracts of the Saussurea species are due to the modulation of leukocyte functions by polysaccharides