425 research outputs found
Chromatographic analysis and separation of hypericin containing extract of St. john's wort
It has been presented qualitative and quantitative chromatographic analysis of hypericin containing extracts of St. John's Wort which could be used for producing drugs for treating of oncological diseases by the method of photodynamic therapy. The optimal conditions of carrying out of TLC and HPLC analysis of ethanol St. John's Wort extracts have been selected. The chromatographic separation of St. John's Wort extract has been carried out assisted by Diaion HP-20 sorbent. This separation gave the opportunity to enrich the initial extract with hypericins more than in 4 times
Extraction isolation of hypericins from particular kinds of St. john's wort (hypericum perforatum)
The paper deals with development of the effective mode of isolation of hypericins from St. John's Wort including Soxhlet extraction with ethanol as a solvent. In Central Botanical Garden of the NAS of the RB were found out the kinds of St. John's Wort, which contain the largest amounts of hypericins. They may be used as material for producing of phytopreparations and drugs for treating oncological diseases by the method of photodynamic therapy
Electronic absorption spectra of st. john's wort extracts
In this study electronic absorption spectra of John's Wort extracts of different types from the collection of Central Botanical Garden of the Belarusian NAS have been investigated. It has been shown that the character of electronic absorption spectra significantly depends on the nature of herbal material, temperature, polarity of solvents and pH value of medium. The Hypericum perforatumwas found to be the most prospective home herbal material. The optimal conditions of hypericin extraction from John's Wort, including temperature mode and pH value have been established. On the basis of spectral researches it is shown that the greatest extent of hypericin extraction is reached at ethanol and acetone use
Chemical processes causing spoilage of oil and fat products
Article is devoted to the problem of spoilage of oil and fat products in the course of their production, transportation and storage which is caused by the hydrolytic and oxidative processes leading to deterioration of organoleptic properties of fat and oil products and decrease in their nutrition value. Chemical basics of hydrolysis of triacylglycerols are considered in detail. The mechanisms of an acid and base catalysis of hydrolysis of acyl bonds are presented. The mechanisms of lipid peroxidation, antioxidant action of ascorbic acid and ?-tocopherol are shown. Influence of natural vegetable emulsifiers and antioxidant vitamins on quality of margarine and spreads during storage is shown
Natural degradation ways of herbicides of sulfonylurea group
Currently in agriculture much attention is paid to development and use of low-cost and at the same time effective methods of fight against weeds. In this regard, widely purchased sulfonylurea herbicides. The paper presents the general characteristics, mechanism of action, degradation pathways (hydrolysis, photochemical transformation and microbial degradation) of metsulfuron-methyl and tribenuronmethyl. The key role of chromato-mass-spectrometry to establish the mechanisms of destruction these herbicides by soil microorganisms is shown
Engineering of a recombinant fab antibody fragment against cortisol
The paper dwells upon the molecular cloning of genes coding the structure of mouse immunoglobulins, which can specifically bind steroid hormone cortisol. For these purposes primers covering all families of genes, which code the structure ofimmunoglobulins G. Molecular-genetic constructions for effective expression of recombinant antibodies in cells of Escherichia coliwere constructed. Heterologous expression of Fab-fragments was performed. Recombinant protein has been isolated in homogenous state
Cytomorphometric indicators of the gingiva epitheliocytes of patients with ischemic heart disease on the background of taking acetylsalicylic acid
The aim is to study the cytological and morphometric characteristics of gingiva epitheliocytes in patients with IHD who are constantly taking ASA drugs. To determine the dental status, 92 patients aged 40-60 years who are on outpatient treatment of IHD were examined. An in-depth scientific study was conducted and the results of cytomorphometric indicators of the gingiva epitheliocytes of patients with ischemic heart disease, constantly taking acetylsalicylic acid drugs, were presente
Biological potential of jerusalem artichoke as a feedstock for food and pharmaceutical industries
Studies aimed to import pharmaceuticalproducts, as well as to strengthen the food security of the Republic of Belarus, are highly relevant. In this connection an universal culture of Jerusalem artichoke is of interest, the value of which is determined due to the possibility of its use in feed, food and pharmaceutical industries. The paper presents the productivity research of Jerusalem artichoke varieties with different growing seasons, the estimation of mineral composition of tubers, the content of inulin as the most valuable component of mentioned agricultural crops was determined
The natural ways of degradation of pesticides based on 2,4-dichlorophenoxyacetic acid
To increase crop yields by destroying weeds the separate group of pesticides exist, that is called herbicides. Among the herbicides based on chlorphen oxalcanecarboxylic acids products of sodium and ammonium salts, as well as 2,4-dichlorophenoxyacetic acid (2,4-D), are widely used. However, the production and use of pesticides affects the state of the environment and pose a potential risk for public health. In this paper the need to clarify the mechanisms of transformation and degradation of 2,4-D de-rivatives under the action of physical, chemical and biological environmental factors was showed. The preparations based on 2,4-D, registered in the Republic of Belarus is reviewed. The mechanisms of action of these xenobiotics are described, analysis of their toxicity for the environment components is performed. Particular attention is paid to the microbial degradation of pesticides, possible ways of their degradation under the action of microorganisms enzyme systems are described, the factors, that affect
the biotransformation process are an alyzed. It has been shown that th e bacterial degradation of 2,4-D is carried with the formati on of 2,4-dichlorophenol by en zyme 2,4-dihlorphenoxyacetate-α-ketog-lutaratedioxygenase, and further the intermediate degrades with 3,5-dihlorocatechol formation using 2,4-dihlorphenolhydroxylase in two ways: or tho-splitting or peripheral meta-splitting
Complex analysis of flax seeds composition for breeding programs
Single plant selection using complex of seed quality traits requires development and optimization of the methods, which allow qualitative and quantitative analysis applying minimum quantity of seeds. The proposed evaluation scheme of seed composition enables optimal use of seed material for individual plant analysis: oil percentage (Rushkovsky’s extraction method), fatty acid composition (vaporliquid chromatography), protein and ash content (dynamic thermogravimetry), elemental composition (electron probe X-ray fluorescence method). Reproducibility of analytical methods used was assessed by the coefficient of variation, the reproducibility index (ARI) and the convergence of data on seasonal cultivation
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