Том 42, № 7 (2016)

The blends of polylactide with ethyl cellulose and chitosan are obtained in a Brabender mixer under conditions of high temperature shear deformation at different initial ratios of the reagents. The investigation of physicomechanical properties of the compositions has shown that the systems have high rigidity. Polyethylene glycol (PEG) and high-molecular-weight polyolefin polydecene have been added to the compositions in order to improve their elasticity. It has turned out that polydecene scarcely affects the mechanical characteristics, while PEG leads to a noticeable increase in elongation at break. Biodegradability of the compositions is investigated by the mass loss of samples after holding in soil, fungus resistance tests, and the analysis of the film morphology by scanning electron microscopy after holding in soil. It is found that the introduction of the third component (PEG) leads to an increase in biodegradability of the compositions.

We studied the chemical composition of the phenolic complex and the structure of oligomeric lignans in Siberian spruce (Picea obovata Ledeb.). We used the wood of Siberian spruce collected near the city of Irkutsk. The extractives were isolated from ground wood (particle size: 10–15 mm; humidity: 5.9%) by three-stage acetone extraction. The extract was separated by consecutive treatment with the solvents with increasing polarity: hexane, ethyl acetate and n-butanol. The main amount of phenolic compounds (lignans) was concentrated in the ethyl acetate fraction and it was 0.7% in absolutely dry wood (adw).

The ethyl acetate fraction of spruce wood extract was separated by silica gel column; a chloroform-acetone mixture was used as the eluent (the concentration of acetone in the mixture was increased from 0 to 100%). Monomeric lignans (~60–65% of the ethyl acetate fraction of spruce wood extract), oligomeric lignans (~20–25%), and polymer lignans (~12–15%) were isolated.

We also obtained ¹³C nuclear magnetic resonance (NMR) spectra for the main monomeric, oligomeric and polymeric lignan compounds of phenolic complexes. It was found that oligomeric and polymeric fractions contain monomeric lignan units with the butyrolactone cycle, primarily, the fragments with hydroxymatairesinol structure. Oligomeric lignans contain the fragments with a pinoresinol and lariciresinol structure. All the monomeric structural units are characterized by the guaiacyl substitution type of the aromatic cycles.

A preliminary study has been performed on the antiviral and antioxidant activity of the ethyl acetate fraction of acetone extract of Siberian spruce wood. It was found that the lignan complex is active against Coxsackie B4 virus in cell culture and in the pancreatitis model in white mice, reducing the activity of enteroviruses in the cell culture approximately 100 times. The antioxidant activity rate of polyphenol complex of Siberian spruce wood is comparable to that of a known antioxidant dihydroquercetin.

Molecular complexes of triterpene glycosides such as α-hederin (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranoside) and hederasaponin C (hederagenin 3-O-α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-28-O-α-L-rhamnopyranosyl-(1 → 4)-O-β-D-glucopyranosyl-(1 → 6)-O-β-D-glucopyranoside) with β-cyclodextrin were synthesized. The complex formation was studied by FTIR spectroscopy. Toxic properties of the molecular complexes were examined.

Essential oil from the epigeal portion of Artemisia scoparia Waldst. et Kit. collected in different regions of Buryatia and Mongolia has been isolated using steam distillation. The yield of essential oil from the stems and leaves of A. scoparia collected in different regions of Buryatia and in the Selenga aymag of Mongolia ranged from 0.06 to 0.40%, that is, the variation was rather high. The composition of the oil was analyzed using chromatography with mass spectrometric detection on a gas chromatography device Agilent Packard HP 6890 N with a quadrupole mass spectrometric detector HP MSD 5973. The total number of compounds detected exceeded 100. The major components of Artemisia scoparia oil were the following: p-cymene (0.6–15.2%), limonene (0.1–6.3%), α-pinene (0.2–10.1%), β-pinene (0.4–8.9%), trans-β-ocimene (0.3–5.4%), caryophyllene (4.6–13.8%), germacrene D (11.5–40.3%), spathulenol (4.0–11.7%), and caryophyllene oxide (4.3–15.6%). Several chemotypes of essential oil from A. scoparia were identified according to the nature of the major components: 1) oil that contained acetylene hydrocarbons (from plants collected in Gilan, Mazandaran, Kashan, and Tigran provinces of Iran, Tajikistan, and the European part of the CIS); 2) oil that contained monoterpenes and aromatic compounds (from plants collected in the Khorasan province of Iran, India, and South Korea); and 3) oil that contained monoterpenes or aromatic and sesquiterpene compounds (from plants collected in Kazakhstan and Mongolia). The major components of A. scoparia essential oil obtained from Buryatian plants belonged to the classes of mono- and sesquiterpene compounds, and thus the oil can be assigned to the third chemotype characteristic of A. scoparia from geographically close regions.

Carbonization of betulin (betulinol) as an individual carbon precursor was studied in the temperature range of 400–800°C in the presence of KOH. Differential thermal analysis and IR spectroscopy were used to determine the influence of KOH on major structural changes and the chemical composition of betulin, which occur at 400–500°C. It was shown by scanning electron microscopy and BET analysis that KOH promoted the formation of a developed specific surface (S_BET 1350–2100 m²/g) at temperatures of 600–800°C and had the greatest influence on the textural and adsorption properties of the resulting porous carbon adsorbents. It has been found that the formation of microporous carbon materials with a pore size of 1.92 nm and a specific micropore surface area of 1275 m²/g is possible upon the activation of betulin with KOH at 800°C. Betulin may be proposed to control the porosity of the carbon carriers derived from birch wood.

The content of vitamin E in wheat germ oil produced by different manufacturers was determined with a microcalorimetry approach. The maximum amount of tocopherols was shown to be contained in the wheat germ oil produced by mechanical processing of the initial raw material according to Prof. A.B. Vishnyakov’s sparing technology. Eight samples of wheat germ oil produced in different processing cycles by OOO SibTar in the years 2011–2015 were analyzed. The synergistic oil components provided the high content of antioxidants, corresponding to the total content of tocopherols ranging from 240 to 420 mg%, which exceeds the reference data. The key elements for obtaining oil with a high content of vitamins are the use of high quality raw materials and pressing without heating or using any solvents. The content of tocopherols for oils produced from crops of different years was found to vary by 40%, depending mostly on growth and storage conditions of the grain. The content of tocopherols in an oil kind could serve as the oil quality criterion. For example, the values of vitamin E content obtained for two of the wheat germ oil samples tested were three times lower than the reference values, which indicates that these oil samples had been diluted with others kinds of oil.

The object of this study was the extract from the dried pomace of the Amur rowanberry (Sorbus amurensis Koehne) after the juice separation. The content of total polyphenols, lipid composition, and antiradical activity of the extract were studied. The total content of polyphenols proved to be 80 ± 2,5 mg-equivalents of gallic acid per 100 mL of the extract, suggesting the high level of its antiradical activity (29.73 ± 0.23 mmolequivalents of trolox per liter). The lipid part of the extract included three phospholipid fractions and six fractions of neutral lipids. Their content was found to be 13.4 ± 0.14 mg of total lipids/mL. These results pointed to a high biological activity of the extract which could be considered as a promising object for further experimental studies. The Amur rowanberry extract was shown to exhibit a pronounced antioxidant and hepatoprotective activity on the laboratory model of the carbon-tetrachloride-induced hepatitis in rats with endogastric administration at a dose of 100 mg of total polyphenols per kg of body weight. Administration of the extract resulted in a decrease in the content of total lipids, specific liver weight, and the activity of alanine aminotransferase. The level of the reduced glutathione and the activity of antioxidant and lysosomal enzymes were also normalized. The rowanberry extract seemed to be a promising source for the creation of biologically active food supplements with high antioxidant and antiradical activity.

The distinguishing features of rice husk are high strength properties, chemical stability, high ash content, and low nutritional value, which are determined by the composition and structure of this type of raw material. The goal of the study was to determine optimal methods of mechanical treatment for the performance of a solid-phase reaction of silicon dioxide from rice husk with polyphenol compounds. Different regimes of the treatment of plant raw material have been compared. It has been shown that, for the solid-phase reaction of silicon dioxide from plant raw material with polyphenol compounds to occur, both the destruction of the supramolecular complex of silicon dioxide with the lignocellulose matrix, which is accomplished by fine grinding, and the plastic deformation of the silicon dioxide phase with the formation of reaction centers are necessary. These operations can be brought about using grinders with the attrition and shear modes of operation, including roller mills. It is preferable that silicon dioxide is in the composition of plant raw material since the reaction between silicon dioxide and polyphenols with the formation of surface complexes requires the presence of silanol groups. If silicon dioxide is derived from rice husk by conventional methods, most hydroxyl groups are eliminated, which significantly decreases the reactivity.

Ozonation has been considered as a method for the pretreatment of plant biomass to obtain cellulose and monosaccharides. Ozone consumption by aspen wood with various moisture contents has been investigated. We have considered the gradual transformation of the substrate: wood to ozonated wood to cellulose-containing product (CP) to holocelluloze (HC) and to cellulose. Yields of ozonated wood (OW), the (CP), water-soluble ozonation products, HC, and cellulose have been determined. The lignin content in the CP has been estimated. Both HC and cellulose samples have been studied by IR spectroscopy. The degree of polymerization and molecular mass distribution of cellulose obtained from ozonated wood have been determined. It has been shown that wood destruction by ozone is accompanied by degradation of lignin, hemicelluloses, and cellulose.

It has been found that physicochemical properties of cellulose obtained from ozonated wood can be regulated by the variation of the initial moisture content in the substrate. Both molecular ozone and radical species, which are generated in the course of ozone reactions with water present in the substrate structure, participate in wood destruction.