Carbohydrates ofSymphytum asperum

It has been shown that the carbohydrates ofSymphytum asperum L. — a promising fodder plant — include water-soluble polysaccharides, pectin substances, protopectin, hemicelluloses, a glucomannan, and cellulose. The quantitative amounts of the polysaccharide fractions in the raw material have been established and their characteristics are given. The protopectins of the leaves and stems ofSymphytum asperum L. have been characterized. Their macromolecules are based on a fragment constructed of D-galacturonic acid residues linked by -glycosidic bonds.M. V. Lomonosov Odessa Technological Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 15–20, January–February, 1984.     

Interaction of pectin substances with copper,mercury, zinc,and cadmium salts

The interaction of the sage, mint, apple, and ginseng pectins, isolated from tissue culture wastes and purified with copper, mercury, zinc, and cadmium salts, has been studied by the amperometric method with two metal indicator electrodes. The optimum conditions of titration have been determined: pH 3.5–5.0; concentration of pectin substances 5·10^–5-1·10^–3 g/ml of solution. It has been established by graphical and mathematical methods that the interaction is accompanied by the formation of compounds with a ratio of the carboxy groups of pectins to the metal cation of two. The IR spectra of sage pectin and of copper and mercury pectinates are given.M. V. Frunze, Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 171–175, March–April, 1988.     

Trends in the science and applications of pectins

The literature on the chemistry and application of pectins is reviewed. The principal themes are the search for nontraditional sources of pectins with novel structural elements and the deeper understanding of the structure and physicochemical properties of well studied pectins from traditional sources (apple, beet, citrus). Custom preparation of pectins with a desired set of properties that have practical application in medicine, biology and the food industry has been demonstrated. Chemical modification of pectins is a promising trend.Institute of Polymer Chemistry and Physics, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (998-71)-144-26-61. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–11, January–February, 2000.     

Modification of the solubility of benzimidazole drugs on mechanical treatment with pectins

The change in the solubility of some benzimidazole drugs on their mechanical treatment with pectins has been investigated. It has been shown that the rate of desorption of a drug depends both on its structure and on the nature of the pectin.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent (IKhRV AN RUz), fax (3712) 89 1475. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 556–561, July–August, 1995. Original article submitted November 14, 1994.     

A study of the pectins of wild apples

Pectins have been isolated from five species of wild apples and have been characterized. They contain galacturonic acid, galactose, glucose, and arabinose residues. The titrimetric indices of the substances isolated have been determined. It has been shown by IR spectroscopy the pectins isolated are extracted partially in the form of pectic acids.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbekistan Republic, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 355–357, May–June, 1993.     

Chemical investigation of biomass of a culture of ginseng cells III. Polysaccharides of a callus culture of ginseng

A water-soluble polysaccharide fraction has been isolated from a callus culture of ginseng with a yield of 16–20%. It has been shown that it included starch a and acidic polysaccharides — arabinogalactans and a xyloglucan.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok, All-Union Scientific Research Institute of Biochemical Machinery Design, USSR Ministry of the Medical Industry, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 771–772, November–December, 1989.     

Polysaccharides from the wastes of vegetable and melon-type crops

The water-soluble polysaccharides and pectin substances from the wastes of vegetable and melon-type crops have been studied and their monosaccharide compositions have been determined. High- and low-methoxyl pectins have been isolated, and the physicochemical characteristics are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 597–600, September–October, 1994.     

Structure and properties of apple pectin

Some molecular and structural features of apple pectins obtained by various methods have been revealed through an analysis of the results of physical and physicochemical investigations.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 40 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 792–796, November–December, 1997.     

Polydispersity of pectins and some physicochemical properties of their solutions

Pectin solutions obtained in the presence of HNO₃, HCl, H₂SO₄, and H₃PO₄ have been studied by viscometry, turbidity spectra, and ultracentrifugation. Cotton pectin extracts with phosphoric acid proved to be the most unstable. The molecular masses of pectins obtained from various materials (apple, lemon, and grape press residues, beet pulp, and cotton boll valves) ranged between 14,000 and 37,000. The polydispersity of the pectins isolated was studied.Tashkent State Technical University, fax (3712) 29 48 36. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 349–353, May–June, 1998.     

Large-Scale Purification of Water-Soluble Polysaccharides from Flaxseed Mucilage, and Isolation of a New Anionic Polymer

Summary Viscous flaxseed mucilage has previously been described as a mixture of two polysaccharides (acidic and neutral). In this study, we have shown that a combination of ion exchange and size exclusion chromatography enables purification of three distinct polysaccharides. Molecular weight (Mw) analysis, performed by size-exclusion chromatography on line with a multi-angle laser light-scattering detector, revealed that the main polysaccharide (75%) was a neutral polymer with a Mw of approximately 1.2 × 10⁶ g mol^–1. The two others were acidic polysaccharides denoted AF₁ (3.75%, 6.5 × 10⁵ g mol^–1) and AF₂ (21.25%, 1.7 × 10⁴ g mol^–1).Presented at: International Symposium on Separation and Characterization of Natural and Synthetic Macromolecules, Amsterdam, The Netherlands, February 5–7, 2003     

Lipids and lipopolysaccharides of the genusFlavobacterium

The fatty acid compositions of the free lipids of three strains and the monosaccharide compositions of the lipopolysaccharides of four strains of new species of microorganisms of the genusFlavobacterium have been studied. The acidic nature of the polysaccharides of the LPSs of the microorganisms studied has been shown.Pacific Ocean Institute of Bioorganic Chemistry of the Far Eastern Scientific Center of the USSR Academy of Sciences, Vladivostok, and Institute of Microbiology of the USSR Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 564–567, September–October, 1986.     

Protein-lipid complexes of cotton kernels and the products of their processing

The composition and lipid content of the lipoprotein complexes of cotton kernels (I), meal (II), and isolate (III) have been investigated. It has been shown that with the aid of an acidic alcohol-containing extractant it is possible to isolate up to 99% of the strongly bound lipids (SBLs) of their total mass. In the composition of the strongly bound lipids (I–III) have been found neutral lipids comparable with the free lipids of the kernel; of polar lipids, glycolipids were present. It was found that an acid extractant extracts polyphenolic compounds together with the SBLs.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 466–472, July–August, 1990.     

Characteristics of the water-soluble polysaccharides of the leaves ofSilphium perfoliatum

The characteristics of the water-soluble complex of the leaves ofSilphium perfoliatum are given. The presence in them of acidic components of the type of pectic substances containing considerable amounts of compounds of protein nature has been shown. It has proved to be possible to separate the latter from the carbohydrate component by fractionation on DEAE-cellulose.M. V. Lomonosov Odessa Technological Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 771–774, November–December, 1979.     

Methanol conversion on high-silica zeolites with different alumosilicate modules and prepared in different ways

High-silica zeolites in the H-form that differ in the SiO₂/Al₂O₃ ratio and the method of synthesis, have similar acidity spectra but different distributions of the acidic centers with respect to strength. A symbatic change in the concentration of the strongly acidic centers and of the degree of conversion of methanol has been observed, as well as a change in selectivity for C₂–C₄ aliphatic and aromatic hydrocarbons. It has been established that the stages of dehydration of methanol and dimethyl ether, and of aromatization and alkylation occur on strongly acidic centers of high-silica zeolites, and polymerization reactions on weakly acidic centers.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 3, pp. 380–383, May–June, 1987.     

Carbohydrates and lipids ofBrassica oleracea

Lipids and polysaccharides have been obtained from the leaves ofBrassica oleracea. The qualitative and quantitative compositions of the lipid complex have been studied. The fatty acid compositions of the total neutral lipids and of the phospho- and glycolipids have been determined. The carbohydrate complex of cabbage includes water-soluble polysaccharides, low-methoxyl pectins, hemicelluloses, and free monosugars. The polypeptides have been characterized by their mannoside compositions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 612–615, September–October, 1994.     

Oxoacidic properties of some Ba-based chloride melts

Solubilities of CdO and ZnO in molten BaCl₂–KCl–NaCl (0.43:0.29:0.28) and BaCl₂–KCl (0.26:0.74) at 700°C have been determined by the potentiometric titration technique. Oxobasicity indices of these melts are estimated as 2.01 and 1.83, respectively. A correlation between oxobasicity indices and the content of most acidic cation (Ba²⁺) is shown to exist.     

The preparation of astatine labelled tyrosine using an electrophilic reaction

Carrier-free astatotyrosine has been synthesized using an electrophilic reaction in acidic media. Temperature of 150–160°C and reaction time of 20–30 min were chosen as optimal conditions for the synthesis of astatotyrosine. Under the selected conditions the yield was about 90%.     

Direct measurements of interfacial interactions between pectin and κ-casein and implications for the stabilisation of calcium-free casein micelle mimics

Using Surface Plasmon Resonance (SPR) it has been shown that the fine structure of the anionic polysaccharide pectin strongly influences its interfacial interaction with a κ-casein layer coated onto a gold surface (via a dextran linker) in the pH range 3.5–6.8, with the highest SPR signal being observed for pectin with the lowest charge density tested (a degree of methylesterification (DM) around 90%).Furthermore, the Brownian motions of κ-casein coated polystyrene beads (used to provide calcium-free ‘model casein micelles’) were studied in pectin solutions using Diffusing Wave Spectroscopy (DWS) and microscopy, and were compared with measurements made on naked beads. At every pH value studied (with the exception of 3.5), bridging of the protein-covered probe particles was observed for pectins of both DM 28 and DM 78. However, no aggregated complexes were found in these model casein micelle systems when pectin of an unusually high DM was used (90%).It was hypothesised that having a limited number of binding regions of spatially limited extent maximises the number of chains binding to the protein layer (as found with the SPR measurement), encourages the formation of loops and trains, and additionally limits the potential for destabilisation via bridging.     

Synthesis and steric structure of 4-arylaminohexahydropyrimidine-2-thiones

Reaction of 4-hydroxy- and 4methoxyhexahydropyrirnidine-2-thiones and 6-methyl-1, 2, 3, 6-tetra-hydropyrimidine-2-thione with primary amines occurs readily in the presence of acidic or basic catalysts to give 4-arylaminohexahydropyrimidine-2-thiones both regio- and stereoselectively. It was shown that reaction stereoselectivity depends on the structure of the starting materials and on the reaction conditions. The steric structures of the products synthesized has been studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1093–1104, August, 1994.