Some kinetic features of the hydrolysis of protopectin

Some features of the kinetics of the hydrolysis of apple protopectin have been studied on the basis of an analysis of monosaccharide residues of the pectin substances and determinations of characteristic viscosity. It has been shown that the fine regulation of the physicochemical parameters of the hydrolysis of protopectin leads to the formation of pectin substances with different properties.Institute of Chemistry, Republic of Tadzhikistan, Dushanbe. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 787–793, November–December, 1994.     

Pectin substances of the stems and fruit husks of Fagopyrum saggittatum

The polysaccharides were extracted from the raw material with a 0.5% solution of ammonium oxalate. They were investigated by various methods: partial and complete acid hydrolysis, fractionation on a column of DEAE-cellulose, IR spectroscopy, enzymatic hydrolysis, etc. It was shown that the protopectin of the stems and fruit hulls of common buckwheat are similar to the pectin substances of other higher plants and are characterized by a low degree of esterification.     

Pectin substances of the stems and fruit husks of Fagopyrum saggittatum

The polysaccharides were extracted from the raw material with a 0.5% solution of ammonium oxalate. They were investigated by various methods: partial and complete acid hydrolysis, fractionation on a column of DEAE-cellulose, IR spectroscopy, enzymatic hydrolysis, etc. It was shown that the protopectin of the stems and fruit hulls of common buckwheat are similar to the pectin substances of other higher plants and are characterized by a low degree of esterification.M. V. Lomonosov Odessa Technological Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 499–501, July–August, 1987.     

Physicochemical Principles of Plant-Cell Protopectin Decomposition by Acid Catalysts

Research results published in 1990-2002 on acid hydrolysis of apple protopectin and sunflower calathides were reviewed. Decomposition products and the biological activity of the resulting pectinic substances were identified.     

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.     

Carbohydrates of cultivated varieties ofAlthea rosea

The polysaccharides of three cultivated varieties ofAlthea rosea have been investigated. The amounts of water-soluble polysaccharides and pectin substances in various organs of the plant have been determined. It has been shown that the maximum amount of water-soluble polysaccharides and pectin substances is present in the flowers. Their monosaccharide compositions have been studied. The physicochemical characteristics of the pectin substances are given.     

Polysaccharides ofEremurus. XXI. Pectin substances of the leaves ofEremurus regelii

The pectin substances have been isolated fromEremurus regelii Vved., their qualitative and quantitative monosaccharide compositions have been determined, and their physicochemical properties have been studied. The partial hydrolysis of the pectin gave a galacturonan. On the basis of the results of periodate-nitric acid oxidation, enzymatic hydrolysis, and methylation it has been shown that in the galacturoman the galacturonic acid residues are linked by -(1 4)-glycosidic bonds.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 172–174, March–April, 1985.     

Carbohydrate complex of the fruit of Chaenomeles maulei

The carbohydrate complex of the fruit ofChaenomeles maulei contains more than 70% of water-soluble sugars, including sucrose, arabinose, galactose, fructose, and glucose. The bulk of the carbohydrate is represented by water-soluble pectin, and protopectin, hemicellulose, and cellulose. The monomeric compositions of all the fractions of carbohydrates and the ratio between the reducing and inverted sugars have been studied.M. V. Lomonosov Odessa Technological Institute of the Food Industry. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 460–463, July–August, 1990.     

Modification of the titrimetric method of analyzing pectin substances

A potentiometric variant of the titrimetric method of analyzing pectin substances has been developed which is distinguished by adequate accuracy and good reproducibility. The modified method has been tested on methyl (methyl 2,3-di-O-methyl-α,β-galactopyranosid)uronate and has been used for determining the free (K_f) and esterified (K_e) carboxy groups of the pectin substances of mint. The methods of isolating, purifying, and fractionating the pectin substances and determining their K_f and K_e values are given. Formulas are presented for calculating the percentage values of K_f and K_e.     

Carbohydrates of cultivated varieties ofAlthea rosea

The polysaccharides of three cultivated varieties ofAlthea rosea have been investigated. The amounts of water-soluble polysaccharides and pectin substances in various organs of the plant have been determined. It has been shown that the maximum amount of water-soluble polysaccharides and pectin substances is present in the flowers. Their monosaccharide compositions have been studied. The physicochemical characteristics of the pectin substances are given.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. A. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan. Tashkent. Institute of Botany, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedineii, No. 5, pp. 643–646, September–October, 1993.     

Technology of the production of pectin substances from the fruit ofSorbus aucuparia

The optimum conditions for the isolation of pectin substances from a pulp of the European mountain ash freed from lipophilic substances have been studied, and the characteristics of the substances are given.     

Studies on the Zymogram Method for the Detection of Pectinolytic Activities Using CTAB

Zymogram analysis is a useful tool for the identification of several enzymes. The present study was undertaken to investigate the efficiency gains from the characterization of pectic enzymes on zymograms by staining of pectin-agarose overlays using cetyl trimethyl ammonium bromide also known as cetrimide or CTAB. The method is based on the fact that the enzymatic hydrolysis of the pectic substrates included in the agarose matrix gel inhibited their precipitation by CTAB, leading to the appearance of cleared zones in front of the pectin hydrolases and lyases. Conversely, esterases led to the increase of pectin precipitation. Fungal pectinolytic enzymes were separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subjected to the zymogram detection technique, using two pectin substances, namely citrus pectin and polygalacturonic acid. Overall, the findings presented in the current study indicate that several elements (ions, salts, pH, temperature, chelators, and reducing agents) may significantly affect the results of zymogram analysis and can, therefore, be employed to enhance the discriminatory and operational potential of the analysis in terms of accurate discrimination between several pectinolytic activities involved and effective implementation of the purification procedures required in the process.     

Polysaccharides from the wastes of some fruit and berry,vegetable, and technical crops

The fractional isolation of water-soluble polysaccharides and pectin substances has been carried out from the wastes of fruit and berry and vegetable crops: apples, quinces, grapes, and tomatoes, and also the valves of cotton bolls. The qualitative and quantitative monosaccharide compositions of the carbohydrates isolated have been determined, and the characteristics of the pectin substances are given.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 21–24, January–February, 1985.     

Modification of the titrimetric method of analyzing pectin substances

A potentiometric variant of the titrimetric method of analyzing pectin substances has been developed which is distinguished by adequate accuracy and good reproducibility. The modified method has been tested on methyl (methyl 2,3-di-O-methyl-,-galactopyranosid)uronate and has been used for determining the free (K_f) and esterified (K_e) carboxy groups of the pectin substances of mint. The methods of isolating, purifying, and fractionating the pectin substances and determining their K_f and K_e values are given. Formulas are presented for calculating the percentage values of K_f and K_e.M. V. Frunze Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 428–431, July–August, 1984.     

Technology of the production of pectin substances from the fruit ofSorbus aucuparia

The optimum conditions for the isolation of pectin substances from a pulp of the European mountain ash freed from lipophilic substances have been studied, and the characteristics of the substances are given.Academician I. P. Pavlov Ryazan' Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 777–780, November–December, 1979.     

A multipotential hydrolytic reactor using the yeast strainKluyveromyces marxianus

In previous publications, we described the continuous production of D-fructose from enzymatic hydrolysis of inulin with immobilized permeabiliized cells ofKluyveromyces marxianus and the increase of productivity obtained by using a mutant selected by NTG action on the wild-type strain. By improving reactor performance, it has been possible to reach 2000 g/L/d of liberated sugar from an inulin solution with the mutant strain.

In addition, it has been shown that the KF 28 mutant was an invertase and pectinase hyperproducer. These enzymatic activities are also secreted by the speciesKluyveromyces marxianus. Therefore, we investigated the possibility of using immobilized cells of this yeast as a multipotential hydrolysis reactor. A sucrose hydrolysis reactor and a pectin hydrolysis reactor were set up. It is shown here that the majority of the optimized parameters from the inulin hydrolysis reactor can be transported directly to the other reactors. However, some parameters have to be adapted, especially for pectin hydrolysis.

     

Plant pectin substances. Methods of isolating pectin substances

Information is given on methods of isolating plant pectin substances from various raw-material sources, and the conditions for obtaining high-quality pectin are discussed.     

Effect of Supporting Electrolyte on Hydrolysis of Sunflower Protopectin

The effect of supporting electrolyte on the kinetics of hydrolysis of protopectin (PP) from sunflower heads is studied. The yield of principal decomposition products is determined. The kinetic parameters of the reaction are calculated. Increasing the concentration of supporting electrolyte by adding NaCl to the reaction mixture increases the rate of PP decomposition by 2.5 times and the yield of principal reaction product, a pectinic substance, by more than 20% and decreases the amount of microgel to undetectable quantities and the oligosaccharide content in solution.     

Electrochemical extraction of alkaloids of the tropane group from plant raw material

Summary 1. In a study of the carbohydrates ofEremurus regeli Vved., according to the period of development of the plant, it has been found that in the leaves the maximum amount of pectin substances is present in the period of the ripening of the seeds. In the tuber roots, water-soluble polysaccharides form the main component and they are present in maximum amount after the withering of the epigeal part.2. A preliminary investigation of the pectin substances from the leaves has shown that they belong to the heteropolysaccharides consisting of galacturonic acid and the neutral monosaccharides xylose, rhamnose, arabinose, and galactose.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 429–432, July–August, 1974.     

Carbohydrates ofMelo zard pang

Alcohol-soluble carbohydrates, water-soluble polysaccharides, and pectin substances have been isolated from melon juice pulp. The substances isolated have been studied by IR spectroscopy.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (998 71) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 442–444, July–August, 1999.