A study of pectic polysaccharides in musts from various mature grapes grown in the Pech Rouge experimental vineyards

Soluble pectic polysaccharides were isolated from musts of seven mature grape cultivars by a 4-step procedure: pressing of the berries, denaturation of soluble proteins from must by emulsification with chloroform, elimination of diffusable molecules by extensive dialysis and finally discoloration onto Polyamide CC6. The polysaccharides were mainly constituted of arabinose, galactose and galacturonic acid, and their concentration in musts varied from 133 to 593 mg/l. The arabinose/galactose molar ratio was stable (0.91-1.04) for all cultivars, but one, Cinsaut (0.68). Methylation analyses showed that the polysaccharides from musts are a complex mixture of type II arabinogalactans, arabinans and rhamnogalacturonans. Similarities were observed in the relative distributions of galactose and arabinose structural features except for the Cinsaut and Grenache cultivars in which higher proportions of 3- and 3,6-linked galactose were found.     

Polysaccharides of cell cultures of Silene vulgaris

Callus and suspension cultures of campion (Silene vulgaris) produced pectin polysaccharides, similar in structure to the polysaccharides of intact plants. The major components of the pectins were D-galacturonic acid, galactose, arabinose, and rhamnose residues. The maximum content of pectins was found in callus. The monosaccharide composition of arabinogalactans isolated from cells and a culture medium of callus cultures were similar, with the ratio between arabinose and galactose of 1: (2.3-6.5) being retained. The arabinogalactans from the cells and culture medium of the suspension cultures also had a similar structure, and the arabinose to galactose ratio was 1: (1.5-1.8). In contrast to the callus cultures, the suspension cultures produced arabinogalactans with an increased content of arabinose residues and a decreased content of galactose residues. The greatest content of arabinogalactan was detected in the culture medium of the suspension cultures.     

Effect of arsanilic acid on anaerobic methanogenic process: Kinetics,inhibition and biotransformation analysis

Arsanilic acid (4-aminophenylarsonic acid) is widely used in the poultry and animal industries as a feed additive in the diets. Nearly all the added arsanilic acid is excreted unchanged in manure resulting in the risk of arsenic contamination. In this study, the effects of arsanilic acid on the kinetics, inhibition of methanogenic process and its biotransformation were investigated. The methane yield was not affected by arsanilic acid loading at concentration <0.46 mM, while the methane production was completely inhibited at concentration of 0.92 mM. The IC₅₀ of arsanilic acid in this study was 0.47 mM. After 115 days of incubation, 37–59% of the added arsanilic acid was degraded. The species analysis indicated that at lower initial arsanilic acid concentration, the soluble inorganic arsenic mainly existed in the species of arsenate (As(V)), while at higher initial arsanilic acid concentration (>0.460 mM), the soluble inorganic arsenic mainly existed in the species of arsenite (As(III)), which explains why higher arsanilic acid concentration has severe inhibition to methanogens.     

Assessing eco-toxicological effects of industrial 2,4-D acid iso-octylester herbicide on rat pancreas and liver

Abstract

We studied the eco-toxic and carcinogenic effects of a commonly used 2,4-D acid iso-octylester herbicide on rat liver and pancreas. The rats in Group 1 were fed a standard feed and the rats in Group 2 were fed with standard feed to which was added 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks. Azaserine, 30 mg/kg/body weight, was injected into rats of Groups 3 and 4 to investigate the effects of 2,4-D acid iso-octylester on the development of neoplasms. After feeding the rats with neoplasms in Group 4 with food including 200 mg/kg/day 2,4-D acid iso-octylester for 16 weeks, an autopsy was carried out on all animals. We found that 2,4-D acid iso-octylester caused the formation of atypical cell foci (ACF) in the pancreata and livers of rats. ACF that were formed experimentally by exposure to azaserine had increased diameter, volume and number of atypical cell foci/mm² and mm³ after exposure to 2,4-D acid iso-octylester. Our observations indicated that this herbicide potentially is a cancer initiator.     

Polysaccharides of cell cultures of <Emphasis Type="Italic">Silene vulgaris</Emphasis>

Callus and suspension cultures of campion (Silene vulgaris) produced pectin polysaccharides, similar in structure to the polysaccharides of intact plants. The major components of the pectins were D-galacturonic acid, galactose, arabinose, and rhamnose residues. The maximum content of pectins was found in callus. The monosaccharide composition of arabinogalactans isolated from cells and a culture medium of callus cultures were similar, with the ratio between arabinose and galactose of 1: (2.3–6.5) being retained. The arabinogalactans from the cells and culture medium of the suspension cultures also had a similar structure, and the arabinose to galactose ratio was 1: (1.5–1.8). In contrast to the callus cultures, the suspension cultures produced arabinogalactans with an increased content of arabinose residues and a decreased content of galactose residues. The greatest content of arabinogalactan was detected in the culture medium of the suspension cultures.     

Arsenic Uptake and Accumulation in Rice (Oryza sativa L.) at Different Growth Stages following Soil Incorporation of Roxarsone and Arsanilic Acid

Experiments were conducted with rice (Oryza sativa L.) by adding 0, 10, 20, 30, 40, 50 mg kg^-1 of arsenic (As) to soil (with roxarsone and arsanilic acid, presented as As concentrations) at a field with an isolation chamber. The aims were to evaluate the effects of As- (roxarsone or arsanilic acid) contaminated soil on rice agronomic parameters and uptake of As in different plant parts of the rice plant. The results showed that As (roxarsone or arsanilic acid) could significantly reduce plant height, effective tiller number, straw weight and grain yield (P < 0.01). As concentrations in different parts of the plant varied with the growth stages, and behaved similarly. At the maturing stage, the level in different parts peaked in all treatments, with tissue As concentrations showing the pattern: root > leaf > stem > husk > grain. In addition, at the mature stage, the As concentrations in different parts of the rice plant increased with increasing concentrations of roxarsone and arsanilic acid. The highest concentration of As found in grain was 0.82 mg kg^-1, which did not exceed the statutory permissible limit for rice grain (1.0 mg As kg^-1), and in the leaf and stem it was approximately 6.0 mg kg^-1, which was significantly higher than that in the controls. The results showed that rice could accumulate As from contaminated soil (roxarsone or arsanilic acid), which may be transferred to human beings via the food chain.     

Isolation of Polysaccharides from the Callus Culture of Lemna minor L.

Two fractions that included acid arabinogalactan and pectin were extracted from the callus culture of duckweed plants (Lemna minorL.) with water and ammonium oxalate. Residues of galactose and arabinose (ratio, (2.0–2.5) : 1) were the major constituents of acid arabinogalactan. The pectin fraction contained primarily residues of glycuronic acids, galactose, and arabinose. The percentages of arabinogalactan and pectin were similar. The yield of polysaccharide fractions did not depend on the method used for their isolation. Extraction with water, treatment of the biomass with aqueous formalin and dilute hydrochloric acid, and extraction with aqueous ammonium oxalate allowed us to obtain the pectin polysaccharide with the highest purity.     

Structure of the arabinogalactan from zea shoots

The structure of the arabinogalactan obtained from the buffer-homogenate of Zea mays L. (hybrid B73 × Mo17) shoots has been studied. The purified polysaccharide was investigated by methylation analysis before and after controlled acid hydrolysis. Arabinogalactan-1 consists of arabinose, galactose, xylose, uronic acid, and glucose in the molar ratio of 37.1:55.8:3.0:4.1:trace, and arabinogalactan-2 consists of the same sugars in the ratio of 35.4:53.9:1.6:9.2:trace. A trace of protein was detected in arabinogalactan-1 and about 0.2% was present in 2. About 20% of the galactose residues in arabinogalactan-1 constitute a (1 → 3)-linked galactan chain and approximately 60% constitute a (1 → 6)-linked galactan sequence. About 15% of the galactose residues in arabinogalactan-1 are substituted by galactose in the 3- and 6-positions, thereby constituting branch points of the galactan framework. The remainder (5%) of the galactose residues in arabinogalactan-1 are located at nonreducing terminal positions. About 85% of the (1 → 6)-galactosyl sequence is substituted, mostly by single arabinose residues. Nonreducing terminal glucuronic acid is attached to C-6 of galactose residues. The basic structure of arabinogalactan-2 is similar to that of arabinogalactan-1.     

Structural features of the sulphated polysaccharide from a green seaweed, Cladophora socialis.

A sulphated heteropolysaccharide, [alpha]27D + 59.9 degrees, has been isolated from a green seaweed, Cladophora socialis, by extraction with dilute acid and purified by fractional precipitation. The polymer is composed of galactose (58.3%), arabinose (31.8%), xylose (10.6%) and sulphate (16.9%). The results of methylation analysis, periodate oxidation and partial acid hydrolysis studies indicate that the polymer is a branched one and is composed of 1,3-linked galactose and 1,4-linked arabinose units. Xylose is present at the non-reducing end position of the branches. Both arabinose and galactose carry branches. Desulphation and subsequent analysis of the polymer show that some of the arabinose units carry sulphate groups at C-3 and some of the galactose units carry the sulphate groups at C-4 and some at C-4 and C-6 as well.     

Isolation of polysaccharides from callus culture of Lemna minor L

Two fractions that included acid arabinogalactan and pectin were extracted from the callus culture of duckweed plants (Lemna minor L.) with water and ammonium oxalate. Residues of galactose and arabinose in the 2.0-2.5:1 ratio were the major constituents of acid arabinogalactan. The pectin fraction contained primarily residues of glucuronic acids, galactose, and arabinose. The percentage of arabinogalactan and pectin was similar. The yield of polysaccharide fractions did not depend on the method for their isolation. Extraction with water, treatment of the biomass with an aqueous solution of formalin and diluted hydrochloric acid, and extraction with an aqueous solution of ammonium oxalate allowed us to obtain the highest-purity pectin polysaccharide.     

Determination of fermentable carbohydrate from the upper gastrointestinal tract by using colectomized rats.

The primary aim of this study was to characterize the carbohydrate that would be supplied to the colon for fermentation under physiological conditions. Colectomized rats were fed fiber-free diets or diets containing 5% (wt/wt) gum arabic. Four (fucose, galactose, glucosamine, and galactosamine) of 11 analyzed sugars accounted for 77% of the total sugar in ileal excreta from colectomized rats fed fiber-free diets. The three sugars in gum arabic, rhamnose, arabinose, and galactose, accounted for 84% of the total sugars in gum arabic ileal excreta. Comparisons of the sugar compositions of the ileal excreta, the water-soluble fractions of the excreta, and three gel filtration fractions of the water-soluble material with those of the water-soluble fraction of rat mucosa, the acetone-soluble fraction of pancreas, and pancreatin suggested that the major source of endogenous carbohydrate is mucin. Gum arabic increased the daily excretion of the four mucin-derived sugars (fucose, galactose, glucosamine, and galactosamine) by the colectomized rats from 473 mumol per day to 634 mumol per day. We conclude that mucin is the major endogenous carbohydrate excreted from the upper gut and that gum arabic increases the amount of this endogenous carbohydrate.     

Determination of fermentable carbohydrate from the upper gastrointestinal tract by using colectomized rats.

The primary aim of this study was to characterize the carbohydrate that would be supplied to the colon for fermentation under physiological conditions. Colectomized rats were fed fiber-free diets or diets containing 5% (wt/wt) gum arabic. Four (fucose, galactose, glucosamine, and galactosamine) of 11 analyzed sugars accounted for 77% of the total sugar in ileal excreta from colectomized rats fed fiber-free diets. The three sugars in gum arabic, rhamnose, arabinose, and galactose, accounted for 84% of the total sugars in gum arabic ileal excreta. Comparisons of the sugar compositions of the ileal excreta, the water-soluble fractions of the excreta, and three gel filtration fractions of the water-soluble material with those of the water-soluble fraction of rat mucosa, the acetone-soluble fraction of pancreas, and pancreatin suggested that the major source of endogenous carbohydrate is mucin. Gum arabic increased the daily excretion of the four mucin-derived sugars (fucose, galactose, glucosamine, and galactosamine) by the colectomized rats from 473 mumol per day to 634 mumol per day. We conclude that mucin is the major endogenous carbohydrate excreted from the upper gut and that gum arabic increases the amount of this endogenous carbohydrate.     

Composition and antioxidant activity of the polysaccharides from cultivated Saussurea involucrata

Polysaccharides from cultivated Saussurea involucrata (CSIP) were purified, two major fractions (CSIP1-2 and CSIP2-3) were investigated for their molecular weights, monosaccharide compositions and in vitro antioxidant activities. The results suggested that the molecular weights of CSIP1-2 and CSIP2-3 were approximately 163.5 kDa and 88.6 kDa, respectively. CSIP1-2 was composed of glucose, galactose, xylose, rhamnose, arabinose and galacturonic acid with a molar ratio of 1.651:0.39:0.062:8.331:1.759:40.426. CSIP2-3 was composed of glucose, galactose, xylose, rhamnose, arabinose and galacturonic acid with a molar ratio of 0.762:0.657:0.112:5.587:0.318:44.655. Different scavenging activities on superoxide radical, DPPH radical and hydroxyl radical were observed in CSIP1-2 and CSIP2-3 at tested concentrations.     

Composition of ethanol-insoluble polysaccharides in water extracts of ripening tomatoes

The carbohydrate composition of the 80% ethanol-insoluble polysaccharides (EIP) from water extracts of ‘Rutgers,’ rin (ripening inhibitor) and nor (non-ripening) tomatoes has been determined. The amount of EIP extracted from ‘Rutgers’ fruit increased from 0.34 to 0.61 mg/g fr. wt during ripening little change occurred in rin or nor fruit. The carbohydrate composition (μg/g fr. wt) of EIP from mature green fruit was: galacturonic acid (48); rhamnose (3); arabinose (20); xylose (48); mannose (31); glucose (139); galactose (51). The most obvious changes that accompanied ripening were a 7.4-fold and 4-fold increase in galacturonic acid and rhamnose content, respectively. These changes were attenuated in the ripening mutants. EIP was fractionated into three major peaks by using DEAE-cellulose ion exchange chromatography. The first peak, which was not retained by the column, contained predominantly glucose and mannose, with lower amounts of galacturonic acid and galactose. The two retained peaks which eluted at 0.1 and 0.2 M sodium chloride contained primarily galacturonic acid, xylose, galactose and arabinose. The galacturonic acid content of these two fractions increased substantially during ripening, whereas the other components decreased. No changes were evident in the ripening mutants. No increase in water-soluble polysaccharides high in galactose content was observed during ripening.     

The effect of acarbose on the food intake, weight gain, and adiposity of LA/N-cp rats.

1. Groups of lean and obese LA/N-cp rats were administered the intestinal glucosidase inhibitor acarbose at 150 or 300 mg/kg diet from 7 until 17 weeks of age and the effects of the drug on food intake patterns and adiposity determined. 2. Dose related effects on body weights, adiposity and feed efficiency ratio were observed (control greater than 150 mg greater than 300 mg drug/kg diet) following treatment in both phenotypes, with the greatest differences observed in the obese phenotype. 3. Acarbose at both dosages was associated with phenotype-specific alterations in food intake amount and feeding pattern, resulting in an attenuation of age-associated increases in food intake. The feed efficiency ratio decreased in both phenotypes, and approached normally fed lean controls in obese rats administered the greater dosage. 4. These results indicate that patterns of food intake and weight gain differ markedly between lean and obese rats of this strain, and acarbose brings about a dose-related attenuation of developing food intake patterns in both phenotypes and which are associated with decreases in weight gain and adiposity. Thus, this drug may have therapeutic potential as an adjunct agent in the treatment of obesity and/or other disorders of carbohydrate intolerance.     

Metabolomic analysis of amino acid metabolism in colitic rats supplemented with lactosucrose

Intestinal inflammation causes metabolic disorders. The purpose of this study was to determine the effect of dietary supplementation with lactosucrose (LS) on the serum metabolome and intestinal luminal content of fatty acids in colitic rats. Colitis was induced in rats using trinitrobenzene sulfonic acid. Subsequently, rats received intragastric administration of either 250 mg LS/kg body weight or saline (the control group) every day for 5 weeks. Short-chain fatty acids in the intestinal lumen, blood profile, and metabolites in serum were measured, respectively, using gas chromatography, biochemistry analyzer, and nuclear magnetic resonance-based metabolomics combined with multivariate statistics. Metabolic effects of LS included: (1) decreases in concentrations of branched-chain amino acids (isoleucine and valine), alanine, citric acid, trimethylamine oxide and taurine, and the abundance of aspartate aminotransferase in serum; (2) increases in concentrations of glucose metabolites (including succinate) in serum; and (3) altered concentrations of butyrate in the cecal content and of butyrate and acetate in the colon content. The results indicate that LS supplementation to colitic rats affects whole-body metabolism of amino acids and release of aspartate aminotransferase and alkaline phosphatase from tissues into the blood circulation, and enhances the production of short-chain fatty acids in the intestinal lumen.     

Cholesterol metabolism in the genetically hypercholesterolemic rat (RICO). I. Measurement of turnover processes

The rates of mobile cholesterol turnover processes were measured by the isotopic equilibrium method in normocholesterolemic (SW) and hypercholesterolemic homozygote (RICO) rats fed a semi-synthetic base diet containing 0.05% cholesterol. When the absorption rate is similar in SW and RICO rats, the internal secretion rate is 60% higher in RICO (25.3 mg/day) than in SW (16.2 mg/day). This increase is compensated by an increase in fecal excretion (RICO: 5 mg/day; SW: 3.8 mg/day), urinary excretion (RICO: 1.7 mg/day; SW: 1.1 mg/day) and above all the transformation of cholesterol into bile acids (RICO: 24.2 mg/day; SW: 15.3 mg/day). The fact that 70 minutes after [14C]acetate administration, the only variations obtained in RICO compared to SW rats are a doubled sterol radioactivity in the small intestine and a tripled one in the liver suggests that the increase in internal secretion of the RICO rat has both an intestinal and hepatic origin. This cholesterogenic stimulation in RICO rats takes place in the jejunum as well as in the ileum and in the crypt cells as well as in the villosities. It is concomitant with a doubled cholesterolemia, a doubled intestinal, caecal and colon bile acid pool and a 20% increase in the enterocyte protein content.     

Characterization of an Acidic Polysaccharides from Carrot and Its Hepatoprotective Effect on Alcoholic Liver Injury in Mice

The characteristics of acidic polysaccharides extracted from Daucus carota L. var. sativa Hoffm were investigated and its hepatoprotective effects on alcoholic liver injury were determined in the mice model. A carrot polysaccharide (CPS-I: Carrot polysaccharide-I) with the molecular weight of 3.40×10⁴ kDa was isolated from Daucus carota L. and purified by diethylaminoethyl-52 and Sephadex G-150 column chromatography. The components were analyzed by HPLC, which revealed that CPS-I consisted of galacturonic acid, rhamnose, xylose, arabinose, fructose, and galactose at a relative ratio of 1 : 3.16 : 1.13 : 5.53 : 3.45 : 7.76. Structural characterization analysis suggested that CPS-I was mainly composed of →6)-β-D-Galp-(1→ and →5)-α-L-Araf-(1→. The hepatoprotective effect of CPS-I was evaluated by alcoholic liver injury mice model. The results showed that the administration of CPS-I (300 mg/kg/day) alleviated the alcoholic liver injury in mice by increasing the levels of ADH and ALDH and reducing oxidative stress. CPS-I ameliorated the pathological changes of liver characterized by lipid accumulation, and reduced the number of lipid droplets.     

Studies on plant gums. Isolation and characterisation of the major polysaccharide from Neem (Azadirachta indica) gum

Azadirachta indica (neem) exudate gum was treated with pronase for 48 h followed by chromatography on TEAE-cellulose and the major polysaccharide was isolated. The polysaccharide covalently associated with remnant protein, was homogeneous as indicated by rechromatography on TEAE-cellulose, paper electrophoresis, gel chromatography under dissociating conditions on Bio-Gel P-l00 and P-300. The monosaccharide units, galactose, arabinose, glucuronic acid, fucose and glucosamine were present in a molar ratio of 86 ∶ 70 ∶ 30 ∶ 10 ∶ 1. Thirteen amino acids constituted the protein portion. The linkage between the polysaccharide and the protein was a glucosaminyl asparginyl bond. Limited hydrolysis showed that fucose and arabinose were at the non-reducing ends of the polysaccharide and galactose and glucuronic acid were in the central core.     

Characterization of a biologically active arabinogalactan from the leaves of Plantago major L.

PMIa is a Type II arabinogalactan with anti-complementary activity isolated from the leaves of Plantago major L. It has a molecular weight of 77000–80000 Da and consists of arabinose (38%), galactose (49%), rhamnose (6%), galacturonic acid (7%) and 1.5% protein with hydroxyproline, alanine and serine as the main amino acids. Characterization of PMIa by methylation and GC-MS, methanolysis and GC, Smith degradation, weak acid hydrolysis, ¹³C-NMR, ¹H-NMR, two-dimensional heteronuclear NMR and DEPT show that it consists of 1,3-linked galactan chains with 1,6-linked galactan side chains attached to position 6. The side chains are further branched in position 3 with 1,3-linked galactose residues which have 1,6-linked galactose attached to position 6; these 1,3- and 1,6-linked galactose chains altogether probably form a network. Terminal and 1,5-linked arabinose in furanose form are attached to the galactan mainly through position 3 of the 1,6-linked galactose side chains.