polygalacturonic-acid and 1-1-diphenyl-2-picrylhydrazyl

To investigate the composition and structural characteristics of cell wall polysaccharides, three pectic fractions and two hemicellulose fractions, namely water-soluble pectin (WSP), chelator-soluble pectin (CSP), sodium carbonate-soluble pectin (NSP), 1 mol/L KOH soluble hemicellulose (KSH-1) and 4 mol/L KOH soluble hemicellulose (KSH-2), were isolated from Chinese quince fruits. The five fractions exhibited structural and compositional variation. The results showed NSP was the predominant cell wall polysaccharide fraction in the fruit. All pectic fractions had a low degree of esterification (31.7-42.4%). WSP fraction had the highest thermal stability among the five fractions. The polysaccharide chain lengths ranged from 19.4 nm to 121.4 nm. CSP had the highest molecular weight, giving it also the highest solution viscosity. NMR spectra revealed that NSP was composed of RG-I and galacturonic acid main chains, KSH-1 was composed of 1,4-β-D-Xylp backbone attached to 1,5-α-L-Araf units. Among the five fractions, CSP has the highest DPPH radical scavenging activity while KSH-1 has the highest reducing power. This study can contribute to the applications of Chinese quince fruit polysaccharides in food and pharmaceutical industries.

Topics: Antioxidants; Biphenyl Compounds; Cell Wall; Free Radicals; Fruit; Hexuronic Acids; Hot Temperature; Microscopy, Atomic Force; Molecular Weight; Pectins; Picrates; Polysaccharides; Powders; Rheology; Rosaceae; Shear Strength; Spectroscopy, Fourier Transform Infrared; Stress, Mechanical; Viscosity

The microwave-assisted extraction of pectin from sweet lemon peel (SLP) was optimized using Box-Behnken design. The highest pectin yield (25.31%) was observed under optimal condition (microwave power of 700 W, irradiation time of 3 min and pH of 1.5). The physicochemical, structural and some bioactivity of the SLP pectin isolated at optimum condition was evaluated. The SLP pectin was rich in galacturonic acid and galactose (87.2 mol%), high in molecular weight (615.836 kDa) and low in degree of esterification (1.2-35.1%). Furthermore, the SLP pectin was composed of 55.7% linear region (homogalacturonan) and 42.2% hairy region (rhamnogalacturonan-I). Also, the FT-IR and H-NMR results confirm the major presence of low methylated galacturonic acid rich structure in the isolated samples. In addition, SLP pectin showed good emulsifying and antioxidant properties. A pseudoplastic flow behavior was observed for SLP pectin solution at higher concentrations (1% w/v <). These results represent an inexpensive source for pectin extraction with high pectin yield and good properties.

Topics: Antioxidants; Biphenyl Compounds; Citrus; Emulsions; Esterification; Fruit; Galactans; Galactose; Hexuronic Acids; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Microwaves; Molecular Weight; Pectins; Picrates; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction

Pinto bean pod polysaccharide (PBPP) was successfully extracted with yield of 38.5g/100g and the PBPP gave total carbohydrate and uronic acid contents of 286.2mg maltose equivalent/g and 374.3mgGal/g, respectively. The Mw of PBPP was 270.6kDa with intrinsic viscosity of 0.262dm(3)/g, which composed of mannose (2.5%), galacturonic acid (15.0%), rhamnose (4.0%), glucose (9.0%), galactose (62.2%), xylose (2.9%) and arabinose (4.3%) with trace amount of ribose and fucose. The result suggested that PBPP has a spherical conformation with a highly branched structure. Fourier Transform Infrared analysis showed that PBPP has a similar structure as commercial pectin with an esterification degree of 59.9%, whereas scanning electron microscopy study showed that the crude polysaccharide formed a thin layer of film that was made of multiple micro strands of fibre. PBPP exhibited substantial free radical scavenging activity (7.7%), metal reducing capability (2.04mmol/dm(3)) and α-amylase inhibitory activity (97.6%) at a total amount of 1mg. PBPP also exhibited high water- and oil-holding capacities (3.6g/g and 2.8g/g, respectively). At a low concentration, PBPP exhibited emulsifying activity of 39.6% with stability of 38.6%. Apart from that, PBPP was able to show thickening capability at low concentration (0.005kg/dm(3)).

Topics: alpha-Amylases; Biphenyl Compounds; Enzyme Inhibitors; Fabaceae; Free Radical Scavengers; Hexoses; Hexuronic Acids; Hydrolysis; Maltose; Molecular Structure; Picrates; Polysaccharides

In this report, a water-soluble polysaccharide was obtained from the dried stems of Dendrobium officinale Kimura et Migo by hot-water (70-75°C) extraction and 85% ethanol precipitation, and successively purification by DEAE-cellulose anion-exchange chromatography and gel-permeation chromatography. The D. officinale polysaccharide (DOP) has a molecular weight of 8500Da. Monosaccharide composition analysis reveals that DOP is composed of mannose, glucose, and arabinose with a trace of galacturonic acid in a molar ratio of 6.2:2.3:2.1:0.1. Periodate oxidation-smith degradation and 1D and 2D NMR spectroscopy analysis suggest the predominance of mannose and glucose, and it contains a 2-O-acetylglucomannan and (1→4)-linked-β-d-mannopyranosyl and (1→4)-linked-β-d-glucopyranosyl residues. Atomic force microscope shows that DOP mainly exists as rod-shaped chains, supporting high degrees of polymerization. The antioxidant activities of the polysaccharide in vitro assay indicate that DOP has good scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, higher scavenging activity of hydroxyl radical, and metal chelating activities.

Topics: Antioxidants; Arabinose; Biphenyl Compounds; Carbohydrate Conformation; Chromatography, Gel; Chromatography, Ion Exchange; Dendrobium; Glucose; Glycosides; Hexuronic Acids; Mannose; Molecular Weight; Picrates; Plant Extracts; Plant Stems; Polysaccharides; Solid Phase Extraction

An acidic polysaccharide APMO was isolated from Morinda officinalis by alkaline solvent extraction followed by fractionation treatments. Its antioxidant activities were evaluated by various methods in vitro, APMO presented excellent capability in scavenging DPPH radicals, chelating ferrous ions and inhibiting hemolysis of rats erythrocyte induced by H2O2, which was stronger than those of Vc at high concentration. Moreover, APMO displayed moderate reducing power. Physicochemical characteristics of APMO were observed by a combination of chemical and instrumental analysis. APMO predominantly consisted of galacturonic acid, arabinose and galactose. Galacturonic acid was assigned to be 1→4 glycosyl linkage in the skeleton of APMO.

Topics: Animals; Arabinose; Biphenyl Compounds; Erythrocytes; Free Radical Scavengers; Free Radicals; Galactose; Hemolysis; Hexuronic Acids; Hydrogen Peroxide; Male; Morinda; Oxidation-Reduction; Picrates; Plant Extracts; Polysaccharides; Rats; Rats, Sprague-Dawley; Reducing Agents

The chemical compositions and bioactivities of crude tea polysaccharides (TPS) from the out-of-date tea leaves (beyond their useful date), namely Xihu Longjing (XTPS), Anxi Tieguanyin (TTPS), Chawentianxia (CTPS) and Huizhoulvcha (HTPS), in market were investigated. These TPS showed similar neutral sugar content and different distribution of molecular weight (1-800 kD). These crude TPS were mainly composed of rhamnose, arabinose, galactose, glucose, xylose, mannose, and galacturonic acid. IR spectra confirmed that these crude TPS were composed of polysaccharide, protein and uronic acids. These TPS showed similar DPPH scavenging activity and exhibited lower DPPH scavenging activities than Vc within 25-200 μg/mL. However, these TPS with higher concentrations (200-400 μg/mL) showed similar DPPH scavenging activity with Vc. HTPS exhibited significant higher superoxide anion scavenging activity than others TPS and gallic acid. XTPS showed significant higher inhibitory effects on α-glucosidase and α-amylase with inhibitory percentages of 64.35% and 82.24% than others TPS. TTPS, XTPS, and HTPS exhibited similar inhibition ability on α-d-glucosidase and α-amylase. The overdue tea leaves can be a resource of tea polysaccharides as function food.

Topics: alpha-Amylases; alpha-Glucosidases; Animals; Antioxidants; Biphenyl Compounds; Camellia sinensis; China; Food Analysis; Food Preservation; Glycoside Hydrolase Inhibitors; Hexuronic Acids; Lipid Peroxidation; Liver; Male; Monosaccharides; Picrates; Plant Extracts; Plant Leaves; Polysaccharides; Rats; Tea; Tissue Extracts; Uronic Acids