Extraction optimization, structure features, and bioactivities of two polysaccharides from Corydalis decumbens.

Two polysaccharides (CPS1 and CPW2) from Corydalis decumbens were obtained to develop insights into natural medical resources. Optimal extraction conditions of total sugars were researched using the method of response surface methodology, polysaccharides were purified using a combination of ethanol precipitation and anion-exchange chromatography, and structure features were analyzed by scanning electron microscopy, transmission electron microscopy, and Congo-red assay. The bioactivities were estimated in terms of antioxidant and anti-inflammatory effects. Total sugars were extracted with an experimental yield of 32.74% under optimum conditions. CPS1 and CPW2 were purified with yields of 12.01% and 8.23%, respectively. CPS1 was a unique polysaccharide with a molecular weight (Mw) of 360 kDa and consisted of glucose, galactose, mannose, and arabinose in a ratio of 4.9:2.0:1:1.9, and CPW2 was composed of glucose with the Mw of 550 kDa. CPS1 possessed a four-helix conformation, and CPW2 was identified as a linear molecule without branched and entangled chains. The mRNA expressions of TNF-α (71.80%), IL-1ß (56.55%), IL-6 (43.98%), and COX-2 (91.88%) in LPS-stimulated RAW 264.7 cells were significantly inhibited by 75 µg/mL CPS1 (P < 0.0001), while CPW2 showed lower inhibitory effects than CPS1. Compared with CPW2, CPS1 showed stronger scavenging abilities for hydroxyl (EC50 = 520.46 µg/mL), ABTS (EC50 = 533.99 µg/mL), and superoxide (EC50 = 1512.06 µg/mL) radicals. CPS1 with four-helix conformation exhibited more outstanding bioactivities than CPW2 without entangled chains.

A polysaccharide from Umbilicaria yunnana: Structural characterization and anti-inflammation effects.

A polysaccharide JUYP was isolated and purified from Umbilicaria yunnana. The detailed structure of JUYP was studied using gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), methylation-GC-MS, nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM). A homogeneous polysaccharide JUYP was obtained with the yield of 21.2% and average molecular weight (Mw) of 577 kDa. Monosaccharide composition analysis indicated that JUYP was composed of glucose, galactose and mannose with a molar ratio of 2.3:1:0.7. Structural analyses demonstrated that the dominate components in JUYP were 6-ß-D-Glcp, and other sugar residues included 2,4-ß-D-Manp and T-ß-D-Galf. TEM images further revealed JUYP was a linear branched molecule with entangled chains. Based on the anti-inflammatory assays, 1 µg/mL of JUYP exhibited good inhibitory effects on TNF-α, IL-6, IL-1ß and COX-2 mRNA expressions in LPS-stimulated RAW 264.7 cells, while the inhibitory effects (87.8% for mRNA, 55.89% for protein) of JUYP on IL-1ß expressions were more significant than that of dexamethasone (DXMS, 61.6% for mRNA, 35.15% for protein) (p<0.01).

Structural characterization of a novel polysaccharide from Sargassum thunbergii and its antioxidant and anti-inflammation effects.

A novel polysaccharide STSP-I was isolated and purified from Sargassum thunbergii. Its structure and bioactivity were studied using gas chromatography (GC), fourier transform infrared spectroscopy (FTIR), periodate oxidation-smith degradation, partial acid hydrolysis, methylation-GC-MS, nuclear magnetic resonance (NMR), transmission electron microscopy (TEM), radicals scavenging assays and anti-inflammatory assays. STSP-I was consisted of fucose and galactose with a molar ratio of 1.2:1, and its mass was 373 kDa. The main structural components of STSP-I were →4)-α-D-Galp-(1→ and →3)-ß-L-Fucp-(1→, STSP-I was a non-branched polysaccharide, and TEM further revealed the existence of entangled chains and linear forms. Compared with Vitamin C (Vc), STSP-I showed a higher scavenging effect of superoxide radical (EC50 = 0.22 mg/mL) and an equivalent scavenging effect of hydroxyl radical (EC50 = 0.88 mg/mL). STSP-I also exhibited good inhibitory effects of TNF-α, IL-6 and COX-2 mRNA expressions in LPS-stimulated RAW 264.7 mouse macrophage cells, and the inhibitory effects were more than 91% at the concentrations of 75 and 150 µg/ml. The results indicate that the polysaccharide STSP-I from S. thunbergii with the linear structure may serve as potential antioxidant and anti-inflammatory agents.

Structure of an entangled heteropolysaccharide from Pholidota chinensis Lindl and its antioxidant and anti-cancer properties.

A major polysaccharide PCP-I was isolated and purified from Pholidota chinensis Lindl. The physicochemical and structural properties of PCP-I were studied using high-performance size-exclusion chromatography (HPSEC), gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), periodate oxidation-smith degradation, methylation-GC-MS analysis, nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) analysis. PCP-I was homogeneous with molecular weight (Mw) of 249kDa and composed of xylose and fucose at a molar ratio of 2.45:1. The repeating structural units of PCP-I were →3)-α-D-Xylp-(1→ and →4)-α-L-Fucp-(1→, the terminal fractions were T-D-GalAp, and TEM further revealed that PCP-I was the entangled microstructure which was composed of four non-branched single chains. Compared with Vitamin C (Vc) and 5 fluorine urine (5-Fu), PCP-I showed scavenging effects of superoxide (EC50=1.09mg/mL) and hydroxyl (EC50=0.11mg/mL) radicals equivalent to Vc, and PCP-I (IC50=69.54µg/mL) also exhibited good anti-proliferation capability for human colon cancer cell line caco-2.

Quantitative Structure Activity Relationship Models for the Antioxidant Activity of Polysaccharides.

In this study, quantitative structure activity relationship (QSAR) models for the antioxidant activity of polysaccharides were developed with 50% effective concentration (EC50) as the dependent variable. To establish optimum QSAR models, multiple linear regressions (MLR), support vector machines (SVM) and artificial neural networks (ANN) were used, and 11 molecular descriptors were selected. The optimum QSAR model for predicting EC50 of DPPH-scavenging activity consisted of four major descriptors. MLR model gave EC50 = 0.033Ara-0.041GalA-0.03GlcA-0.025PC+0.484, and MLR fitted the training set with R = 0.807. ANN model gave the improvement of training set (R = 0.96, RMSE = 0.018) and test set (R = 0.933, RMSE = 0.055) which indicated that it was more accurately than SVM and MLR models for predicting the DPPH-scavenging activity of polysaccharides. 67 compounds were used for predicting EC50 of the hydroxyl radicals scavenging activity of polysaccharides. MLR model gave EC50 = 0.12PC+0.083Fuc+0.013Rha-0.02UA+0.372. A comparison of results from models indicated that ANN model (R = 0.944, RMSE = 0.119) was also the best one for predicting the hydroxyl radicals scavenging activity of polysaccharides. MLR and ANN models showed that Ara and GalA appeared critical in determining EC50 of DPPH-scavenging activity, and Fuc, Rha, uronic acid and protein content had a great effect on the hydroxyl radicals scavenging activity of polysaccharides. The antioxidant activity of polysaccharide usually was high in MW range of 4000-100000, and the antioxidant activity could be affected simultaneously by other polysaccharide properties, such as uronic acid and Ara.

Structure elucidation of a non-branched and entangled heteropolysaccharide from Tremella sanguinea Peng and its antioxidant activity.

A crude polysaccharide was extracted from the edible fungi Tremella sanguinea Peng, and a polysaccharide TSP-II (31.56%) was separated and purified from the crude polysaccharide. TSP-II was a homogeneous polysaccharide by the high-performance size-exclusion chromatography (HPSEC), had a molecular weight of 356kD and consisted mainly of mannose, xylose, galactose and glucose at a molar ratio 5.9:2.4:1:1.1. The structural assignment of TSP-II was carried out using fourier transform infrared spectroscopy (FTIR) analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance (NMR) studies, and the repeating unit of TSP-II was thus determined. The result indicated that →3)-α-d-Manp-(1→, →2)-α-d-Xylp-(1→, →6)-α-d-Glcp-(1→ and →3)-α-d-Galp-(1→ formed the major components of the main-chain structure, and TSP-II was a non-branched polysaccharide. Transmission electron microscopy (TEM) analysis revealed a primary non-branched and entangled state in its microstructure. TSP-II had higher scavenging activities on hydroxyl radical (EC50=0.088mg/ml) and superoxide radical (EC50=0.127mg/ml) than Vitamin C (Vc).

Structure elucidation of a major fucopyranose-rich heteropolysaccharide (STP-II) from Sargassum thunbergii.

A crude polysaccharide was extracted from the edible algae S. thunbergii. DEAE-Sepharose CL-6B column chromatography was used to separate and purify a major polysaccharide STP-II (63.75%) from the crude polysaccharide. STP-II was found to be a homogeneous polysaccharide with a single peak by high-performance size-exclusion chromatography with a Sugar KS-804 column, have a molecular weight of 550 kD, and consist mainly of fucose, xylose, galactose, glucose and glucuronic acid. The structural assignment of STP-II was carried out using Fourier transform infrared spectroscopy analysis, periodate oxidation-smith degradation, partial hydrolysis with acid, methylation analysis and nuclear magnetic resonance studies, and the repeating unit of STP-II was thus determined. The result indicated that (1→3)-linked-fucose, (1→3)-linked-xylose and (1→3)-linked-galactose formed the major components of the main-chain structure, and the branch ratios were 17.5%. The branching and terminal residues were (1→2)-linked-glucuronic acid, (1→4)-linked-glucose, (1→)-linked-xylose and (1→)-linked-4-O-acetyl-glucose, respectively.

Extraction Optimization, Characterization and Bioactivities of a Major Polysaccharide from Sargassum thunbergii.

Sargassum thunbergii is a kind of natural edible algae. STP (S. thunbergii polysaccharides) was considered as the main bioactive compounds in S. thunbergii. To obtain the optimal processing conditions for maximum total sugar yield, single factor investigation and response surface methodology (RSM) were employed. The optimal processing conditions were as follows: liquid to solid ratio 120 mL/g, extraction time 210 min, extraction temperature 97°C. The experimental yield 7.53% under optimized conditions was closely agreed with the predicted yield 7.85% of the model. The major polysaccharide fraction from S. thunbergii (named STP-II) was purified by DEAE-Sepharose CL-6B column chromatography. High-performance size-exclusion chromatography (HPSEC), gas chromatography (GC) and high-performance liquid chromatography (HPLC) were used to identify its characterizations, and in vitro antioxidant assays and cytotoxicity assays were used to research its bioactivities. The purified fraction STP-II (63.75%) was a single peak in HPSEC with Sugar KS-804 column, had a molecular weight of 550KD, and comprised mainly of fucose, xylose, galactose, glucose and glucuronic acid. STP-II had higher scavenging activities on hydroxyl radical (76.72% at 0.7 mg/mL) and superoxide radical (95.17% at 2 mg/mL) than Vitamin C (Vc). STP-II also exhibited the capability of anti-proliferation in Caco-2 cells. STP-II possessed good antioxidant and inhibitory activity against human colon cancer Caco-2 cells in vitro and could be explored as novel natural functional food.

Structural investigation of a polysaccharide (DMB) purified from Dioscorea nipponica Makino.

A water-soluble polysaccharide was isolated from the aqueous extract of Dioscored nipponica Makino. Compositional analysis, IR analysis, methylation analysis, and NMR studies ((1)H, (13)C, (1)H(1)H COSY, HSQC, and HMBC) revealed the presence of the following repeating unit in the polysaccharide:

Optimization of total polysaccharide extraction from Dioscorea nipponica Makino using response surface methodology and uniform design.

On the base of single factor investigation, effects of extraction temperature, extraction time and ratio of water to material as well as their interactions on the yield of total polysaccharide from Dioscorea nipponica Makino were studied by uniform design and response surface methodology, respectively. The optimal process conditions were obtained by response surface methodology as follows: ratio of liquid to solid 33:1, extracting duration 134 min, and extracting temperature 95 °C, under optimized conditions, and the experimental yield 3.82% agreed closely with the predicted yield 3.9%. The tri-dimensional response surfaces were plotted by design-expert, and it was indicated that both extraction temperature and extraction time had interaction effects on the response value and there were no interaction effects of extraction time and liquid:solid ratio. Therefore, the application of response surface methodology in the extraction of total polysaccharide from D. nipponica Makino is more significant than uniform design.

[The Elp4 subunit of human Elongator complex partially complements the growth defects of yeast ELP4 deletion strain].

In this study, we performed in vivo experiments to determine the function of human Elongator subunit Elp4 by using a yeast complementary system. Our results indicated that though human ELP4 was not able to complement the growth defects of the ELP4 deletion mutant strain to high concentration salt, it partially reduced the sensitivity of mutant strain to caffeine, high temperature and 6-AU. Gene expression analysis indicated that human ELP4 partially resumed the slow activation of the PHO5 gene caused by the deletion of yELP4 under the low phosphate concentration. Meanwhile, under the condition of heat shock treatment, hELP4 increased the expression level of SSA3 gene. All these data demonstrated that human ELP4 can partially complement the growth defects and restore the slow activation of certain genes of the yELP4 deletion strain. These results indicate that human Elp4 subunit has similar functions to that of the yeast.