Physicochemical, rheological, antioxidant and immunological properties of four novel non-inulin (poly)saccharides from Asparagus cochinchinensis.

The impacts of four extraction techniques, including hot water, ultrasonic-assisted, complex enzyme-assisted and acid-assisted methods, on the morphological, physicochemical properties and bioactivities of Asparagus cochinchinensis (poly)saccharides (EACP, WACP, UACP, and AACP) were investigated and compared. The four samples were mainly composed of glucose, fructose, and galactose with molar ratios of 50.8:22.7:4.4 for WACP, 53.9:26.0:5.3 for UACP, 35.6:14.1:21.4 for AACP and 45.0:15.6:9.0 for EACP, respectively. The rheological result showed that ACPs were non-Newtonian fluids. EACP with high purity (97.65 %) had good DPPH, O2- and ABTS+ radical scavenging activities, and significantly promoted the proliferation of the RAW264.7 cells at low concentration. UACP had good Fe2+ chelating ability, radical (DPPH, O2- and OH) scavenging activities, which might be attributed to the existence of triple-helix structure. AACP had high yield, molecular weight (17,477.2 Da), high crystallinity (23.33 %), and good radical (OH and ABTS+) scavenging activities. All four significantly stimulated the transcript expression levels of TNF-α, IL-1ß and IL-6, as determined by RT-PCR. These results suggest that the exploitation and utilization of non-inulin (poly)saccharides extracted by ultrasonic-assisted, complex enzyme-assisted and acid-assisted extraction methods are potentially valuable as effective and natural immune adjuvants and antioxidants.

Preparation, structural characteristics and antioxidant activity of polysaccharide and its metal chelates from the peel of Dioscorea oppositifolia L.

Two metal chelates of Dioscorea oppositifolia L. peel polysaccharides (DTP) were prepared: iron chelate (DTP-Fe) and zinc chelate (DTP-Zn). The physicochemical properties of the polysaccharide and its metal chelates were assessed by UV-Vis absorption spectroscopy, Fourier-transform infra-red spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Antioxidant activities were evaluated by DPPH, ABTS + and hydroxyl radical scavenging assays. According to ICP-MS, the iron content of DTP-Fe was 9.47%, while the zinc content of DTP-Zn was 4.02%. The antioxidant capacity of DTP-Fe increased with the increase of concentration, and its overall activity was higher than that of DTP and DTP-Zn. This polysaccharide-iron chelate can be developed and utilised as an antioxidant and multifunctional iron supplement. DTP-Zn showed the potential to be a natural antioxidant and zinc supplement food.

Structure and Bioactivities of a Novel Polysaccharide Extracted From Dendrobium huoshanense by Subcritical Water.

In this study, the polysaccharide was extracted by subcritical water from Dendrobium huoshanense. A novel polysaccharide (DHPs-1) was obtained through several purification steps and its structure and bioactivity were investigated. Structural analysis indicated that the weight-average molecular weight of DHPs-1 was 5.0 × 104 Da and it was mainly composed of glucose (65.04%), mannose (14.23%), galactose (8.17%), galacturonic acid (6.41%), rhamnose (2.34%), and xylose (1.25%). 1,4-Glcp, and 1,4,6-Galp were existed in the backbone of DHPs-1. The residues of 1,3,4-Galp, 1,4-Manp, 1,4-Galp, and 1,3,4,6-Galp could be in the backbone or the side chains with the non-reducing terminal of α-Manp. Bioactivity tests indicated that DHPs-1 had immunomodulatory activity in that it significantly enhanced transcript levels of cytokines [Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6), Interleukin-1ß (IL-1ß), and Interleukin-10 (IL-10)]. DPPH and hydroxyl radical scavenging tests showed that it had good antioxidant activity. These results reveal that DHPs-1 could be developed as a safe immunomodulatory agent and antioxidant for pharmacological or functional food applications.

Three-phase extraction of polysaccharide from Stropharia rugosoannulata: Process optimization, structural characterization and bioactivities.

The isolation of Stropharia rugosoannulata polysaccharide (SRP) by three-phase extraction was optimized, and its structure and biological activities were identified. The optimal extraction conditions were: mass fraction of ammonium sulfate, 20%; volume ratio of sample solution to t-butanol, 1:1.5; extraction temperature, 35°C. Under these conditions, the yield of SRP was 6.85% ± 0.13%. SRP was found to be composed of glucose (35.79%), galactose (26.80%), glucuronic acid (9.92%), fructose (8.65%), xylose (7.92%), fucose (4.19%), arabinose (3.46%) and rhamnose (3.26%), with the molecular weight of 27.52 kDa. The results of DPPH, hydroxyl, ABTS+ radical scavenging and reducing power tests showed that SRP had good antioxidant capacities. SRP had no cytotoxic effect on RAW264.7 macrophages at the concentrations of 25-200 µg/mL, and could significantly promote phagocytosis activity and cell migration according to CCK-8 assay, phagocytosis assay and cell scratch experiment. SRP can significantly stimulate the transcript expression levels of TNF-α, IL-1ß and IL-6, as determined by RT-PCR and Western blot assays. SRP activated the TLR4/NF-κB signaling pathway, and autophagy also occurred. These results suggest that SRP is a safe antioxidant and immunomodulator, and that it can be used in the development of functional foods and/or pharmaceuticals.

A study on the short-term effect of particulate matter pollution on hospital visits for asthma in children in Shanghai, China.

Recently, particulate matter pollution has been worsening, which has been affecting the asthma visits in children. In this study, we assessed the short-term effects of PM10 and PM2.5 on asthma visits in children in Shanghai, China from January 1, 2009 and December 31, 2010, using a generalized additive model. We controlled the confounding factors, such as long-term trends, week day effect, and weather elements. The lag effects of different age subgroups (≤ 2 yr, 3-5 yr, and 6-18 yr subgroups) were performed. The results showed significant effects of PM10 and PM2.5 on asthma visits in children, though the seasonal lags varied for the three age subgroups. In general, the effect of PM2.5 on asthma visits in children was stronger and more acute than that of PM10. PM2.5 showed the highest relative risk of 1.192 at lag 0 day in summer; and PM10 showed the highest relative risk of 1.073 at lag 3 day in autumn. Overall, particulate matter pollution showed a greater effect on relatively younger children. In particular, the ≤ 2 yr subgroup showed the highest seasonal relative risk of PM10. Especially, seasonal relative risk of PM10 in autumn for the ≤ 2 yr subgroup was much higher than that for the other two subgroups. The 3-5 yr and 6-18 yr subgroups showed the highest seasonal relative risk of PM2.5 in summer and winter, respectively. But the pediatric visits data we obtained cannot reflect the true prevalence of asthma and multiple visits. Thus, selection bias may exist in our analysis.

Acid-Catalyzed Water Extraction of Two Polysaccharides from Artemisia argyi and Their Physicochemical Properties and Antioxidant Activities.

In this study, two purified polysaccharide fractions, Artp1 and Artp2, were obtained using acid-catalyzed water extraction, and then purified by DEAE-52 cellulose and Sephadex G-200 column chromatography from the crude polysaccharides of Artemisia argyi. Their physicochemical properties were investigated by gel permeation chromatography (GPC), high-performance anion exchange chromatography (HPAEC), Fourier transform infrared (FT-IR), scanning electron microscope (SEM), thermal analysis, and methylation analysis. The average molecular weight (Mw) of Artp1 and Artp2 were estimated to be 42.17 kDa and 175.22 kDa, respectively. Monosaccharide composition analysis revealed that the Rha, Gal, and GalA occupied main proportion in Artp1 with the molar ratio of 25.1:24.7:40.4, while the Rha, Gal, Xly, and GalA occupied the main proportion in Artp2 with the molar ratio of 16.7:13.5:12.8:38.7. Due to the high yield and the relatively high carbohydrate content, the Artp1 was determined by the methylation analysis and NMR. The results of Artp1 indicated that 1,4-GalpA and 1,2,4-Rhap formed the backbone with some 1,2-Rhap, 1,3-Galp, and 1,6-Galp in the backbone or the side chains. Artp1 and Artp2 exhibited effective antioxidant activities by DPPH radical scavenging assay and hydroxyl radical scavenging assay in a dose-dependent manner. These investigations of the polysaccharides from A. argyi. provide a scientific basis for the uses of Artp1 and Artp2 as ingredients in functional foods and medicines.

A review of the impact of outdoor and indoor environmental factors on human health in China.

The Intergovernmental Panel on Climate Change (IPCC) reported that global climate change has led to the increased occurrence of extreme weather events. In the context of global climate change, more evidence indicates that abnormal meteorological conditions could increase the risk of epidemiological mortality and morbidity. In this study, using a systematic review, we evaluated a total of 175 studies (including 158 studies on outdoor environment and 17 studies on indoor environment) to summarize the impact of outdoor and indoor environment on human health in China using the database of PubMed, Web of Science, the Cochrane Library, and Embase. In particular, we focused on studies about cardiovascular and respiratory mortality and morbidity, the prevalence of digestive system diseases, infectious diseases, and preterm birth. Most of the studies we reviewed were conducted in three of the metropolises of China, including Beijing, Guangzhou, and Shanghai. For the outdoor environment, we summarized the effects of climate change-related phenomena on health, including ambient air temperature, diurnal temperature range (DTR), temperature extremes, and so on. Studies on the associations between temperature and human health accounted for 79.7% of the total studies reviewed. We also screened out 19 articles to explore the effect of air temperature on cardiovascular diseases in different cities in the final meta-analysis. Besides, modern lifestyle involves a large amount of time spent indoors; therefore, indoor environment also plays an important role in human health. Nevertheless, studies on the impact of indoor environment on human health are rarely reported in China. According to the limited reports, adverse indoor environment could impose a high health risk on children.

Short-term effect of extreme air temperature on hospital emergency room visits for cardiovascular diseases from 2009 to 2012 in Beijing, China.

Extreme air temperature directly affected human health. However, the short-term effect of extreme air temperature on the incidence of cardiovascular diseases has rarely been reported in China. In this study, we focused on Beijing, China, and assessed the effects of cold/warm days and nights on the number of hospital emergency room (ER) visits for cardiovascular diseases from 2009 to 2012. We used a generalized additive model (GAM) to estimate the association between extreme air temperature and the number of hospital ER visits for cardiovascular diseases. We divided the entire study group into two gender subgroups and three age subgroups. The results showed that the short-term effect of extreme air temperature on hospital ER visits for cardiovascular diseases was more profound in females and the elderly (aged ≥ 75 years). Among all the study subgroups, the highest relative risk (RR) of cardiovascular diseases associated with extremely cold days, warm days, cold nights, and warm nights was 3.0% (95% CI, 1.6%-4.4%), 0.8% (95% CI, - 0.9%-2.6%), 2.8% (95% CI, 1.6%-4.2%), and 1.8% (95% CI, 0.6%-4.3%), respectively. Overall, the effect of extremely low air temperature (during both days and nights) on the incidence of cardiovascular diseases was stronger and more acute than that of extremely high air temperature.

Impact of temperature changes between neighboring days on COPD in a city in Northeast China.

Sudden temperature changes between neighboring days (T24h) have adverse effects on human health. In this study, we used a time series analysis to evaluate the impact of T24h on the number of hospital admissions for chronic obstructive pulmonary disease (COPD) from 2009 to 2012 in Changchun (the capital of Northeast China's Jilin province). We performed the analysis in a generalized additive model (GAM), and the controlling factors included long-term trends, day of the week effect, and the selected weather elements. We divided the entire study group into two gender subgroups (males and females) and two age subgroups (aged < 65 years and aged ≥ 65 years). T24h showed the greatest effect on the entire study group at lag 3 days. In particular, the greatest effect of T24h on females (males) occurred at lag 1 day (lag 3 days); the greatest effect of T24h on the aged ≥ 65 years (aged < 65 years) occurred at lag 1 day (lag 6 days). This indicates that temperature changes between neighboring days have a relatively more acute effect on the elderly and the females than on the younger people and the males. When T24h is less than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 4 days during the warm season (1.025, 95% CI: 0.981, 1.069) and lag 3 days during the cold season (1.019, 95% CI: 0.988, 1.051). When T24h is greater than zero, the highest RR of the number of hospital admissions for COPD occurred at lag 6 days during the warm season (1.026, 95% CI: 0.977, 1.077) and lag 5 days during the cold season (1.021, 95% CI: 0.986, 1.057). The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing COPD in Changchun, China.

Effect of diurnal temperature range on outpatient visits for common cold in Shanghai, China.

To evaluate the correlations between diurnal temperature range (DTR) and the number of outpatient visits for common cold from Jan. 1, 2008, to Dec. 31, 2010, in the Shanghai metro area; we used a distributed lag non-linear model together with a Poisson regression model. The controlling factors included long-term trends and day of the week in outpatient visits for common cold and the selected weather elements. The entire study group was divided into three different age subgroups, including ≤ 15, 15-65, and ≥ 65 years old. We found some non-linear J-patterns between DTR and daily outpatient visits for common cold. At lag 0 day, the number of outpatient visits for common cold would increase by 11.1% per 1 °C increase in DTR. The greater the DTR, the more it affects outpatient visits for common cold, especially for the ≥ 65 years age group. In addition, DTR plays a more important role in outpatient visits for common cold in spring and winter compared with other seasons of the year. Our study showed that DTR is a risk factor that contributes to common cold. Results in this study can provide scientific evidence for the local authorities in improving preventive measures of the healthcare system.

Physicochemical properties and bioactivities of original and Se-enriched polysaccharides with different molecular weights extracted from Pleurotus ostreatus.

Three polysaccharides (WZP1, WZP2, WZP3) and their Se-enriched products (SeWZP1, SeWZP2 and SeWZP3) were obtained from Pleurotus ostreatus using a simple, rapid method and HNO3-Na2SeO3 method, respectively. The molecular weight distribution profiles of all samples except SeWZP2 showed double peaks. The average molecular weights (Mw) of WZP1-3 were 48.6 kDa, 20.2 kDa and 11.8 kDa, respectively, and of SeWZP1-3 were 19.6 kDa, 37.7 kDa, 14.5 kDa, respectively. The complexity of monosaccharide composition of WZP1-3 was inversely proportional to the ethanol concentration used in the ethanol precipitation process. Additionally, the results of biological activity tests indicated that α-glucosidase inhibitory activity of WZP1-3 was related to the molecular weight and the monosaccharide composition complexity. The selenized modification can improve the α-glucosidase-inhibiting, hydroxyl radical-scavenging activity of P. ostreatus polysaccharides. Therefore, by improving their bioactivities by selenization, the polysaccharides of P. ostreatus could be utilized as a natural health food supplement.

Short-term effect of PM2.5 on pediatric asthma incidence in Shanghai, China.

Recent epidemiological studies pointed out that air pollution has a significant impact on pediatric asthma. Shanghai is one of the biggest cities in China, and the short-term effect of atmospheric particulate matter on the incidence of pediatric asthma has become a hot topic. From January 1, 2009, to December 31, 2010, we used daily measurements of pollutant concentrations, daily weather data, and daily records of pediatric asthma hospital visits from local authorities to evaluate the short-term effect of air pollution on pediatric asthma incidence in Shanghai, China. We used a generalized additive model (GAM) in the analysis, and the controlled confounding factors include long-term trends, day-of-the-week effects, and weather elements. We divided the entire study group into different age-subgroups. In addition, we took a variety of lag models into consideration. The results showed a strong connection between concentrations of fine particulate matter (PM2.5) and pediatric asthma hospital visits from 2009 to 2010 in Shanghai, China. For the entire study group, the greatest relative risk (RR) of PM2.5 on pediatric asthma hospital visits was 1.060 on a lag of 4 days. As for the three different age-subgroups, the greatest RR of PM2.5 on pediatric asthma hospital visits was 1.061 (at a lag of 5 days), 1.071 (at a lag of 4 days), and 1.052 (at a lag of 2 days), for the under-2-year-olds, 3-to-5-year-olds, and the 6-to-18-year-olds, respectively. The overall short-term effect of PM2.5 on pediatric asthma hospital visits was relatively stronger in younger children. Within the year, we detected the strongest seasonal effect of PM2.5 on pediatric asthma hospital visits in Summer. When adding other air pollutants in the analysis model, RR of PM2.5 on pediatric asthma hospital visits would be increased.

Influences of Extraction Methods on Physicochemical and Functional Characteristics of Three New Bulbil Starches from Dioscorea opposita Thunb. cv. Tiegun.

Starches from the bulbils of Dioscoreae opposita Thunb. cv. Tiegun were isolated by aqueous steeping (SBS), enzyme extraction (EBS), and alkaline extraction (ABS) methods, respectively. The physicochemical, mineral composition, thermal and morphological characteristics of these starches were investigated. The starch granules were oval, spherical and kidney-shaped and its crystal type is a mixture of A-type and B-type patterns. The starches having larger average granule size showed more amylose and phosphorus contents than those with smaller average granule size. Differential scanning calorimetry (DSC) showed that the SBS had an endothermic transition ranging from 65.8 °C to 76.3 °C with an enthalpy of 2.0 J/g. The endothermic transitions of ABS and EBS showed the regions of 67.9 °C to 73.0 °C, and 66.8 °C to 82.0 °C, respectively. The gelationization enthalpies of ABS and EBS were 13.8 and 11.5 J/g, respectively. Additionally, ABS presented greater clarity in comparison with EBS and SBS. Pasting properties indicated that ABS had the highest peak viscosity, breakdown, but SBS had the lowest trough, final viscosity, setback, and pasting temperature. Generally, ABS and EBS could be used as food thickener or frozen food additives. SBS and EBS were potential technological alternatives in quality preservation of frozen starch-based products and other industrial applications.

Prenylated Indole Diterpene Alkaloids from a Mine-Soil-Derived Tolypocladium sp.

Ten new prenylated indole diterpene alkaloids, tolypocladin A-J (1-10), including four chlorinated metabolites, have been isolated from a culture of a mine-soil-derived fungus, Tolypocladium sp. XL115. The structures and absolute configurations of 1-10 were determined by spectroscopic analysis, ECD calculations, and comparison with known compounds. Compounds 1 and 8 displayed significant antimicrobial activities. In addition, compound 1 also showed weak cytotoxic activity against all tested human cancer cell lines and suppressed the growth and viability of the patient-derived HCC cells T1224.

Chinese quince seed gum: Flow behaviour, thixotropy and viscoelasticity.

Characterization of the rheological properties of Chinese quince seed gum (CQSG) is fundamental when using it in food production. In the present paper, the chemical compositions and the rheological properties of CQSG at different concentrations, types of salts, temperatures and pH values were characterized by using shear or dynamic rheological experiments. The results demonstrated that uronic acid content of CQSG (31.7%) was high and different concentration CQSG solutions presented Newtonian plateaus followed by shear thinning regions. The viscosities of the gum solutions decreased with the addition of any salt, with increase in temperature and at extreme pH values (3 and 11). The stress and frequency sweep tests demonstrated a unique result in that the crossover frequency shifted to a higher value when the CQSG solution concentration increased. It is the basis for CQSG product development and quality control for its potential applications.

A Novel Antibiotic Mechanism of l-Cyclopropylalanine Blocking the Biosynthetic Pathway of Essential Amino Acid l-Leucine.

The unusual amino acid l-cyclopropylalanine was isolated from the mushroom Amanita virgineoides after detection in an anti-fungal screening test. l-Cyclopropylalanine was found to exhibit broad-spectrum inhibition against fungi and bacteria. The anti-fungal activity was found to be abolished in the presence of the amino acid l-leucine, but not any other amino acids, indicating that l-cyclopropylalanine may block the biosynthesis of the essential amino acid l-leucine, thereby inhibiting fungal and bacteria growth. Further biochemical studies found l-cyclopropylalanine indeed inhibits α-isopropylmalate synthase (α-IMPS), the enzyme that catalyzes the rate-limiting step in the biosynthetic pathway of l-leucine. Inhibition of essential l-leucine synthesis in fungal and bacteria organisms, a pathway absent in host organisms such as humans, may represent a novel antibiotic mechanism to counter the ever-increasing problem of drug resistance to existing antibiotics.

Inactivation and identification of three genes encoding glycosyltransferase required for biosynthesis of nogalamycin.

Nogalamycin is an anthracycline antitumor antibiotic, consisting of the aromatic aglycone attached with a nogalose and a nogalamine. At present, the biosynthesis pathway of nogalamycin, especially the glycosylation mechanism of the two deoxysugar moieties, had still not been extensively investigated in vivo. In this study, we inactivated the three glycotransferase genes in the nogalamycin-produced strain, and investigated the function of these genes by analyzing the metabolites profiles in the fermentation broth. The in-frame deletion of snogD and disruption of snogE abolished the production of nogalamycin completely, indicating that the gene products of snogD and snogE are essential to the biosynthesis of nogalamycin. On the other hand, in-frame deletion of snogZ does not abolish the production of nogalamycin, but production yield was reduced to 28% of the wild type, implying that snogZ gene may involved in the activation of other glycotransferases in nogalamycin biosynthesis. This study laid the foundation of modification of nogalamycin biosynthesis/production by genetic engineering methods.

Lycorine: a potential broad-spectrum agent against crop pathogenic fungi.

A screening test showed that lycorine exhibited significant antifungal activity against 24 pathogenic crop fungi at concentrations of 500 µg/ml and 100 µg/ml, respectively. Fusarium graminearum was selected for antifungal mechanism studies by observing its mycelial morphology and investigating the variations in its conductivity. In addition, the substance absorption and metabolism of F. graminearum were explored. The mechanism was revealed as being one by which lycorine destroyed the cellular membrane and further influenced substance absorption and cell metabolism.

Efficient bioconversion of quercetin into a novel glycoside by Streptomyces rimosus subsp. rimosus ATCC 10970.

Incubation of quercetin with Streptomyces rimosus subsp. rimosus ATCC 10970 yielded an unusual glycosylated derivative. The structure of the product was determined to be quercetin-7-O-ß-4″-deoxy-hex-4″-enopyranosiduronic acid based on the spectral data. Quercetin was completely converted into the glycoside in 72 h.