Synthesis, characterization, and biological activity of selenium nanoparticles conjugated with polysaccharides.

Nanoparticles with unique properties have potential applications in food, medicine, pharmacology, and agriculture industries. Accordingly, many significant researches have been conducted to develop novel nanoparticles using chemical and biological techniques. This review focuses on the synthesis of selenium nanoparticles (SeNPs) using polysaccharides as templates. Various instrumental techniques being used to confirm the formation of polysaccharide-SeNPs conjugates and characterize the properties of nanoparticles are also introduced. Finally, the biological activities of the synthesized SeNPs and the influence of structural factors of polysaccharides on the property of synthetic nanocomposites are highlighted. In general, the polysaccharides functionalized SeNPs can be easily obtained using sodium selenite as precursor and ascorbic acid as reductant. The final products having different particle size, morphology, and selenium content exhibit abundant physiological activities. Structural factors of polysacchairdes involving molecular weights, substitution of functional groups, and chain conformation play determinant roles on the properties of nanocomposites, resulting in different biological performances. The review on the achievements and current status of polysaccharides conjugated SeNPs provides insights into this exciting research topic for further studies in the future.

Preparation and evaluation of a sustained-release buckwheat noodle.

BACKGROUND: Different carbohydrates elicit various effects on the digestibility and the glucose release rate, so it is of interest to develop a sustained-release noodle based on the combination of different carbohydrates and reveal the sustained-release mechanism. RESULTS: The data obtained suggest that xanthan and konjac gum exhibited excellent and synergistic sustained-release properties, whereas cornstarch showed the lowest average digestion rate. The sustained release was particularly evident when the noodle consisted of the following components: 50 g of 25 g kg(-1) hydrophilic colloid mixture solution composed of a 1:1 mass ratio of xanthan:konjac gum and 100 g of reconstructed flour consisting of 200 g kg(-1) buckwheat flour, 400 g kg(-1) cornstarch, and 400 g kg(-1) plain flour. The morphological structure of noodles revealed that the composite hydrophilic colloids strengthened the interaction between the gluten network and starch granules. This buried starch within the three-dimensional structure thereby releasing glucose in a slow and sustained way. The most suitable model to describe glucose release from noodles was the Ritger-Peppas equation, which revealed that matrix erosion contributed to the release mechanism. CONCLUSION: These findings indicate that the controlled use of hydrophilic colloids and starches in manufacturing noodles could modulate the glucose sustained-release. © 2015 Society of Chemical Industry.

Purification and characterisation of a glutamic acid-containing peptide with calcium-binding capacity from whey protein hydrolysate.

The bioavailability of dietary ionised calcium is affected by intestinal basic environment. Calcium-binding peptides can form complexes with calcium to improve its absorption and bioavailability. The aim of this study was focused on isolation and characterisation of a calcium-binding peptide from whey protein hydrolysates. Whey protein was hydrolysed using Flavourzyme and Protamex with substrate to enzyme ratio of 25:1 (w/w) at 49 °C for 7 h. The calcium-binding peptide was isolated by DEAE anion-exchange chromatography, Sephadex G-25 gel filtration and reversed phase high-performance liquid chromatography (RP-HPLC). A purified peptide of molecular mass 204 Da with strong calcium binding ability was identified on chromatography/electrospray ionisation (LC/ESI) tandem mass spectrum to be Glu-Gly (EG) after analysis and alignment in database. The calcium binding capacity of EG reached 67·81 µg/mg, and the amount increased by 95% compared with whey protein hydrolysate complex. The UV and infrared spectrometer analysis demonstrated that the principal sites of calcium-binding corresponded to the carboxyl groups and carbonyl groups of glutamic acid. In addition, the amino group and peptide amino are also the related groups in the interaction between EG and calcium ion. Meanwhile, the sequestered calcium percentage experiment has proved that EG-Ca is significantly more stable than CaCl2 in human gastrointestinal tract in vitro. The findings suggest that the purified dipeptide has the potential to be used as ion-binding ingredient in dietary supplements.

1,3-Bis(2-nitro-phen-oxy)propan-2-ol.

In the title compound, C(15)H(14)N(2)O(7), the planes of the two benzene rings form a dihedral angle of 33.16 (17)°. In the crystal, inter-molecular hydrogen bonds involveing the OH group and nitro O atoms link the mol-ecules into chains propagating along the a axis.

Highly Efficient Deamidation of Wheat Gluten by Glucose-Citric Acid-Based Natural Deep Eutectic Solvent: A Potential Effective Reaction Media.

An efficient technique using citric acid and glucose based natural deep eutectic solvent (G-C-NADES) was developed to obtain ultrahigh deamidated wheat gluten (UDWG) (deamidation degree (DD) > 90%). FTIR and 1H NMR indicated intensive hydrogen bonds (HBs) in G-C-NADES supermolecules. Quantum chemical calculations and molecular dynamic simulations demonstrated that 10 wt % diluted G-C-NADES still had a myriad of HBs. Physicochemical results showed UDWG had DD up to 92.45% after G-C-NADES deamidation, that is, 22% higher than citric-acid-DWG with a weak degree of hydrolysis (1.75%). Conformational characterization demonstrated the obvious conversion from α-helix to ß-sheet via FTIR, the least amount of disulfide bonds by Raman spectra, and more exposure of tryptophan residues by fluorescence measurement for UDWG. It is proven that enhanced accessible conformation of WG reached with HBs of G-C-NADESs could contribute to the improvement on nucleophilic attack of deamidation, declaring that G-C-NADES might be a potential solvent for obtaining an ultrahigh deamidation for WG to successfully guarantee the safety of wheat gluten based cereal food regarding to lowering its allergy.

Improved stabilization of coix seed oil in a nanocage-coating framework based on gliadin-carboxymethyl chitosan-Ca2.

Coix seed oil (CSO) is easily suffered functional-loss by oxidation and hydrothermal-treatment. The environmental stable nanocage-coating-CSO particles (OGC-Ca) by the frameworks consist of gliadins, carboxymethyl chitosan (CMCS) and Ca2+ were investigated. Results showed Ca2+ was the key controller for fabricating this nanocage-coating-frameworks, bridging macromolecule-chains with electrostatic interaction and hydrogen bonds, detected by FTIR, CD, DSC and XRD. SEM displayed new-formed velvet-like twigs after cross-linking CMCS to gliadins. Ca2+ assisted the nanocage-coating by significant down-sizing conversion OGC to OGC-Ca with consumption of twigs. OGC-Ca displayed a good stability towards heat (60-80 °C, 0-80 min), pH (3-8), NaCl (0-0.5 mM), storage (4/25 °C, 12 days), and a reduce of the pre-oxidation value of CSO in water and the improved controlled release of CSO in simulated GI tract. It illustrated GC-Ca frameworks would be a suitable delivery carrier for the CSO like pharmaceuticals and nutraceuticals for the food or medical use.

Copper(I)-Catalyzed Nitrile-Addition/N-Arylation Ring-Closure Cascade: Synthesis of 5,11-Dihydro-6H-indolo[3,2-c]quinolin-6-ones as Potent Topoisomerase-I Inhibitors.

In this paper, we present a copper(I)-catalyzed nitrile-addition/N-arylation ring-closure cascade for the synthesis of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones from 2-(2-bromophenyl)-N-(2-cyanophenyl)acetamides. Using CuBr and t-BuONa in dimethylformamide (DMF) as the optimal reaction conditions, the cascade reaction gave the target products, in high yields, with a good substrate scope. Application of the cascade reaction was demonstrated on the concise total syntheses of alkaloid isocryptolepine. Further optimization of the products from the cascade reaction led to 3-chloro-5,12-bis[2-(dimethylamino)ethyl]-5,12-dihydro-6H-[1,3]dioxolo[4',5':5,6]indolo[3,2-c]quinolin-6-one (2k), which exhibited the characteristic DNA topoisomerase-I inhibitory mechanism of action with potent in vitro anticancer activity. Compound 2k actively inhibited ARC-111- and SN-38-resistant HCT-116 cells and showed in vivo activity in mice bearing human HCT-116 and SJCRH30 xenografts. The interaction of 2k with the Top-DNA cleavable complex was revealed by docking simulations to guide the future optimization of 5,11-dihydro-6H-indolo[3,2-c]quinolin-6-ones as topoisomerase-I inhibitors.

Comparative study on glucomannans with different structural characteristics: Functional properties and intestinal production of short chain fatty acids.

Glucomannans (GMs) from abundant natural resources have excellent processing properties and plentiful bioactivities. In current study, functional properties of GMs with different structural characteristics, including KGM from konjac, DOP from dendrobium, AGP40, ASP-4N, ASP-6N, & ASP-8N from aloe were determined. Results suggested that molecular weights (Mw) of GMs were positively correlated with their water absorption capacity, fat absorption capacity, and viscosity, while ratio of mannose/glucose showed negative effect. Higher degree of acetylation (DA) mainly corresponded to higher values of solubility and ζ-potential. Then, effects of the six GMs on general health status, serum biochemicals, and intestinal SCFAs production in mice were evaluated in vivo. Analysis of general health status and levels of serum biochemicals revealed that mice with consecutive supplementation of GMs for 14 days performed normally compared with those in control group. Interestingly, the productions of SCFAs (mainly acetate and butyrate) in the cecal and colonic contents were significantly promoted. Generally, higher concentrations of SCFAs were produced when mice were treated with GMs having higher Mw, ratio of glucose, and DA. The current investigation suggested that both functional and intestinal fermentation property of GMs were jointly determined by the monosaccharide composition, molecular weight, and degree of acetylation.

Protuboxepin C and protuboxepin D from the sponge-derived fungus Aspergillus sp SCSIO XWS02F40.

Two new diketopiperazine alkaloids, named protuboxepin C (1) and protuboxepin D (2), which contain D-Phe residue and oxepin ring, were isolated from EtOAc extract of sponge-derived fungus Aspergillus sp SCSIO XWS02F40. Their structures were elucidated by 1D, 2D NMR and HRESIMS dates, and their absolute configurations were confirmed by single crystal X-ray diffraction experiments and CD analyses. The in vitro cytotoxicity of these two new compounds was further evaluated using A549 and Hela cell lines.

Risk of glomerular filtration rate decline in patients with hypertrophic cardiomyopathy and obstructive sleep apnoea.

Sleep apnoea is associated with chronic kidney diseases. A high obstructive sleep apnoea (OSA) prevalence is shown in patients with hypertrophic cardiomyopathy (HCM). Whether the presence of OSA would affect the renal function of patients with HCM is unknown. Forty-five consecutive patients with HCM were divided into the HCM OSA- and OSA+ groups. Forty-three patients with OSA without HCM were recruited as controls. Clinical indices, including estimated glomerular filtration rate (eGFR) and urine 8-hydroxy-2-deoxyguanosine (8-OHdG), were measured. The eGFR was significantly lower in the HCM OSA+ group than in the HCM OSA- (P < 0.05) and OSA (P < 0.001) groups. Multivariate linear regression analysis identified that the apnoea-hypopnoea index was independently associated with eGFR in all patients with HCM (ß = -1.329, 95% confidence interval: -1.942, -0.717, P < 0.001). The urine 8-OHdG level, an oxidative stress marker, was significantly higher in the HCM OSA+ group than in the HCM OSA- (P < 0.001) and OSA (P < 0.001) groups and significantly correlated with the AHI (r = 0.467, P = 0.003) and eGFR (r = -0.457, P = 0.004) in all patients with HCM. Our study suggests a risk of eGFR decline in patients with HCM and OSA.

Purification and characterization of a novel lectin from Chinese leek seeds.

A novel lectin, CLSL, was purified from Chinese leek seeds by ion exchange chromatography on SP Sephadex C-25 and gel filtration chromatography on Sephadex G50. The lectin had a molecular weight of 23.6 kDa and was composed of two identical subunits linked by disulfide bonds, a conclusion based on SDS-PAGE under reducing and nonreducing conditions. CLSL was a glycoprotein with a carbohydrate content of 3.6%. It exerted potent agglutinating activity against rat red blood cells at a concentration of 8.9 µg/mL. Hemagglutination of rat erythrocytes was inhibited by d-fructose, mannitol, and sorbose at the concentration of 20 mM. The hemagglutinating activity of CLSL was maintained at 100 °C for 60 min and under acidic pH conditions but was lost at neutral and alkaline pH conditions. The hemagglutinating activity was stimulated by Ca(2+), Fe(2+), and Cu(2+) but inactivated by Ba(2+) at a concentration of 10 mM. Ba(2+)-mediated inactivation of CLSL was caused by CLSL conformational change induced by barium ions, according to the results of circular dichroism and fluorescence spectroscopy. Deconvolution of the CLSL circular dichroism indicated that it was an α-helical lectin with α-helix and ß-fold contents of 35.8% and 8.6%, respectively. CLSL could also selectively inhibit cell proliferation.

A non-specific lipid transfer protein with antifungal and antibacterial activities from the mung bean.

A non-specific lipid transfer peptide (nsLTP) with antimicrobial activity was isolated from the mung bean (Phaseolus mungo) seeds. The procedure entailed aqueous extraction, ion exchange chromatography on CM-Sephadex and high performance liquid chromatography (HPLC) on POROS-HS-20. The peptide exhibited a molecular mass of 9.03 kDa in mass spectrometry. It exerted antifungal action toward Fusarium solani, Fusarium oxysporum, Pythium aphanidermatum and Sclerotium rolfsii, and antibacterial action against Staphylococcus aureus but not against Salmonella typhimurium. The lipid binding of this peptide was very similar to that of a previously described lipid transfer protein extracted from wheat seeds and maize seeds, indicating that it possessed lipid transfer activity. The present findings add to the scarcity of the literature on leguminous nsLTPs.

[Ultrastructure of Ericerus pela (Chavannes) nymph mouthparts and ecological adaptations].

The ultrastructure of nymph mouthparts of the Chinese white wax scale (CWWS), Ericerus pela, consists internally of the crumena, tentorium, the stylet bundle, comprised of two mandibular stylets and two maxillary stylets, and the external clypeolabral shield, labium and sensilla. The mouthpart morphology and structures of the female nymphs are similar to the male. The mouthparts of CWWS have significantly different features in comparison to aphids and other coccids. First, the mouthparts of CWWS have a crumena and a developed tentorium. Second, the labrum is highly degraded and the labium is short and one-segmented. Third, the maxillary stylets have two 'T' type locks. Lastly, the hairs of the mouthpart are sparse and the sensilla are simple. As the labrum and labium of CWWS displayed a high degree of degradation and the tentorium was found to be highly developed, the stretching of the stylet bundle was considered to be controlled by the tentorium and crumena together. Furthermore, the degraded sensilla may be related to a specialization of feeding behavior. There were no significant differences in the length and diameter of the stylet bundles between the female and male. However, the length and diameter of the stylet bundles were significantly different between the first instar nymphs and the second instar nymphs. The first instar nymphs had stylet fascicles that were shorter and soft and initially lived on the leaves of the host trees, presumably because the leaves were thinner and they were able to pierce the leaves while the stylet bundle was relatively soft. However, the second instar nymphs had stylet bundles that were relatively hard. After the numphs molted, the degree of ossification of the stylet bundles was enhanced (increased) and the nymphs returned to the branches for living, where the strengthened stylet bundles may provide a better adaption for the thicker bark. All told, the first and second stage instar CWWS nymphs switched from leaves to the branches in order to find a safe habitat and stable food source.

[Effects of host plants on natural population of Kerria yunnanensis (Hemipterae: Kerridae)].

The study on the development, survivorship and reproduction of Kerria yunnanensis on 4 kinds of host trees indicated that in natural environment, the initial K. yunnanensis population density varied from 181.17 individuals on Dalbergia obtusifolia to 145.27 individuals on Ficus facemosa per cm2, realized sex ratio varied from 0.24 on D. obtusifolia and F. cunia to 0.19 on D. balansae, accumulated population mortality from larval to adult varied from 90.03% on D. balansae to 87.05% on F. cunia, and development period from larval to adult ranged from 156 days on D. balansae to 140 days on F. facemosa. The oviposition of K. yunnanensis varied from 536 eggs on D. balansae to 345.86 eggs on F. facemosa, female adult mass varied from 12.62 mg on D. balansae to 9.03 mg on F. cunia, and basic reproduction rate varied from 48.51 on D. balansae to 32.79 on F. facemosa. D. balansae was the most suitable host plant for K. chinensis summer life cycle.

Crystallization and preliminary X-ray crystallographic analysis of a non-specific lipid-transfer protein with antipathogenic activity from Phaseolus mungo.

A 9 kDa non-specific lipid-transfer protein (nsLTP) from mung bean (Phaseolus mungo) seeds, displaying antifungal activity, antibacterial activity and lipid-transfer activity, was crystallized at 297 K using ammonium sulfate as a precipitant by means of the hanging-drop vapour-diffusion method. Native X-ray diffraction data were collected to a resolution of 2.4 A. The crystals are rhombohedral, belonging to space group P2(1)2(1)2(1), with unit-cell parameters a = 38.671, b = 51.785, c = 55.925 A. Assuming the presence of one molecule in the crystallographic asymmetric unit results in a Matthews coefficient (V(M)) of approximately 3.0 A(3) Da(-1), corresponding to a solvent content of about 58%.