Inhibitory Effect of Fisetin on α-Glucosidase Activity: Kinetic and Molecular Docking Studies.

The inhibition of α-glucosidase is a clinical strategy for the treatment of type 2 diabetes mellitus (T2DM), and many natural plant ingredients have been reported to be effective in alleviating hyperglycemia by inhibiting α-glucosidase. In this study, the α-glucosidase inhibitory activity of fisetin extracted from Cotinus coggygria Scop. was evaluated in vitro. The results showed that fisetin exhibited strong inhibitory activity with an IC50 value of 4.099 × 10-4 mM. Enzyme kinetic analysis revealed that fisetin is a non-competitive inhibitor of α-glucosidase, with an inhibition constant value of 0.01065 ± 0.003255 mM. Moreover, fluorescence spectrometric measurements indicated the presence of only one binding site between fisetin and α-glucosidase, with a binding constant (lgKa) of 5.896 L·mol-1. Further molecular docking studies were performed to evaluate the interaction of fisetin with several residues close to the inactive site of α-glucosidase. These studies showed that the structure of the complex was maintained by Pi-Sigma and Pi-Pi stacked interactions. These findings illustrate that fisetin extracted from Cotinus coggygria Scop. is a promising therapeutic agent for the treatment of T2DM.

Characteristics of fish gelatin-anionic polysaccharide complexes and their applications in yoghurt: Rheology and tribology.

In this study, the rheological and tribological properties of complex solutions comprising of fish gelatin (FG)-Arabic gum (AG), FG-xanthan gum (XG), and FG-κ-carrageenan (κC), respectively, were measured, as well as the effects of the complex on the physical properties of yoghurt. Results showed that with increased XG and κC concentrations, the viscosity of FG-XG and FG-κC complex solutions both increased. It was also found that the lubrication properties of FG-anionic polysaccharide (AP) solutions decreased with the increased AP contents. The applications of FG-AP complexes (FG:AP = 9:1) improved firmness, water holding capacity and viscosity of yoghurt by the formation of large aggregates, but gels were easily destroyed at high frequency. Moreover, compared with gelatin, FG-AP complexes made yoghurt better lubrication properties during low and medium sliding speed, especially for FG-XG complexes. Thus, FG-AP complexes have the potential to be applied in producing yoghurt with good quality.

Heterogeneous and efficient transesterification of Jatropha curcas L. seed oil to produce biodiesel catalysed by nano-sized SO4 2-/TiO2.

Developing high-efficiency hetero-catalysts for transesterification reaction is of great importance in the production of biodiesel from Jatropha curcas L. seed oil (JO). Here, we synthesized a series of sulfated TiO2 by treating with varying H2SO4 concentration (SO4 2-/TiO2) and TiO2 catalysts and applied to the transesterification of JO. Furthermore, these heterostructures were characterized by many characterization methods including XRD, FT-IR, N2-adsorption, SEM, TEM, TG, py-IR and NH3-TPD, and their catalytic performance was investigated under various operating conditions. The results reveal that both the Brønsted and Lewis acid sites are presented in the SO4 2-/TiO2 catalysts, while only Lewis-type sites are observed in the TiO2 catalyst. And the acid intensity, surface area and mesoporous volume of catalysts are improved obviously after treating TiO2 with sulfuric acid. Then the SO4 2-/TiO2 catalysts exhibit much higher catalytic activity than TiO2 catalyst, which is attributed to the larger surface area and mesoporous volume and stronger acidity. Furthermore, the reusability behaviour of 1.5 SO4 2-/TiO2 catalyst in the transesterification of JO was also studied.

Carbazole alkaloids isolated from the branch and leaf extracts of Clausena lansium.

The present study carried out a phytochemical investigation of the methanol extract of the branches and leaves of Clausena lansium and afforded nine carbazole alkaloids (compounds 1-9) including two new carbazole alkaloids, claulansiums A and B (compounds 1 and 2). The new compounds were elucidated on the basis of extensive spectroscopic data (MS, NMR, IR, and UV) and the known compounds were identified by comparing spectroscopic data with those reported in literature. All the isolated compounds were tested for their cytotoxic activity against A549 and Hela cancer cell lines. Our results showed that compounds 2-6 exhibited varying degrees of cytotoxicity to cancer cells, with IC50 values ranging from 8.67 to 98.89 µmol·L-1.

Rheological behavior, emulsifying properties and structural characterization of phosphorylated fish gelatin.

Rheological, microstructural and emulsifying properties of fish gelatin phosphorylated using sodium trimetaphosphate (STMP) were studied. Phosphorylation was carried out at 50 °C for 0, 0.5, 1 or 2 h. Rheological behaviors indicated that phosphorylation decreased gelation rate constant (kgel) and apparent viscosity of gelatin solutions. Phosphorylation time was inversely proportional to tan δ; gelling and melting points of fish gelatin gels; however gel properties could be improved by short time of phosphorylation. Scanning electron microscopy and atomic force microscopy revealed that longer time of phosphorylation resulted in looser gel network with more aggregation. Longer phosphorylation time could stabilize fish gelatin emulsions, and endowed emulsions with smaller particle size and lower coefficient viscosity, but higher ζ-potential values. These results suggested that phosphorylation could be applied to obtain fish gelatin with varying functional properties suitable for numerous industrial applications.

Gelation kinetics and characterization of enzymatically enhanced fish scale gelatin-pectin coacervate.

BACKGROUND: Protein-polysaccharide complex coacervations have been considered extensively for the development of functional foods. The main problem of the complex coacervates is that they are highly unstable under different conditions and that cross-linking is necessary to stabilize them. In this study, the effects of pectin at different concentrations on the gel and structural properties of fish scale gelatin (FSG)-high methoxyl citrus pectin (HMP) coacervate enhanced by microbial transglutaminase (MTGase) were studied. RESULTS: The gelation rates and gel strength of the MTGase-enhanced FSG-HMP coacervate gels decreased with increasing HMP concentration. However, the enhanced coacervate gels exhibited better thermal behavior and mechanical properties compared with the original gels. Also, TG-P8 exhibited the highest melting point (27.15 ± 0.12 °C), gelation point (15.65 ± 0.01 °C) and stress (15.36 ± 0.48 kPa) as HMP was 8 g kg-1 . Particle size distribution, fluorescence emission and UV absorbance spectra indicated that MTGase and HMP could make FSG form large aggregates. Moreover, confocal laser scanning microscopy of treated coacervate gels showed a continuous protein phase at low HMP concentrations. CONCLUSION: FSG and HMP could form soluble coacervate, and MTGase could improve the thermal and mechanical properties of coacervate gels. © 2017 Society of Chemical Industry.

Comparison of rheological behaviors and nanostructure of bighead carp scales gelatin modified by different modification methods.

In this study, microbial transglutaminase (MTGase) and pectin were compared to modify bighead carp (Hypophthalmichthys nobilis) scale gelatin. The functional properties of modified fish scales gelatin (FSG) were largely improved, including melting temperature and rheological behavior. While, modification methods decreased the triple-helix content and destroyed the single left-hand helix chain of modified FSG as investigated by X-ray diffraction. MTGase could induce the denser and finer gels network, but had none significant effect on nanostructural properties of fish gelatin. Pectin inserted itself into the fish gelatin gels network and caused aggregations, forming crystalline peaks and various nanostructures. In particular, compared with pectin modified FSG, MTGase produced FSG with lower storage modulus and apparent viscosity, but higher gel points and melting points.

Pectin and enzyme complex modified fish scales gelatin: Rheological behavior, gel properties and nanostructure.

The rheological behavior, gel properties and nanostructure of complex modified fish scales gelatin (FSG) by pectin and microbial transglutaminase (MTGase) were investigated. The findings suggested that MTGase and pectin have positive effect on the gelation point, melting point, apparent viscosity and gel properties of FSG. The highest values of gel strength and melting temperature could be observed at 0.8% (w/v) pectin. Nevertheless, at highest pectin concentration (1.6% w/v), the gel strength and melting temperature of complex modified gelatin gels decreased. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analysis revealed that MTGase catalyzed cross-links among soluble fish scales gelatin - pectin complexes, which could be responsible for the observed increase in rheological behavior, gel strength and melting temperature of modified complex gels.

De Novo Transcriptome Assembly and Annotation of the Leaves and Callus of Cyclocarya Paliurus (Bata1) Iljinskaja.

Cyclocarya Paliurus (Bata1) Iljinskaja contains various bioactive secondary metabolites especially in leaves, such as triterpenes, flavonoids, polysaccharides and alkaloids, and its leaves are widely used as an hyperglycemic tea in China. In the present paper, we sequenced the transcriptome of the leaves and callus of Cyclocarya Paliurus using Illumina Hiseq 4000 platform. After sequencing and de novo assembly, a total of 65,654 unigenes were generated with an N50 length of 1,244bp. Among them, 35,041 (53.37%) unigenes were annotated in NCBI Non-Redundant database, 19,453 (29.63%) unigenes were classified into Gene Ontology (GO) database, and 7,259 (11.06%) unigenes were assigned to Clusters of Orthologous Group (COG) categories. Furthermore, 11,697 (17.81%) unigenes were mapped onto 335 pathways in Kyoto Encyclopedia of Genes and Genomes (KEGG), among which 1,312 unigenes were identified to be involved in biosynthesis of secondary metabolites. In addition, a total of 11,247 putative simple sequence repeats (SSRs) were detected. This transcriptome dataset provides a comprehensive sequence resource for gene expression profiling, genetic diversity, evolution and further molecular genetics research on Cyclocarya Paliurus.

Production of chlorogenic acid and its derivatives in hairy root cultures of Stevia rebaudiana.

Chlorogenic acid and its derivatives (CADs) are valuable bioactive plant secondary metabolites with many health benefits. In the present study, Stevia rebaudiana hairy root cultures were established, and the culture conditions for the production of CADs were optimized. The hairy roots were induced by coculture of S. rebaudiana leaves and Agrobacterium rhizogenes (C58C1) after infection, which were further verified by PCR detection of rolB and rolC genes. HPLC-MS and HPLC analysis showed that chlorogenic acid (3-caffeoylquinic acid, 3-CQA), 3,5-dicaffeoylquinic acid (3,5-CQA), and 4,5-dicaffeoylquinic acid (4,5-CQA) were the major CADs in the hairy roots. Eight single roots with rapid growth rate were selected. Among them, T3 had the highest yield of CADs. B5 medium supplemented with 40 g/L sucrose was more suitable for the production of CADs than others. Under optimal culture conditions, the total content of these three compounds reached 105.58 mg/g and total yield was 234.40 mg/100 mL.

Structure selective complexation of cyclodextrins with five polyphenols investigated by capillary electrokinetic chromatography.

The complexation of five polyphenols, namely trans-resveratrol, astilbin, taxifolin, ferulic acid, and syringic acid (guest molecules) with α-, ß-, and γ-cyclodextrin (host molecules), was investigated by capillary electrokinetic chromatography. The binding constants were calculated based on the effective electrophoretic mobility change of guests with the addition of cyclodextrins into the background electrolyte. Because of cavity size, cyclodextrins showed structure-selective complexation property to different guest. The stability of the trans-resveratrol complexes was in the order of ß- > α- > γ-cyclodextrin. The cavity size of α-cyclodextrin was too small for astilbin and taxifolin molecules, and thus they could not form complexes. The molecular size of syringic acid was too big for all cyclodextrins cavity, and no cyclodextrin could form complexes with it. Temperature studies showed that the binding constants decreased with the rise of temperature. Enthalpy and entropy values were calculated and the negative values of these parameters indicated that the complexation process was enthalpy-controlled. Van der Waals force and release of high-enthalpy water molecules from the cyclodextrins cavity played important roles in the process.

Association of porcine IGF binding protein-5 gene with meat quality.

IGFBP-5 is a member of the IGF families. Using PCR-SSCP, genotypic and allelic frequencies were analyzed in 18 pig breeds (n = 600). The association between haplotypes and production performance was analyzed in a Jinhua x Pietrain population family (n = 212, total 24 traits). Two SNPs (T199C and G485A) within the gene were analyzed. The breeds had different genotypic and allelic frequencies. Typically, the Chinese native pig breeds carried a higher allele C and G frequency (over 50%) than those of the European pigs, and only Guangdong Large White and wild boar were at Hardy-Weinberg equilibrium. The pigs carrying the CG haplotype had higher hue, loin, and thigh pH1 values than pigs with the TA haplotype, and pigs with the TA haplotype had the lowest loin pH2 value and highest color-a value among the haplotypes. It is proposed that the IGFBP-5 gene is associated with the variation in meat quality, especially in pH value together with other QTLs on chromosome 15.

Dimethyl [(4-fluoro-phen-yl)(6-methoxy-benzothia-zol-2-ylamino)meth-yl]phospho-nate.

In the mol-ecule of title compound, C(17)H(18)FN(2)O(4)PS, both the benzene ring with its conjunction C atom and the benzothia-zole ring with its conjunction N atom are close to planar (the maximum deviations are 0.0267 and 0.0427 Šfor the benzene and benzothiazole rings, respectively), the dihedral angle between the planes of the benzothia-zole and benzene rings is 119.05 (3)°. The mol-ecular packing is stabilized by inter-molecular N-H⋯O, C-H⋯N and C-H⋯F hydrogen bonding, and by C-H⋯π and π-π stacking inter-actions [centroid-centroid distances = 2.99 (2), 2.96 (3), 2.88 (2) and 3.773 (4) Å].

[Research progresses on nutrigenomics].

Nutrition science is an age-old subject, and offers important theoretic instructions for human health protection and disease prevention. With the development of molecular biology, it will be a key technique in the 21 century. Combination of molecular biology and nutrition, bio-nutrition is formed. While the combination of genome and nutrition, nutrigenomics is developed. Nutrigenomics covers a wide range of areas, which studies the interactive effects between nutrients and genes expression, and predicts the expressive response to the nutrients. Genomics technology can help us to identify some dis-ease-related genes, thereby people establish individual diet and make their heath attained the best status through adjusting diet. This paper focuses on the main research technology of nutrigenomics and its application.

Antioxidative activity of hen egg ovalbumin hydrolysates.

To evaluate the antioxidative activity of the hydrolysates of ovalbumin, the antioxidative activities of the enzymatic extracts were evaluated using three different methodologies scavenging assays such as superoxide anion, hydroxyl radical, and inhibitory oxidation of linoleic acid in vitro, and the activities of SOD, GSH-PX, CAT and the level of MDA were determined in serum and liver of aged mice induced by G-gal. The results showed that the hydrolysates had a distinctly inhibitory action to superoxide anion made by alkaline pyrogallic acid, HO. produced by Fenton reaction, the oxidation of linoleic acid in linoleic acid autoxidation system, and presented a positive correlation. The inhibition capacity of hydrolysates against superoxide anion and HO. were more than 45% and 56% respectively at the concentration 5 mg/mL. And the hydrolysates could significantly (p< 0.01) prevented the activities of SOD, GSH-Px, and CAT against reducing and all three concentrations could significantly (p< 0.01) decrease the MDA contents in the serum and liver of aged mice induced by G-gal. The antioxidative activity of high concentration was similar to that of control group.