Cranberry derived proanthocyanidins can prevent pathogen invasion of kidney epithelial cells

The in vitro effectivity of cranberry derived proanthocyanidins (PACs) for the mitigation of kidney cell infection by selected uro- and entero-pathogens is examined with an adhesion/invasion assay and confocal microscopy. This study demonstrates that PACs effectively reduce invasion of canine kidney cells by pathogenic bacteria: Escherichia coli CFT073 and O157:H7, Enterococcus faecalis 29212, and Pseudomonas aeruginosa 10145. These effects demonstrate the potential for cranberry derived PACs as a useful tool in the prevention of kidney infection.     

米胚芽中胰脂肪酶抑制剂的分离纯化

由米胚芽中提取的胰脂肪酶抑制剂经鉴定主要为蛋白质.通过硫酸铵分级沉淀(40%～80%)、凝胶层析(Sephadex G-75)对米胚芽水溶物进行分离纯化.所得的洗脱峰I和洗脱峰Ⅱ的组分进行高效液相色谱分析,测定了胰脂肪酶活性抑制率较高的组分的分子量,分别为125KD和21KD.     

Cabernet Sauvignon wines from two different clones, characterization and evolution during bottle ageing

Phenolic compounds constitute important quality parameters of wines. Wines produced from different clones of the same grape variety show differences in relation to their chemical composition. The aim of this study was to characterize and differentiate Cabernet Sauvignon wines from two clones in relation to their chemical composition and to examine changes in the phenolic composition and antioxidant activity during wine ageing in the bottle. All wines were produced with Cabernet Sauvignon grapes, clones 685 and 169, from two vineyards, under the same microvinification conditions. The wines were characterized in relation to phenolic composition and antioxidant activity, as well as monitored over 11 months of bottle ageing. A significant difference was observed between the chemical compositions of the wines produced from clones 169 and 685, clone 169 showing the highest phenolic content while clone 685 had better color characteristics. The wines showed high antioxidant activity. Principal components and cluster analyses demonstrated separation of the wine according to the clone. In relation to wine bottle ageing, for both clones evaluated was observed a decrease in all phenolic compound, except of quercetin, and the antioxidant activity of these wines increased during storage.     

Purification and characterization of antioxidative peptides derived from rice bran protein hydrolysates

Rice bran protein fraction (RBPF)—albumin, globulin, glutelin and prolamin were hydrolyzed with proteases M, N, P, S and pepsin under their optimal conditions for 24 h. Hydrolysates of various hydrolysis periods were collected and subjected to peptide mapping and the antioxidative activity measured by the 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic Acid (ABTS) method. Protease M hydrolysates showed high degree of hydrolysis (DH), but low antioxidative activity. On the contrary, pepsin hydrolysates showed low DH with high activity. Albumin and globulin hydrolysates had higher DH values, but lower values for glutelin and prolamin. The globulin hydrolysate (Opep2) from 2 h-pepsin hydrolysis was separated by using three consecutive purification steps with RP-HPLC. Nineteen antioxidative peptides were isolated and their amino acid sequences were determined by a gas-phase protein sequencer and MALDI-TOF mass spectrometry. These peptides were composed of 6–30 amino acid residues with molecular masses ranging from 670–3,611 Da. Tyr-Leu-Ala-Gly-Met-Asn had the highest antioxidative activity among them.     

Production and physicochemical characterization of resistant starch type III derived from pea starch

Smooth pea starch was used for the production of physiological important resistant starch type III. For reduction of the molecular weight of the starch, different strategies including enzymatic debranching and acid hydrolysis (lintnerization), were tested to obtain an optimal starting material for retrogradation. The resulting polymer chain lengths were analyzed by high-performance anion-exchange chromatography. Temperature regimes and starch concentrations in gel were optimized during the retrogradation with the aim to obtain a high yield of resistant starch. Optimal conditions led to resistant starch contents up to 74%. The products were thermostable and showed no loss of resistant structures after autoclaving. The peak temperatures of the thermal transition were at approximately 147 degrees C. The resulting resistant starch products are suitable for the generation of functional foods.     

Recombinant expression and characterization of N-acetylglucosaminyltransferase I derived from Nicotiana tabacum

The C-terminal catalytic domain of tobacco N-acetylglucosaminyltransferase I fused to maltose-binding protein was produced in Escherichia coli as a soluble form with significant activity. The protein was affinity-purified using amylose resin, and its enzymatic properties were investigated, including its divalent cation requirements, optimal temperature, optimal pH, and substrate specificity.     

Purification and characterization of rat alpha-lactalbumins: apparent genetic variants

Rat alpha-lactalbumin, from the milk of Fischer 344 (CDF) rats, was isolated and purified by a combination of gel filtration and diethylaminoethyl-cellulose ion exchange chromatography. Three electrophoretically distinct proteins had alpha-lactalbumin activity. Staining for carbohydrate indicated that at least two of the three forms were glycoproteins. The low molecular weight protein fraction from the wheys of two additional strains of laboratory rat were compared to ascertain whether the composition of this fraction was common in the divergent strains. Outbred Wistar and Long-Evans dams yielded wheys containing up to six forms of alpha-lactalbumin. Either one or both of two groups of three alpha-lactalbumins were in a given milk sample. The two groups of three alpha-lactalbumins appear to represent two genetic variants upon which is imposed a polymorphic character. All forms of alpha-lactalbumin, within and between strains, were immunologically identical.     

Purification and characterization of antioxidative peptide derived from muscle of conger eel (Conger myriaster)

The tryptic hydrolysate of conger eel (Conger myriaster) muscle protein was fractionated according to the molecular weights using ultrafiltration (UF) membrane system. The lowest molecular weight fraction (<1 kDa) with higher antioxidative properties was purified using consecutive chromatographic techniques and designated conger eel antioxidative peptide (CEAP). Sequence determination revealed that it contained nine amino acids in its sequence (LGLNGDDVN) and the molecular mass was identified to be 928 Da. CEAP performed better than the natural antioxidant, α-tocopherol for the prevention of lipid peroxidation in vitro. Additionally, it scavenged hydroxyl radicals and carbon-centered radicals at IC₅₀ values of 74.1 μM and 78.5 μM, respectively. Therefore these results suggested that the peptides derived from conger eel protein hydrolysates are responsible for higher antioxidative properties and molecular weight as well as presence of hydrophobic amino acids highly contributed for their antioxidation.     

Growth and adhesion of osteoblast-like cells derived from neonatal rat calvaria on calcium phosphate ceramics

The effects of biocompatible ceramics on the growth and adhesion of osteoblast-rich rat calvarial cell cultures were investigated. Osteoblast-like cells and mouse fibroblast-like L-929 cells were cultured on composite sinters of hydroxyapatite (HAP) and beta-tricalcium phosphate (TCP) culture carriers, whose Ca/P molar ratios were adjusted to values of 1.50, 1.55, 1.60, 1.64 and 1.67. The growth rates of both cell types were accelerated on the TCP-HAP ceramics as compared to those on polystyrene plastic (LUX) or bioinert zirconia ceramics. The population of osteoblast-like cells reached a density of 2.28 x 10(5) cells/cm2 on 100% HAP (Ca/P ratio 1.67) at 9 d of culture, while the corresponding cell density was 1.66 x 10(5) cells/cm2 on LUX and 1.26 x 10(5) cells/cm2 on zirconia. Adhesion of the osteoblast-like cells on TCP-HAP ceramics was similarly increased as compared with that on LUX or zirconia ceramics. The adhesion of L-929 cells on TCP-HAP ceramics was found to be weaker than that on cultures on LUX or zirconia ceramics. The time-dependent variations in the alkaline phosphatase activity of the osteoblast-like cells showed that the osteoblastic phenotype was potentiated by culturing the cells in calcium-rich media. The surface analyses of the Ca/P ratio and the microstructure by XRD and FTIR suggest that the Ca-rich surface was newly formed by recombination on the surface layer in the culture medium containing fetal bovine serum. These results suggest that the surface of TCP-HAP ceramics, especially that of 100% HAP ceramics, are effective for accelerating growth and differentiation of osteoblast-like cells. This is most probably due to the chemical and physical instability and composition of 100% HAP, which promote the formation of a Ca-rich layer at the cell-material interface and provision of Ca ions to the osteoblast-like cells.     

Manufacture and characterization of gelatin films derived from beef,pork and fish sources using twin screw extrusion

Gelatin films derived from beef, pork and fish sources were manufactured by twin-screw, co-rotating extrusion. The effect of extrusion processing parameters, namely; screw speed (100–400 rpm) and temperature (90, 90, 90, 90 °C and 90, 120, 90, 90 °C) on the mechanical and barrier properties of gelatin films were studied. Increasing screw speed up to 300 rpm improved (P < 0.05) tensile strength (TS) and reduced (non-significantly) water vapour permeability (WVP) values for all manufactured gelatin films. However, the WVP of various gelatin film types was reduced (P < 0.05) when a screw speed of 400 rpm was employed. Increasing the speed of extrusion promoted (P < 0.05) increased solubility of films in water. Manufacture of films using a higher temperature profile resulted in films possessing higher puncture strengths (PS), increased water barrier properties with higher water solubility.     

Epigenetic toxicity of hydroxylated biphenyls and hydroxylated polychlorinated biphenyls on normal rat liver epithelial cells

2-Biphenylol, 3-biphenylol, 2,2'-biphenyldiol, 3,3'-biphenyldiol, 3-chloro-2-biphenylol, and 4,4'-dichloro-3-biphenylol were evaluated using the scrape-loading/dye transfer (SL/ DT) technique to determine in vitro gap junctional intercellular communication (GJIC) in a normal rat liver epithelial cell line as a measure of the epigenetic toxicity. Cytotoxicity was determined using the neutral red uptake assay. A dose range of 0-300 microM was examined. Only 3,3'-biphenyldiol and 4,4'-dichloro-3-biphenylol induced cytotoxicity within the tested dose ranges. Noncytotoxic doses were selected for evaluation of epigenetic toxicity. 4,4'-Dichloro-3-biphenylol was most inhibitory to GJIC at the lowest dose. The cytotoxicity and GJIC inhibitory effects observed for 4,4'-dichloro-3-biphenylol might be, although not exclusively, a consequence of the lipophilic nature of this chemical. 3-Chloro-2-biphenylol was least inhibitory to GJIC. 3-Chloro-2-biphenylol was less inhibitory to GJIC than 2-biphenylol because of the presence of the chlorine functional group, which appears to attenuate the toxic effect of the ortho-hydroxyl group. Although cells were capable of complete recovery of GJIC after removal of each of the chemicals, only with 2,2'-biphenyldiol and 4,4,'-dichloro-3-biphenylol did the cells demonstrate partial recovery without removal of the chemical. The more noncoplanar conformation of 2,2'-biphenyldiol and 2-biphenylol might explain their more inhibitory behavior in comparison to 3,3'-biphenyldiol and 3-biphenylol, respectively.     

Identification and characterization of ERp29 in rat spermatozoa during epididymal transit

The mammalian epididymis is able to create sequential changes in the composition of luminal fluid throughout its length, wherein spermatozoa undergo morphological, biochemical, and physiological modifications. Subsequently, spermatozoa acquire the ability for fertilization upon reaching the epididymal cauda. In this study, protein variations in Sprague-Dawley rat spermatozoa along the caput and caudal regions of epididymis were investigated by high-resolution two-dimensional gel electrophoresis (2DE) in combination with mass spectrometry. From total protein spots on the 2DE maps, 43 spots were shown to be significantly modified as sperm traverse the epididymis, and seven unambiguous proteins were identified from them. Finally, using indirect immunofluorescence, we demonstrated that localization of one of these seven proteins, the endoplasmic reticulum protein (ERp29) precursor, which was first reported in mammalian spermatozoa, was apparently up-regulated as the sperm underwent epididymal maturation and expressed mainly on caudal sperm. Western blot analysis also revealed that ERp29 precursor, from both whole spermatozoa and membrane proteins, increased significantly as the sperm underwent epididymal maturation. Furthermore, the results from immunofluorescence-stained epididymal frozen sections demonstrated that ERp29 was localized in cytoplasm of epididymal epithelia, and the fluorescence intensity was significantly higher in the caudal epididymis than in the caput. These clues indicated that the ERp29 precursor, perhaps related to secretory protein synthesis and absorbed by spermatozoa, may play a vital role in sperm maturation during the epididymal transit, particularly, in the sperm/organelle membrane.     

Isolation and characterization of natural melanin derived from silky fowl (Gallus gallus domesticus Brisson)

Water-insoluble melanins derived from silky fowl (SF-melanin) were isolated using an enzymatic extraction procedure. The yields of the pigments from periosteum, ovary or testis, trachea, skin and muscle, were 21.3, 13.7, 10.2, 1.1, and 1.0 mg/g, respectively, on a fresh tissue basis. The isolated pigments were identified as melanins according to the Electron Paramagnetic Resonance Spectroscopy spectra. Using synthetic melanin as a calibration, their physicochemical and morphological properties were further characterized by X-ray photoelectron spectroscopy (XPS) and advanced imaging technology. Elemental composition analysis by XPS revealed that the main component of the SF-melanin was eumelanin. The morphological study showed that (1) the SF-melanin displayed ellipsoidal melanosomes which was regarded as representative of the natural material; and (2) the SF-melanin maintained its natural integrity. In conclusion, our enzymatic extraction method yielded highly purified products while maintaining the natural properties of the SF-melanin, which could be chemically, physically, morphologically, defined as eumelanin.     

Structural characterization of a A-type linked trimeric anthocyanin derived pigment occurring in a young Port wine

A new trimeric flavylium derivative pigment was detected for the first time in a young Port wine and structurally characterised using both API-LC ESI MS/MS and NMR techniques. Its structure comprises a malvidin-3-glucoside molecule (terminal unit) linked to two units of flavans (extension units) involving two A-type linkages (C4 → C8 and C7–O–C2 ether linkages). The energies of the minimized geometries for all four conformations of this compound were calculated and comparing the structures of all isomers, it was verified that the binding mode (α or β) between the first and second anthocyanin unit does not have a key role in the compound stability. However, for isomers 1 and 2 where the interaction between the second and third anthocyanin units occurs by a “β” mode in opposition to the “α” mode verified in isomers 3 and 4, revealed a higher stability.     

Isolation and characterization of branched chain fatty acids (other than those derived from phytol) in cod liver oil

A group of mono- and di-unsaturated branched chain fatty acids were isolated and characterized by GC-MS. A GC-MS analysis of the perhydroderivatives of these acids revealed the presence of the following acids: 5 - methyltetradecanoic, 5,7-dimethyltridecanoic, 7-methylhexadecanoic, 5,7- dime t h y 1 te tradecanoic, 7,9-dime t hyl hexadecanoic, 9-met h yloctadecanoic, 7,9- and 9,11-dimethyloctadecanoic acids. Of these, only the 7,9- dimethylhexadecanoic acid was fully characterized in its unhydrogenated form as 7,9-dimethyihexadecadienoate (Δ 63). The presence of the branched methyl groups on alternate odd carbon atoms is uncommon.     

Isolation, characterization of melanin derived from Ophiocordyceps sinensis, an entomogenous fungus endemic to the Tibetan Plateau

Melanins are pigments of high molecular weight formed by oxidative polymerization of phenolic or indolic compounds. In this present study, a black pigment was isolated from the fermentation broth of Ophiocordyceps sinensis, an entomogenous fungus which is endemic to the Tibetan Plateau by alkaline extraction, acid hydrolysis, and repeated precipitation. It was designed as melanin since the physical and chemical properties including its ultraviolet (UV) and infrared (IR) spectra of the black pigment conformed to the characteristic of melanin and similar to the commercial synthetic melanin. The antioxidant activity of melanin derived from O. sinensis was evaluated. They showed much stronger scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and the chelating ability on ferrous ions than that of the water extract from the mycelia of O. sinensis, with IC₅₀ value 18.51 ± 0.85 μg/ml and 2.58 ± 0.26 μg/ml, separately. This is the first report of melanin from O. sinensis and will be helpful for the study on the physiology and the artificial cultivation of this fungus, an endangered species.     

Flour,starch and composite breadmaking quality of various cassava clones

Bread was made using a straight-dough baking process from a local soft wheat flour partially substituted at four levels with flour from nine different cassava (Manihot esculenta, Crantz) clones. The physicochemical properties of the blended flouts, including starch quality, were determined and related to dough rheology, bread volume and crumb characteristics. Breadmaking quality at substitution levels of 100 and 200 g kg^?1 of mixed flour was reliably predicted from the cassava flour diastatic activity only. Flours with relatively high diastatic activities, ie above ～ 145 mg of maltose, had deleterious breadmaking effects. Baking absorption effects were more critical at substitution levels of 300 and 400 g kg^?1. Cassava flour diastatic activity was highly dependent on the moisture contents of the respective tuberous roots, and affected the extent of starch gelatinisation in the breadcrumbs.