In order to prepare antioxidant peptide through hydrolyzing low-value protein resources with bacterial extracellular proteases and to discover novel proteases, crude extracellular protease from Pseudoalteromonas sp. SHK1-2 was obtained through fermentation which was used to hydrolyze collagen extracted from Cirrhinus molitorella skin. Small peptide fraction was isolated from hydrolysate by ultrafiltration and Sephadex LH-20 size exclusion chromatography and showed 1, 1-diphenyl-2-picrylhydrazyl radical scavenging activity (35.6%±7%), oxygen radical absorbance capacity and inhibition of DNA oxidation damage. The molecule weight was 776.2 Da, and amino acid sequence was Thr-Ala-Gly-His-Pro- Gly-Thr-His through liquid chromatography mass spectrum. Our findings suggest that peptide obtained from low-value protein of fish waste by hydrolysis with bacterial protease has antioxidant activity.
Amino Acid Sequence ; Animals ; Antioxidants ; chemistry ; Chromatography, Gel ; Collagen ; chemistry ; Cyprinidae ; Dextrans ; Hydrolysis ; Oxidation-Reduction ; Peptide Hydrolases ; Peptides ; chemistry ; Skin ; chemistry

Dextranase can degrade dextran polymer into low molecular weight polysaccharide. Dextranase and its hydrolysates are widely used in food, medicine and chemical industries. Studies on dextranase progresses rapidly in recent years. We reviewed literature reports combined with our study about the progress of dextranase and its potential applications in industry. In addition, we addressed hot topics and emphasized on the current research about dextranase, existing problems in domesticstudies and the future research needs needs.
Dextranase ; chemistry ; Dextrans ; chemistry ; Molecular Weight ; Polymers

The aimed of this study was to prepare stabilized thiomers to overcome the poor stability character of traditional thiomers. Poly(acrylic acid)-cysteine (PAA-Cys) was synthesized by conjugating cysteine with poly(acrylic acid) and poly(acrylic acid)-cysteine-6-mercaptonicotinic acid (PAA-Cys-6MNA, stabilized thiomers) was synthesized by grafting a protecting group 6-mercaptonicotinic acid (6MNA) with PAA-Cys. The free thiol of PAA-Cys was determined by Ellmann's reagent method and the ratio of 6MNA coupled was determined by glutathione reduction method. The study of permeation enhancement and stabilized function was conducted by using Franz diffusion cell method, with fluorescein isothiocyanate dextran (FD4) used as model drug. The influence of polymers on tight junctions of Caco-2 cell monolayer was detected with laser scanning confocal fluorescence microscope. The results indicated that both PAA-Cys and PAA-Cys-6MNA could promote the permeation of FD4 across excised rat intestine, and the permeation function of PAA-Cys-6MNA was not influence by the pH of the storage environment and the oxidation of air after the protecting group 6MNA was grafted. The distribution of tight junction protein of Caco-2 cell monolayer F-actin was influenced after incubation with PAA-Cys and PAA-Cys-6MNA. In conclusion, stabilized thiomers (PAA-Cys-6MNA) maintained the permeation function compared with the traditional thiomers (PAA-Cys) and its stability was improved. The mechanism of the permeation enhancement function of the polymers might be related to their influence on tight junction relating proteins of cells.
Acrylic Resins ; chemistry ; Actins ; metabolism ; Animals ; Caco-2 Cells ; Cysteine ; chemistry ; Dextrans ; Fluorescein-5-isothiocyanate ; analogs & derivatives ; Glutathione ; Humans ; Intestinal Absorption ; Intestinal Mucosa ; drug effects ; Nicotinic Acids ; chemistry ; Rats ; Sulfhydryl Compounds ; chemistry

Fourteen compounds were isolated from Dalbergia odoriferae and purified by repeated column chromatography on silica and sephadex LH-20 gel and structurally identified by spectral analysis. These compounds were identified as 4, 9-dimethoxy-3-hydroxypterocarpan (1), medicarpin (2), 2', 4', 5-trihydroxy-7-methoxyisoflavone (3), 2', 3', 7-trihydroxy-4'-methoxyisoflavan (4), formononetin (5), 3, 8-dihydroxy-9-methoxypterocarpan (6), koparin (7), 3-hydroxy-9-methoxypterocarp-6a-ene (8), 2'-hydroxyformononetin (9), stevenin (10), 2', 7-dihydroxy-4', 5'-dimethoxyisoflavone (11), lyoniresinol (12), 2, 4-dihydroxy-5-methoxy-benzophenone (13) and neokhriol A (14). Compounds 1, 3, 4, 6, 8, 12 and 14 were isolated from this plant for the first time. Antibacterial activity assay showed that compound 4 had inhibitory effect on Ralstonia solanacearum.
Anisoles ; chemistry ; isolation & purification ; pharmacology ; Anti-Bacterial Agents ; chemistry ; isolation & purification ; pharmacology ; Benzophenones ; chemistry ; isolation & purification ; pharmacology ; Chromatography ; methods ; Dalbergia ; chemistry ; Dextrans ; Gels ; Isoflavones ; chemistry ; isolation & purification ; pharmacology ; Microbial Sensitivity Tests ; Naphthalenes ; chemistry ; isolation & purification ; pharmacology ; Plant Extracts ; chemistry ; isolation & purification ; pharmacology ; Pterocarpans ; chemistry ; isolation & purification ; pharmacology ; Ralstonia solanacearum ; drug effects ; growth & development ; Silica Gel

This study aimed to characterize and magnetic resonance imaging (MRI) track the mesenchymal stem cells labeled with polylysine-coated superparamagnetic iron oxide (PLL-SPIO). Rat bone marrow derived mesenchymal stem cells (rMSCs) were labeled with 25, 50 and 100 microg/mL PLL-SPIO for 24 hours. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity and differentiation potential. Electron microscopic observations and Prussian blue staining revealed that 75% -100% of cells were labeled with iron particles. PLL-SPIO did not show any cytotoxicity up to 100 microg/mL concentration. Both 25 microg/mL and 50 microg/mL PLL-SPIO labeled stem cells did not exhibit any significant alterations in the adipo/osteo/chondrogenic differentiation potential compared to unlabeled control cells. The lower concentration of 25 microg/mL iron labeled cells emitted an obvious dark signal in T1W, T2WI and T2 * WI MR image. The novel PLL-SPIO enables to label and track rMSCs for in vitro MRI without cellular alteration. Therefore PLL-SPIO may potentially become a better MR contrast agent especially in tracking the transplanted stem cells and other cells without compromising cell functional quality.
Animals ; Bone Marrow Cells ; Cell Differentiation ; Dextrans ; chemistry ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; chemistry ; Mesenchymal Stromal Cells ; cytology ; Polylysine ; chemistry ; Rats ; Staining and Labeling

The chemical constituents of 95% ethanol extract of Melastoma dodecandrum were isolated and purified by chromatography on silica gel, Sephadex LH-20, and HPLC, to obtain thirteen compounds eventually. On the basis of their physico-chemical properties and spectroscopic data, these compounds were identified as quercetin (1), quercetin-3-O-β-D-glucopyranoside (2), quercetin-3-O-(6"-O-p-coumaroyl) -β-D-glucopyranoside (3), kaempferol (4), kaempferol-3-O-β-D-glucopyranoside (5), kaempferol-3-O- [2",6"-di-O-(E)-coumaroyl]-β-D-glucopyra-noside (6), luteolin (7), luteolin-7-O-(6"-p-coumaroyl) -β-D-glucopyranoside (8), apigenin (9), apigenin-7-(6"-acetyl-glucopyranoside) (10) , naringenin (11), isovitexin (12), and epicatechin-[8,7-e] -4β-(4-hydroxyphenyl)-3,4-dyhydroxyl-2(3H)-pyranone (13). Eight compounds(3,5,6,8-11 and 13) were obtained from M. dodecandrum for the first time.
Apigenin ; analysis ; Chromatography ; methods ; Chromatography, High Pressure Liquid ; Dextrans ; Flavanones ; analysis ; Flavonoids ; analysis ; chemistry ; Glycosides ; analysis ; chemistry ; Kaempferols ; analysis ; Luteolin ; analysis ; Magnoliopsida ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; analysis ; Silica Gel

OBJECTIVETo study the chemical constituents of Rhododendron seniavinii.

METHODCompounds were isolated from the aqueous extract of the leaves of R. seniavinii by using Sephadex LH-20, ODS open column chromatography and other means. Their structures were elucidated according to spectral data and physiochemical properties.

RESULTThirteen compounds were isolated from R. seniavinii and identified as 5-methoxydehydroconiferyl alcohol (1), dehydroconiferyl alcohol (2), (-)-syringaresinol (3), (-)-lyoniresinol (4), (+)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (5), (-)-lyoniresinol 3alpha-O-beta-D-glucopyranoside (6), 3,4,5-trimethoxyphenyl-1-O-beta-D-glucopyranoside (7), nikoenoside (8), 3,5,7-trihydroxychromone-3-0-alpha-L-rhamnopyranoside (9), 3,4,5-trimethoxyphenol (10), scopoletin (11), scopolin (12) and quercitrin (13).

CONCLUSIONCompounds 1-12 were obtained from this plant for the first time.

Chromatography, Gel ; Coumarins ; chemistry ; isolation & purification ; Dextrans ; Glucosides ; chemistry ; isolation & purification ; Mass Spectrometry ; Plant Extracts ; chemistry ; isolation & purification ; Plant Leaves ; chemistry ; Plants, Medicinal ; chemistry ; Quercetin ; analogs & derivatives ; chemistry ; isolation & purification ; Rhododendron ; chemistry ; Scopoletin ; chemistry ; isolation & purification

OBJECTIVETo determine the chemical constituents of Gentiana rhodantha.

METHODTo isolate the constituents, column chromatography over silica gel, MCI, Sephadex LH-20 and C18 reverse-phased silica gel were used. Spectroscopic methods were used to elucidate the structures of the isolated compounds.

RESULTSixteen compounds were isolated and elucidated as ten phonemic compounds, namely 1,3,7,8-tetrahydroxylxanthone (1), rhodanthenone D (2), 1,3,6,7-tetrahydroxylxanthone (3), 1,3,7-trihydroxy-4,8-dimethoxyxanthone (4), quercetin (5), isoorientin (6), mangiferin (7), norswertianolin (8), gallic acid ethyl ester (9) and salicylic acid (10), and six triterpenes including alpha-amyrin (11), erythrodiol 3-O-palmitate (12), ursolic aldehyde (13), uvaol 3-O-acetyl (14), ursolic acid (15) and 2alpha-hydroxyursolic acid (16).

CONCLUSIONCompounds 4-6, 8, 10-12, 15 and 16 were isolated from this plant for the first time. Compounds 1 and 3 were obtained firstly from the genus Gentiana and compounds 9, 13-14 were firstly from the family Gentianaceae.

Chromatography, Gel ; Chromatography, Reverse-Phase ; Dextrans ; Gentianaceae ; chemistry ; Mass Spectrometry ; Oleanolic Acid ; analogs & derivatives ; chemistry ; isolation & purification ; Plant Extracts ; chemistry ; isolation & purification ; Plants, Medicinal ; chemistry ; Quercetin ; chemistry ; isolation & purification ; Salicylic Acid ; chemistry ; isolation & purification ; Silica Gel ; Triterpenes ; chemistry ; isolation & purification ; Xanthones ; chemistry ; isolation & purification

To evaluate the effect of chlorogenic acid (CGA), a polyphenol abundant in coffee, on retinal vascular leakage in the rat model of diabetic retinopathy, Sprague-Dawley rats were divided into four groups: controls, streptozotocin-induced diabetic rats, and diabetic rats treated with 10 and 20 mg/kg chlorogenic acid intraperitoneally daily for 14 days, respectively. Blood-retinal barrier (BRB) breakdown was evaluated using FITC-dextran. Vascular endothelial growth factor (VEGF) distribution and expression level was evaluated with immunohistochemistry and Western blot analysis. Expression of tight junction proteins, occludin and claudin-5, and zonula occludens protein, ZO-1 was also evaluated with immunohistochemistry and Western blot analysis. BRB breakdown and increased vascular leakage was found in diabetic rats, with increased VEGF expression and down-regulation of occludin, claudin-5, and ZO-1. CGA treatment effectively preserved the expression of occludin, and decreased VEGF levels, leading to less BRB breakdown and less vascular leakage. CGA may have a preventive role in BRB breakdown in diabetic retinopathy by preserving tight junction protein levels and low VEGF levels.
Animals ; Blood-Retinal Barrier/*drug effects ; Chlorogenic Acid/metabolism/*pharmacology ; Claudin-5/metabolism ; Dextrans/chemistry ; Diabetes Mellitus, Experimental/complications/metabolism/*pathology ; Diabetic Retinopathy/etiology/prevention & control ; Down-Regulation ; Fluorescein-5-isothiocyanate/chemistry ; Male ; Occludin/metabolism ; Rats ; Rats, Sprague-Dawley ; Retina/*metabolism ; Tight Junction Proteins/metabolism ; Vascular Endothelial Growth Factor A/metabolism ; Zonula Occludens-1 Protein/metabolism

OBJECTIVETo construct angiogenesis-specific RGD10-NGR9 dual-targeting superparamagnetic iron oxide nanoparticles, and to evaluate its magnetic resonamce imaging (MRI) features in nude mice and potential diagnostic value in tumor MRI.

METHODSDual-targeting peptides RGD10-NGR9 were designed and synthesized. Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were synthesized by chemical co-precipitation method and the surface was modified to be hydrophilic by coating with dextran. The dual-targeting peptides RGD10-NGR9 were conjugated to USPIO. Cell binding affinity and up-taking ability of the dual-targeting USPIO nanoparticles to integrin ανβ3-APN positive cells were subsequently tested by Prussian blue staining and phenanthroline colorimetry in vitro. The RGD10-NGR9 conjugated with USPIO was injected intravenously into xenograft mice, which were scanned by MRI at predetermined time points. The MRI and contrast-to-noise ratio (CNR) values were calculated to evaluate the ability of dual-targeting USPIO as a potential contrast agent in nude mice.

RESULTSP-CLN-Dextran-USPIO nanoparticles with stable physical properties were successfully constructed. The average diameter of Fe3O4 nanoparticles was 8-10 nm, that of Dextran-USPIO was about 20 nm and P-CLN-Dextran-USPIO had an average diameter about 30 nm. The in vitro studies showed a better specificity of dual-targeting USPIO nanoparticles on proliferating human umbilical vein endothelia cells (HUVEC). In vivo, RGD10-NGR9-USPIO showed a significantly reduced contrast in signal intensity and 2.83-times increased the CNR in the tumor MRI in xenograft mice.

CONCLUSIONThis novel synthesized RGD10-NGR9 dual-targeting USPIO is with better specific affinity in vitro and in vivo, and might be used as a molecular contrast agent for tumor angiogenesis MRI.

Adenocarcinoma ; diagnosis ; metabolism ; pathology ; Aminopeptidases ; analysis ; Animals ; Cell Line, Tumor ; Cells, Cultured ; Contrast Media ; chemistry ; Dextrans ; chemistry ; Ferrosoferric Oxide ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; Humans ; Integrin alphaVbeta3 ; analysis ; Lung Neoplasms ; diagnosis ; metabolism ; pathology ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; chemistry ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Oligopeptides ; chemistry ; Particle Size ; Signal-To-Noise Ratio