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Soluble catechol-O-methyltransferase (S-COMT) is an important target protein due to its involvement in some human disorders. The main scope of the work was to develop an approach to purify and identify S-COMT. Its isoelectric point was 5.0 determined with Offgel. A simplified process including extraction, selective precipitation, ammonium sulfate precipitation, gel filtration chromatography and anion...
A high-performance liquid chromatography with electrochemical detection (HPLC-ECD) method was developed to determine the activity of S-catechol-O-methyltransferase (COMT) in rat tissues including the liver, kidney, lung ,spleen and brain. The 3,4-dihydroxybenzoic acid was used as the substrate for S-COMT in rat tissues. After incubated with different tissues, the product 4-hydroxy-3-methoxybenzoic...
It's well known that irreversible cross-linked complexes between proteins, produced by formaldehyde interacting with free amino or amide groups to form Schiff s base, are formed in diabetes and aging patients. To identify such specific modified peptides as biomarkers for clinical diagnose of diabetes and AD, cross-linkage of formaldehyde with human serum albumin (HSA) was analyzed by LC/ESI/MS in...
A novel natural macromolecule Antibacterial material was synthesized by reaction with carboxymethyl-chitosan, decanoyldimethylammonium and epichlorohydrin. Long chain quaternary ammonium (OGTA) was prepared by reaction with decanoyldimethylammonium and epichlorohydrin, using isopropylalcohol as solvent, at 55degC for 6 hours, and vacuum distillation. The yield was 87 percent. With 0.5 g CMCTS and...
Creatine is alleged to be a popular nutrition to enhance sports performance. It can be metabolized to methylamine, which is further converted to formaldehyde, hydrogen peroxide and ammonium by semicarbazied-sensitive amine oxidases (SSAO). Until now, there is no scientific available data for demonstration the long-term health risks of chronic creatine ingestion. In this study, we demonstrated that...
AGEs are a heterogeneous group of proteins that have been shown to react with the amino group of the N-terminal amino acid residue and the side-chains of arginine and lysine residues. Glycation induced protein modifications has been implicated in diabetes and its associated complications like nephropathy, retinopathy, aging as well as in atherosclerosis, Alzheimer's and Parkinson's diseases. The identification...
The enantiomers of three chiral compounds of neural interest, N-(2-heptyl)propargylamine (2-HPA), 2-heptylamine (2-HA) and 2-HPPA were separated analytically using capillary electrophoresis (CE) with cyclodextrin chiral selectors. And dansyl chloride was chosen as the reagent for pre-column derivation to give 2-HPA derivatives. The effects of pH, beta-CD concentration, electrolyte concentration and...
The neural stem cells were induced by low-level dopamine (DA). We allowed cells 72 h of differentiation before protein extraction. The global proteins of neural stem cells and dopaminergic neurons were extracted. In this study, the protein from cell lysat was rudiment separated by SDS-PAGE, and the gel strip was cut into several portions. The protein in each portion is digested by trypsin, and then...
This paper described a novel method to immobilize trypsin on IAM. The immobilization procedures involved the following steps: IAM was packed into the fused silica capillary (400 mum I.D.times690 mum O.D.times5 cm length); subsequently, trypsin was dynamically immobilized on IAM by injecting 1 mg/ml trypsin aqueous solution using the frontal chromatography. The activity of trypsin-micro-IMERs was on-line...
In this study, Cephalotaxus sinensis (Rehd et Wile) Li (Cephalotaxaeeae), plant was examined for phenolic constituents and antioxidant capacity, to determine their potential as a source of naturat antioxidants. Total polyphenol content (TPC) were determined spectrophotometrically, after extraction of ptant material with assorted solvents at 80degC for 3 hour. Antioxidant activity of aqueous extracts...
HPLC was used to separate chiral compounds with chiral column. Another method was used in HPLC with chiral mobile phase additives to separate chiral compounds. Using chiral mobile phase additives is a good way to separate the chiral compounds. The structure of the derivative takes an important role in separation. We derivatized 2-heptamine with benzene sulfonyl chloride and dansyl chloride, Using...
Monoamine oxidase (MAO) immobilized in the immobilized artificial membrane (IAM) was packed into a capillary to make a chromatography column to simulate the MAO function of catalyzing the oxidative deamination of amine in organism. MAO marked with quantum dots (QDs) was used as probe to demonstrated that MAO was immobilized in the IAM hydrophobic interface, and the enzymatic activity analysis proved...
Capillary electrophoresis (CE) was an advanced method for protein separation. Under extreme acidic condition (pH <3), fused silica capillary inner wall was protonated, so that the electrostatic adsorption between protein and inner wall of capillary could be suppressed effectively, which caused the resolution and column efficiency were improved. In this paper, four model proteins were separated...
A UV method was established to determination the total flavonoids in extractive solution from Torreya grandis Fort, leaves, and a RP-HPLC method was developed and validated to quantify 4', 5, 7-Trihydroxyflavone- 5- O- [alpha- L- Rhamno-pyranosyl- (1rarr4)- 6- O- acetyl- beta- D- glucopyranoside] (FRG). The dried leaf samples were extracted using methanol. The extracts were directly analyzed, without...
A method for the rapid determination of monoamine oxidase (MAO) activity by capillary electrophoresis (CE) has been established. The effect factors including the pH, the concentration of electroosmotic flow modifier (OFM), the salt concentration of running buffer were investigated in detail. The analysis was performed in an uncoated fused-silica capillary with 50 mum id and total length of 70 cm (40...
Cephalotaxus sinensis (Rehd et Wile) Li, belongs to family Cephalotaxaceae, common in China, is an indigenous medicinal plant due to its antiascariasis, antiinflammation, anticough and antidyspepsia activity. The overindulgence of free radicals has been concerned in the development of chronic diseases and play an imperative role in the development of neurodegenerative disorders, such as Alzheimer's...
Phytochemical investigation of Thesium chinense Turcz, led to the isolation of seven compounds from the ethyl acetate extract using column chromatography and preparative TLC. The structures of these compounds were identified as, kaempferol-3-O-beta-D-glucopyranosyl (1rarr2)-O-beta-D-6- acetlyglucopyranoside (I), kaempferol-5-methylether (II), apigenin-5-O- [-L-Rhamnopyranosyl- (1rarr4)-beta-D-glucopyranoside]...
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