Chromatography

The study clarified the main chemical composition of the roots of F. multiflora. Studying and developing a process of qualitative and quantitative analysis of several active ingredients at the same time. Application of analytical procedure has established and evaluated the content of active ingredients in some F. multiflora medicinal samples. The research results are obtained as a scientific basis for further studies.

23p extraenglish 24-05-2021 26 2   Download

The objects of the thesis: Study and develop the simultaneous analysis method of plant growth stimulants in vegetables using by high-performance liquid chromatography coupled with ion-trapping mass spectrometry. Apply the studied method of analysis and assessment of the current use, residue level and the potential accumulation of plant growth stimulants used in vegetable production in several districts belonged to Hanoi.

28p extraenglish 24-05-2021 12 2   Download

A simple and inexpensive method was developed using liquid - liquid extraction, together with high performance chromatographic method for determination of methoxyfenozide residues in grapes. The evaluated parameters include the extracts by distilled water and acetonitrile solvents. The method was validated using grapes samples spiked with methoxyfenozide at different fortification levels (0.05, 0.1 and 0.5 µg/g). Average recoveries (using each concentration three replicates) ranged 86-95 %, with relative standard deviations less than 5%, calibration solutions concentration in the range 0.

8p chauchaungayxua6 26-06-2020 11 2   Download

In this study, behaviors of gas inside the extraction chromatography column were investigated through experiments and Computation Fluid Dynamics (CFD) simulation. N2 gas once accumulated as bubbles in the packed bed was hardly discharged by the flow of mobile phase.

8p christabelhuynh 31-05-2020 10 2   Download

This method is associated with some attractive characteristics such as good selectivity, very short reaction time, high yield of products, cleaner reaction profile,no harmful by-product, cheap and environmental benign catalyst, simple experimental andwork-up procedure. This procedure does not require solvent separation and purification stepssuch as column chromatography.

10p tocectocec 25-05-2020 14 4   Download

AR-42, a new orally bioavailable, potent, hydroxamate-tethered phenylbutyrate class I/IIB histone deacetylase inhibitor currently is under evaluation in phase 1 and 2 clinical trials and has demonstrated activity in both hematologic and solid tumor malignancies. This report focuses on the preclinical characterization of the pharmacokinetics of AR-42 in mice and rats.

9p caothientrangnguyen 09-05-2020 18 3   Download

Sinh viên giải thích được nguyên lý của phương pháp sắc ký lọc gel và sắc ký trao đổi ion. - Biết cách chuẩn bị gel, làm sắc ký. - Biết cách xây dựng đồ thị nồng độ thành phần protein trong mẫu. i ion (Ion –Exchange Chromatography): chung: - Sắc ký là một họ các kỹ thuật hóa học phân tích dùng để tách các chất trong một hỗn hợp và được tiến hành lần đầu bởi nhà thực vật học người Nga MikhailTsvet (Mikhail Semyonovich Tsvet) vào năm 1903 khi ông đang nghiên cứu về chlorophyll....

25p silverkingq 09-08-2013 447 44   Download

The synthesis of 10 new phosphoenolpyruvate (PEP) analogues with modifications in the phosphate and the carboxylate function is described. Included are two potential irreversible inhibitors of PEP-utilizing enzymes. One incorporates a reactive chloromethylphosphonate function replacing the phosphate group of PEP. The second contains a chloromethyl group substituting for the carboxylate function of PEP. An improved procedure for the preparation of the known (Z)- and (E)-3-chloro-PEP is also given.

11p system191 01-06-2013 35 3   Download

A series of trehalose-based oligosaccharides were isolated from the cytoplasmic fraction of Mycobacterium smegmatis and purified by gel-filtration and paper chromatography and TLC. Their structures were determined by HPLC and GLC to determine sugar composition and ratios, MALDI-TOF MS to measure molecular mass, methylation analysis to determine linkages, 1H-NMR to obtain anomeric configurations of glycosidic linkages, and exoglycosidase digestions followed by TLC to determine sequences and anomeric configurations of the monosaccharides....

8p system191 01-06-2013 36 5   Download

Two novel chondroitinases, chondroitin ABC lyase (EC 4.2.2.4) and chondroitin AC lyase (EC 4.2.2.5), have been purified from Bacteroides stercoris HJ-15, which was isolated from human intestinal bacteria with glycosaminoglycan degrading enzymes. Chondroitin ABC lyase was purified to apparent homogeneity by a combination of QAE-cellulose, CM-Sephadex C-50, hydroxyapatite and Sephacryl S-300 column chromatography with a final specific activity of 45.7 lmolÆmin)1Æmg)1.

7p system191 01-06-2013 50 5   Download

Kininogens are multifunctional proteins found so far mainly in mammals. They carry vasoactive kinins as well as participate in defense, blood coagulation and the acute phase response. In this study, novel kininogens were isolated from Atlantic cod (Gadus morhua L.) and spotted wolffish (Anarhichas minor) by papain-affinity chromatography. The molecular mass of cod kininogen determined by MALDITOF mass spectrometry to be 51.0 kDa and it had pI values of 3.6, 3.9 and 4.4.

8p system191 01-06-2013 38 5   Download

The in vitro activities of purified potato starch branching enzyme (SBE) I and II expressed in Escherichia coli were compared using several assay methods. With the starch– iodine method, it was found that SBE I was more active than SBE II on an amylose substrate, whereas SBE II was more active than SBE I on an amylopectin substrate. Both enzymes were stimulated by the presence of phosphate.

6p system191 01-06-2013 48 4   Download

Department of Biochemistry, University of Rajshahi, Rajshahi-6205. Bangladesh Three lectins were extracted and purified from mulberry seeds by gel filtration of 100% ammonium sulfate saturated crude protein extract followed by ion-exchange chromatography on DEAE and CM-cellulose. The lectins were found to be homogeneous as judged by polyacrylamide disc gel electrophoresis. The molecular masses of the lectins as determined by gel filtration were 175 000 for MSL-1, 120 000 for MSL-2 and 89 500 for MSL-3....

6p system191 01-06-2013 36 5   Download

Glycosphingolipids (GSLs) were purified from adults and plerocercoids of the tapeworm Diphyllobothrium hottai, and their chemical structures were determined. Total lipid fractions prepared from chloroform/methanol extracts of whole tissues were fractionated successively on ion-exchange chromatography, silicic acid column chromatography, and preparative TLC. The purified GSLs were characterized by methylation analysis, TLC-immunostaining, liquid secondary ion MS, MALDI-TOF MS, and 1H-NMR.

11p research12 01-06-2013 39 4   Download

A eukaryotic-type protein serine/threonine kinase, PknA, was cloned from Mycobacterium tuberculosis strain H37Ra. Sequencing of the clone indicated 100% identity with the published pknA sequence of M. tuberculosis strain H37Rv. PknA fused to maltose-binding protein was expressed in Escherichia coli; it exhibited a molecular mass of % 97 kDa. The fusion protein was purified from the soluble fraction by affinity chromatography using amylose resin.

8p research12 01-06-2013 41 3   Download

From the lipopolysaccharide of the deep rough mutant I-69 Rd–/b+ of Haemophilus influenzae two oligosaccharides were obtained after de-O-acylation and separation by high-performance anion exchange chromatography. Their chemical structures were determined by one- and two-dimensional 1H-, 13C- and 31P-NMR spectroscopy as aKdo-4P-(2 fi 6)-bGlcN-4P-(1 fi 6)-aGlcN-1P and aKdo-5P-(2 fi 6)-bGlcN-4P-(1 fi 6)-aGlcN-1P.

6p research12 01-06-2013 31 4   Download

A gene having high sequence homology (45–49%) with the glycerol-1-phosphate dehydrogenase gene from Methanobacterium thermoautotrophicum was cloned from the aerobic hyperthermophilic archaeon Aeropyrum pernix K1 (JCM 9820). This gene expressed in Escherichia coli with the pET vector system consists of 1113 nucleotides with an ATG initiation codon and a TAG termination codon. The molecular mass of the purified enzyme was estimated to be 38 kDa by SDS/PAGE and 72.4 kDa by gel column chromatography, indicating presence as a dimer....

8p research12 01-06-2013 27 4   Download

Immunoblotting analyses revealed the presence of carb-oxylesterase in theporcine small intestine, liver, submaxillary andparotidglands, kidney cortex, lungs and cerebral cortex. In the intestinal mucosa, the pI 5.1 enzyme was detected in several subcellular fractions including the microvillar frac-tion. Both fatty monoacylated and diacylated monomeric (F1), trimeric (F3) and tetrameric (F4) forms of the intestinal protein were puri®ed here for the ®rst time by performing hydrophobic chromatography and gel ®ltration....

9p research12 01-06-2013 41 6   Download

The diseaseFusarium head blight (scab) causes severe problems for farmers and for the industries that use cereals. It is likely that the fungi that cause scab (Fusariumspp.) use various enzymes when they invade grains. We are studying enzymes that the fungi may use to hydrolyze grain proteins. To do this,Fusarium culmorumwas grown in a gluten-con-taining medium from which an alkaline serine proteinase with a molecular mass of 28.7 kDa was puri®ed by size-exclusion and cation exchange chromatographies....

10p research12 01-06-2013 54 5   Download

The osmoregulated periplasmic glucans (OPGs) produced byRhodobacter sphaeroides, a free-living organism, were isolated by trichloracetic acid treatment and gel permeation chromatography. Compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance.R. sphaeroidespredominantly synthesizes acyclic glucan containing 18 glucose residues that canbe substituted by one to seven succinyl esters residues at the C6position of some of the glucose residues, and by one or two acetyl resi-dues....

9p research12 29-04-2013 36 1   Download