Mass spectrometry

Ocimum africanum L. is a distinctive Vietnamese herb, especially common in Tuy Hòa, Phú Yên. This study focuses on extracting and analyzing the chemical composition of the essential oil derived from the leaves of Ocimum africanum. The essential oil was extracted using the steam distillation method and its chemical composition was analyzed using gas chromatography-mass spectrometry (GC-MS).

7p viaburame 14-03-2025 2 0   Download

Red yeast rice is produced from rice using Monascus purpureus fungus, which results in the red colour of the fermented rice. Red yeast rice has been used for a thousand years as a food preservative and in traditional medicine to support vascular and digestive health. This study used Liquid Chromatography-Mass Spectrometry (LC-MS/MS) to concurrently analyse citrinin and monacolin K produced by M. purpureus strain.

11p viaburame 14-03-2025 1 1   Download

In this report, the solid phase extraction technique combined with the gas chromatographymass spectrometry method (GC-MS) was optimized to determine the contamination of nine phthalic acid esters (PAEs) in the surface sediment samples collected from Rao Cai River in Ha Tinh, Vietnam.

7p vifilm 11-10-2024 1 1   Download

Acetylcholinesterase (AChE) has been one of the important and potential targets in the discovery, and development of new drugs for treating and slowing the progression of Alzheimer's disease (AD). This research suggests potential structural frameworks for synthesizing AChE inhibitor derivatives for treating AD.

11p vihyuga 04-03-2025 1 1   Download

Nấm men là tác nhân gây bệnh quan trọng ở người, đặc biệt bệnh do Candida spp. là bệnh phổ biến. Nghiên cứu được tiến hành trên 121 chủng nấm men phân lập được từ 103 bệnh nhân thuộc Bệnh viện Trường Đại học Y Dược Huế và Bệnh viện Trung ương Huế từ 1/2013 - 6/2014. Bài viết trình bày định danh loài một số chủng nấm men phân lập được từ các bệnh nhân được chẩn đoán nhiễm nấm nông hoặc nấm sâu.

6p viharuno 06-01-2025 8 1   Download

Carvedilol is a pharmaceutical substance listed in the “Regulatory requirements of bioequivalence study reports for generic drugs containing APIs upon applying for marketing authorization”. Therefore, a simple method for quantifying carvedilol in human plasma is desirable.

6p vihatake 06-01-2025 3 2   Download

ESI greatly enhanced the ability to characterize protein and peptides by MS.
ESI requires the sample of interest to be in solution- flow in to the ionization source region.
To ionize the sample, high voltage is applied, result in the sample becoming positively or negatively charged; however, positive ionization is used primarily in the analysis proteins and peptides.
As it exits the spray tip, the solution produces submicrometer-sized droplets containing both solute and analyte ions. The sample is then desorbed of solute prior to entering the analyzer region....

76p caubebimu 13-01-2013 51 7   Download

Compare to other documents, our study was for the first time validated the quality criteria of ICP-MS for analyzing nineteen metal levels in wastewater samples. The application of this method was then tested by analyzing nineteen metal levels in twenty-three wastewater samples in the Tham Luong Canal in Ho Chi Minh City. Based on these results, the correlation of the concentration of these metals in wastewater samples was determined.

7p viengels 25-08-2023 10 3   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 19 3   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 20 3   Download

The structure of the O-polysaccharide of the lipopolysaccharide from a diarrheal strain isolated in Bangladesh was studied with sugar, and methylation analysis, NMR spectroscopy, mass spectrometry and partial acid hydrolysis. The strain was first designated as Hafnia alvei, but later found to be a possible new species in the genus Escherichia. Two different polysaccharides were detected, a major and a minor one. The structure of the major polysaccharide is given below, while the structure of the minor one was not investigated. ...

7p system191 01-06-2013 36 6   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 40 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 40 2   Download

The carbohydrate moieties of glycosphingolipids from eggs of the human parasite,Schistosoma mansoni,wereenzy-matically released, labelled with 2-aminopyridine (PA), fractionated and analysed by linkage analysis, partial hydrolysis, enzymatic cleavage, matrix-assisted laser desorption/ionization time-of-¯ight mass spectrometry and nano-electrospray ionization mass spectrometry.

13p research12 23-04-2013 26 2   Download

Lipopolysaccharide (LPS) ofEscherichia colistrain2513 (R4 core-type) yielded after alkaline deacylation one major oligosaccharide by high-performance anion-exchange chro-matography (HPAEC) which had a molecular mass of 2486.59 Da as determined by electrospray ionization mass spectrometry. This was in accordance with the calculated molecular mass of a tetraphosphorylated dodecasaccharide of the composition shown below.

10p tumor12 22-04-2013 40 3   Download

The structure of the lipid A and core region of the lipo-polysaccharide (LPS) fromFrancisella tularensis(ATCC 29684) was analysed using NMR, mass spectrometry and chemical methods. The LPS contains a b-GlcN-(1–6)-GlcN lipid A backbone, but has a number of unusual structural features; it apparently has no substituent at O-1 of the reducing end GlcN residue in the lipid part in the major part of the population, no substituents at O-3 and O-4ofb-GlcN, and no substituent at O-4of the Kdo residue.

7p tumor12 22-04-2013 56 3   Download

Peptides which should be generated from the neuropeptide FF (NPFF) precursor were identified in a neuronal (human neuroblastoma SH-SY5Y) cell line and in COS-7 cells after transient transfection of the human proNPFFAcDNA and were comparedwith those detected in themouse spinal cord. After reverse-phase high performance liquid chromatogra-phy of soluble material, NPFF-related peptides were im-munodetected with antisera raised against NPFF and identified by using on-line capillary liquid chromatography/ nanospray ion trap tandem mass spectrometry. ...

13p tumor12 20-04-2013 34 3   Download

The disulfide structure of the CRIPTO/FRL-1/CRYPTIC (CFC) domain of human Cripto protein was determined by a combination of enzymatic and chemical fragmentation, followed by chromatographic separation of the fragments, and characterization by mass spectrometry and N-terminal sequencing. These studies showed that Cys115 forms a disulfide bond with Cys133, Cys128 with Cys149, and Cys131 with Cys140.

9p tumor12 20-04-2013 28 3   Download

Metabolic fluxes provide a detailed metric of the cellular metabolic phenotype. Fluxes are estimated indirectly from available measurements and various methods have been developed for this purpose. Of particular interest are meth-ods making use of stable isotopic tracers as they enable the estimation of fluxes at a high resolution. In this paper, we present data validating the use of mass spectrometry (MS) for the quantification of complex metabolic flux networks.

18p tumor12 20-04-2013 46 2   Download

Drosophilais a powerful model system to study the regula-tory and effector mechanisms of innate immunity. To iden-tify molecules induced in the course of viral infection in this insect, we have developed a model based on intrathoracic injection of the picorna-like DrosophilaCvirus(DCV).We have used MALDI-TOF mass spectrometry to compare the hemolymph of DCV infected flies and control flies. By contrast with the strong humoral response triggered by injectionof bacteriaor fungal spores, we have identifiedonly one molecule induced in the hemolymph of virus infected flies....

10p tumor12 20-04-2013 30 3   Download