MS spectroscopies

Trong báo cáo này, phương pháp phân tích Sắc ký khí ghép nối khối phổ (Gas Chromatography coupled Mass Spectroscopy - GC/MS) được sử dụng nhằm phân tích thành phần dạng khí sinh ra từ quá trình đốt cháy vải sợi cotton chưa qua xử lý, cũng như vải sợi cotton chống cháy xử lý bằng hệ phụ gia Pyrovatex CP, để từ đó thu được cái nhìn rõ nét hơn về tính an toàn của loại vật liệu này trong điều kiện sử dụng thực tế.

7p vimichaelfaraday 28-12-2023 9 5   Download

Three fungal metabolites, (1) O-methylsilvaticol, (2) orthosporin and (3) diplosporin were isolated from a rare fungus, Kretzschmaria sandvicensis, collected in Dien Bien, in northwest Vietnam. Their structures were established using a combination of high resolution MS (FT-ICR-MS) and 1H-NMR, 13C-NMR, HSQC and HMBC spectroscopy. They were evaluated for anticancer properties against the KB cell line.

5p tamynhan8 04-11-2020 12 2   Download

The corrosion inhibition efficiencies of two novel Schiff bases, namely (E)-3-[thiophen-2-lmethyleneamino]benzoic acid (T2YMABA) and (E)-4-(5-[(2-phenylhydrazono) methyl]thiophen-2-yl)benzoic acid (PHMT2YBA) on mild steel (MS) in 1.0M HCl solution has been investigated and compared using electrochemical impedance spectroscopy and potentiodynamic polarization analysis.

10p tocectocec 25-05-2020 19 2   Download

Some hydrazones from hydrazides of substituted benzoic acids with o- hidroxyacetophenones have been prepared by the condensation of hydrazides of substituted benzoic acids with o - hidroxyacetophenones. The structure of these products have been determined by IR, 1H-NMR and MS spectroscopies.

7p uocvong04 24-09-2015 46 3   Download

4-Amino-3-(2-methoxy-4-propylphenoxymethylen)-(1H)-1,2,4-triazole-5-thione was prepared from eugenol in Ocimum Sanetum L. essential oil. A series of 7 imines were synthesized from these key compounds by condensing it with different aromatic aldehydes. The structures of these imines were confirmed by EI MS, IR and NMR spectroscopy, in many cases 2D NMR spectra are also used.

5p uocvong04 24-09-2015 30 3   Download

Two coumarins micromelin and magnolioside and three flavonoides have been isolated from the leaves of Micromelum hirsutum. Their structures have been determined on the basis of MS, 1 H and 13 C NMR spectroscopy.

5p uocvong04 24-09-2015 36 4   Download

Kỹ thuật khối phổ hai lần MS/MS hay còn gọi là Tandem MS sử dụng phân mảnh bằng bắt giữ điện tử (Electron Capture Dessociation-ECD) đo trên thiết bị phổ khối cộng hưởng ion cyclotron có biến đổi Fourier (Fourier Transformation Ion Cyclotron Resonance Mass Spectroscopy -FT-ICR-MS) được ứng dụng như một giải pháp hữu hiệu trong nghiên cứu các phân tử sinh học có kích thước lớn và cấu trúc phức tạp như peptit và protein.

4p uocvong04 24-09-2015 60 3   Download

Some hydrazones from hydrazides of substituted benzoic acids with o-hydroxyacetophenone have been prepared by the condensation of o-hydroxyacetophenone with hydrazides of substituted benzoic acids. The structure of these products have been determined by IR, 1 H-NMR and MS spectroscopies.

4p uocvong04 24-09-2015 41 2   Download

3-methyl-1-buten-3-yl-6-o-
-xylopyranosyl-
-D-glucopyranoside has been isolated from the methanolic extract of the roots of Vietnamese Paederia scanders. Its structure was elucidated by the combination of 2D NMR, IR and high resolution FAB-MS spectroscopy and chemical reaction, such as acetylation.

4p uocvong04 24-09-2015 40 4   Download

A new sesquiterpen glycoside-cinnamic acid ester named fissispallin besides afzeline has been isolated from the leaves of Fisisstigma pallens (Fin.&Gagn.) Merr. Their structures were elucidated on the basis of MS, 1 H- and 13C-NMR spectroscopies.

6p uocvong03 24-09-2015 61 3   Download

The structure of the lipopolysaccharide (LPS) of Pseudomonas aeruginosa immunotype 1 was studied after mild acid and strong alkaline degradations by MS and NMR spectroscopy. Three types of LPS molecules were found, including those with an unsubstituted glycoform 1 core (A) or an isomeric glycoform 2 core substituted with one O-polysaccharide repeating unit (B) or with a long-chain O-polysaccharide. Therefore, of two core glycoforms, only glycoform 2 accepts the O-polysaccharide. LPS molecules, an O-acetyl group is present in the outer core region at unknown position....

10p research12 01-06-2013 36 4   Download

A sialylated lacto-N-neotetraose (Sial-lNnT) structural unit was identified and structurally characterized in the lipo-polysaccharide (LPS) from the genome-sequenced strain Road (RM118) of the human pathogenHaemophilus influ-enzaegrown in the presence of sialic acid. A combination of molecular genetics, MS and NMR spectroscopy techniques showed that this structural unit extended from the proximal heptose residue of the inner core regionof theLPSmolecule.

11p research12 23-04-2013 36 2   Download

Structural elucidation of the lipopolysaccharide (LPS) from threeserotypef Haemophilus influenzaeclinical isolates RM6255, RM7290and RM6252 has been achieved using NMR spectroscopy techniques and ESI-MS on O-deacyl-ated LPS and core oligosaccharide material (OS) as well as ESI-MS n on permethylated dephosphorylated OS. This is the first study to report structural details on LPS from sero-type f strains.

15p tumor12 20-04-2013 41 2   Download

The structures of the oligosaccharides obtained after acetic acid hydrolysis and alkaline deacylation of the rough-type lipopolysaccharide (LPS) from Pectinatus frisingensisstrain VTTE-82164 were analysed usingNMR spectroscopy, MS and chemical methods. The LPS contains two major struc-tural variants, differing by a decasaccharide fragment, and some minor variants lacking the terminal glucose residue.

11p fptmusic 16-04-2013 45 2   Download

The core structure of the lipopolysaccharide (LPS) isolated from a rough strain of the phytopathogenic bacterium Pseudomonas syringaepv.phaseolicola, GSPB 711, was investigated by sugar and methylation analyses, Fourier transform ion-cyclotron resonance ESI MS, and one- and two-dimensional 1 H-, 13 C- and 31 P-NMR spectroscopy. Strong alkaline deacylation of the LPS resulted in two core-lipid A backbone undecasaccharide pentakisphos-phates in the ratio
2.

0p awards 05-04-2013 38 2   Download

The chemical structure of a novel lipid A, the major com-ponent of the lipopolysaccharide from the marine gamma-proteobacteriumMarinomonas vagaATCC 27119 T ,was determined by compositional analysis, NMR spectroscopy, and MS.

10p dell39 03-04-2013 49 4   Download

We have isolated a nonfucosylated and three variously fucosylated neutral oligosaccharides from human milk that are based on theiso-lacto-N-octaose core. Their structures were characterized by the combined use of electrospray mass spectrometry (ES-MS) and NMR spectroscopy. The branching pattern and blood group-related Lewis deter-minants, together with partial sequences and linkages of these oligosaccharides, were initially elucidated by high-sensitivity ES-MS/MS analysis, and then their full structure assignment was completed by methylation analysis and 1 H-NMR.

15p dell39 03-04-2013 60 3   Download

The intracellular accumulation of low molecular mass organic compounds in response to stressful conditions was investigated in the thermophilic bacterium Petrotoga miotherma, a member of the order Thermotogales. This led to the discovery of a new solute, whose structure was established as a-d-mannopyranosyl-(1fi2)-a-d-glucopyranosyl-(1 fi2)-glycerate (MGG) by MMR spectroscopy and MS.

8p galaxyss3 19-03-2013 24 4   Download

Synthetic hyaluronan oligosaccharides with defined structures and their pyridylaminated derivatives were used to investigate the mechanism of hydrolysis of hyaluronan by bovine testicular hyaluronidase. The products of the hydrolysis were analyzed by HPLC and ion-spray mass spectroscopy (MS).

11p mobifone23 18-01-2013 58 3   Download

 UV-Visible spectra can be interpreted to help determine molecular structure, but this is presently confined to the analysis of electron behavior in known compounds.  Information from other techniques (NMR, MS, IR) is usually far more useful for structural analysis  However, UV-Vis evidence should not be ignored!

18p qdung92ct 03-07-2012 58 4   Download