Mass spectra

In this paper, three imidazolium ionic liquids 1-methyl -3-ntetradecylimidazolium chloride ([C14MIM]Cl), 1-n-butyl -3-n-butylimidazolium chloride ([C4BIM]Cl), and 1-n-butyl-3-n-tetradecylimidazolium chloride ([C14BIM]Cl) with different alkyl chain lengths were synthesized and characterized by infrared, 1H-NMR and 13C-NMR NMR and nuclear magnetic resonance, and mass spectra.

6p vikwong 29-09-2024 3 1   Download

Some N-arylidene(4,6-dimethylpyrimidin-2-ylsulfanyl)acetohydrazides have been synthesized. Their structure have been confirmed by UV, IR, 1 H-NMR, 13C-NMR, DEPT 135, DEPT 90 and mass spectra. The relation between the structure and spectral data has been investigated.

5p uocvong04 24-09-2015 31 4   Download

Twenty two N-arylidenehydrazides of [6-(2-hetarylvinyl)-3-oxopyridazine-2-yl] acetic acid have been synthesized starting from levulinic acid. Their structures have been confirmed by UV, IR, NMR and mass spectra. The spectral properties and the biological activity were investigated. Some of the tested compounds exhibit fungicidal and bactericidal activity at 25 µg/ml.

5p uocvong04 24-09-2015 42 2   Download

Some derivatives of formazanes containing furane, thiophene and pyrrole were synthesised by the condensation of hydrazones with aryldiazonium salts at 0 - 5o C. The products were seperated and purified by column chromatography and recrystallisation in ethanol. They are red or violet-red crystals. Their structures were identified by IR-, UV-, 1 H-NMR and mass spectra.

5p uocvong04 24-09-2015 44 2   Download

Three terpenes with Protostane type were isolated from the rhizomes of Alisma plantago- aquatica. The chemical structures of isolated compounds were characterized as 11 ,23S,24R,25- tetrahydroxyprotost-13(17)-en-3-one (alisol A, 1), 11 ,23S,25-trihydroxyprotost-13(17)-en-3- one-24R-yl acetate (alisol A acetate, 2), and 11 ,23S,24S-trihydroxyprotost-13(17),25-dien-3-one (alisol G, 3), by detailed analysis of the 1D- and 2D-NMR spectra such as 1 H-, 13 C-NMR, DEPT 90, DEPT135, HSQC, HMBC, 1 H- 1 H COSY, and by the Electronspray Ionization (ESI) mass spectrum.

6p uocvong04 24-09-2015 64 3   Download

From the fruits of Silybum marianum (L.) Gaertn. cultivated in the North of Vietnam, (±)2,6- bis(4 -hydroxy-3 -methoxy-phenyl)-3,7-dioxabicyclo[3.3.0]octane (pinoresinol) (1) and 3,4 ,5,7- tetrahydroxy-3 -methoxyflavanone (2) were isolated. Their structures were elucidated by analyses of the NMR and mass spectra in comparison with the reported data. This is the first report of both 1 and 2 from Silybum species.

4p uocvong04 24-09-2015 44 4   Download

Derivaties of 1,2,4-triazole and 1,3,4-oxadiazole have a lot of biological activities such as antifungi, antibiotic, antivirus, antitumor, etc. Nineteen hetero-compounds have been synthesized. Their structures have been confirmed by elemental analysis and the spectra methods as UV, IR and NMR. In this study, we focus on the analysis the first defragments on the mass-spectra of some compounds which is derivaties of 1,3,4-oxadiazole and 1,2,4-triazole.

5p uocvong04 24-09-2015 38 3   Download

A new carbohydrate ester of cinnamic acid named gleditschiaside A was isolated from the methanolic extract of the leaves of Gleditschia australis Hemsl., (Caesalpiniaceae). Its structure was elucidated by means of ESI-mass spectrometry, 1 H-NMR, 13 C-NMR (CPD and DEPT), HSQC and HMBC spectra in comparison with the literature.

4p uocvong04 24-09-2015 53 3   Download

Ten aryloxyacetylhydrazones of carvone have been synthesized. Their structures have been confirmed by IR, 1 H-NMR, 13C-NMR, DEPT and mass spectra. The spectral data has been investigated.

6p uocvong02 24-09-2015 47 3   Download

The enzymatic nitration of tryptophan derivatives by oxi-dation of nitrite has been studied using lactoperoxidase and horseradish peroxidase, and compared with the chemical nitration produced by nitrogen dioxide and peroxynitrite. HPLC, mass spectra and NMR analysis of the mixture of products clearly show that nitrationoccurs at position 4-, 6-, 7-, andN 1 of the indole ring, and nitrosation at positionN 1 . Kinetic studies performed on peroxidase/NO2 – /H2O2 sys-tems showed substrate saturation behavior with all the tryptophan derivatives employed. ...

12p dell39 03-04-2013 39 4   Download

Thioredoxin reductase (TrxR) fromEscherichia coli,the mutant proteins E159Y and C138S, and the mutant protein C138Streated with phenylmercuric acetate were reconstituted with [U-13 C17 ,U-15 N4]FAD and analysed, in their oxidized and reduced states, by 13 C-, 15 N- and 31 P-NMR spectroscopy. The enzymes studied showed very similar 31 P-NMR spectra in the oxidized state, con-sisting of two peaks at )9.8 and )11.5 p.p.m. In the reduced state, the two peaks merge into one apparent peak (at)9.8 p.p.m.)....

16p dell39 03-04-2013 43 4   Download