A sensitive 1 H NMR spectroscopic method for the quantification of capsaicin and capsaicinoid: morpho‐chemical characterisation of chili land races from northeast India

2020 ◽  
Vol 32 (1) ◽  
pp. 91-103
Author(s):  
Pranjit Kumar Bora ◽  
Phirose Kemprai ◽  
Rubi Barman ◽  
Debabrata Das ◽  
Aamir Nazir ◽  
...  

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.



2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600
Author(s):  
Jasmeen Sidana ◽  
William J. Foley ◽  
Inder Pal Singh

A simple, rapid, accurate and selective 1H NMR spectroscopic method to detect and quantify euglobals in the leaves of Eucalyptus loxophleba ssp. lissophloia has been developed. The method allows for the estimation of total concentration of diformylphloroglucinol-monoterpene adducts, as well as the quantitation of sabinene- and α/β-phellandrene-adducts, separately. The method was validated for accuracy, precision and linearity using as reference standards 2-ethyl phenol and mixtures of jensenone, a monomeric formylated phloroglucinol, and 2-ethyl phenol.



2019 ◽  
Vol 31 (1) ◽  
pp. 28-36 ◽  
Author(s):  
Bhaskar Protim Mahanta ◽  
Dristi Sut ◽  
Phirose Kemprai ◽  
Manabi Paw ◽  
Mohan Lal ◽  
...  


2012 ◽  
Vol 9 (2) ◽  
pp. 593-597
Author(s):  
Satyendra N. Shukla ◽  
Pratiksha Gaur ◽  
Ripul Mehrotra ◽  
Radhey S. Srivastava

A bimetallic cuprous complex was accidentally reported, during synthesis of a dinucleating spacer incorporating two 2-chloropyridine units through Sandmayer reaction. The product was characterized by elemental analysis, FAB-Mass, FT-IR, UV, magnetic susceptibility and1H-NMR spectroscopic method. A possible mechanism is also proposed.



2019 ◽  
Vol 14 (9) ◽  
pp. 1934578X1987893
Author(s):  
Yasunori Yaoita ◽  
Koichi Machida

Conformational analysis suggests that thujopsene (1) can exist as 2 possible conformations, steroidal and nonsteroidal. The conformation of 1 has been investigated using a NMR spectroscopic method. Analyses of the 1H NMR, ROESY, and long-range 1H-1H COSY spectra indicate that 1 exists in a steroidal conformation. Although the conformations of related compounds 2 and 3 were originally assigned as nonsteroidal, careful reexamination of the published NMR data indicates that both compounds exist in a steroidal conformation.



2008 ◽  
Vol 14 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Sandra Konstantinovic ◽  
Agnes Kapor ◽  
Blaga Radovanovic ◽  
Andrea Deak

Isatin-3-phenylhydrazone was synthesized and X-ray crystal structure of this compound has been solved. Its structure was also established using FTIR, UV/Vis and H-NMR spectroscopic method. The compound was tested for antimicrobial activity against Staphylococcus aureus, Bacillus subtilus, Enterococcus D, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa and Candida albicans. Stability of isatin-3-phenylhydrazone toward UV-A irradiation has been studied in this work. Isatin derivative undergoes bleaching following first-order kinetics.



Praxis ◽  
2009 ◽  
Vol 98 (3) ◽  
pp. 143-149 ◽  
Author(s):  
Knechtle ◽  
Wirth ◽  
Knechtle ◽  
Kohler
Keyword(s):  

Ein 81-jähriger Läufer mit Status nach aortokoronarem Bypass bei bekannter koronarer Herzkrankheit hat einen 100-km-Lauf in 19 h und 45 min erfolgreich beendet. Vor und unmittelbar nach dem Lauf wurden Fett- und Muskelmasse nicht-invasiv sowohl mit der bioelektrischen Impedanzanalyse als auch mit der klassischen Hautfaltenmethode bestimmt. Zusätzlich wurden Blut- und Urinproben zur Beurteilung des Flüssigkeitshaushaltes genommen und eine ¹H-NMR-Spektroskopie des Urins zum Nachweis eines erhöhten Kohlenhydrat-, Fett- oder Eiweissstoffwechsels durchgeführt. Das Körpergewicht nahm um 1.9 kg ab. Während die errechnete Muskelmasse um 0.1 kg zunahm, nahm die errechnete Fettmasse um 0.2 kg (anthropometrische Methode) resp. 3.1 kg (BIA) ab. Das errechnete Körperwasser nahm um 1.2 l zu. Während Hämatokrit, Harnstoff und spezifisches Gewicht des Urins zunahmen, sank das Natrium im Blut ab. Das Plasmavolumen nahm um 19% ab. Die ¹H-NMR-Spektroskopie des Urins zeigte nach der Belastung einen Anstieg der Ketonkörper. Um einen Abbau der Muskelmasse objektivieren zu können, muss der Ausgangswert des Körperwassers abgewartet werden, um keine Fehlinterpretation aufgrund der Methoden zu machen. Unklar bleibt, wieso es zu einer Einlagerung von Wasser kam. In weiteren Untersuchungen könnten zusätzliche Methoden wie DEXA, Muskelbiopsien und Bestimmung von weiteren Blut- und Urinparametern Auskunft geben, ob effektiv und wie viel Muskelmasse abgebaut wird und ob Abbauprodukte der Muskulatur die Nierenfunktion einschränken und somit zu einer Wasserretention führen.



2012 ◽  
Vol 3 (1) ◽  
pp. 38-40
Author(s):  
Dr. Deshworjit Singh Ningombam ◽  
◽  
Sanjita Chanu Konsam ◽  
Potsangbam Kumar Singh Potsangbam Kumar Singh


2002 ◽  
Vol 715 ◽  
Author(s):  
T. Su ◽  
Robin Plachy ◽  
P. C. Taylor ◽  
S. Stone ◽  
G. Ganguly ◽  
...  

AbstractWe study the H NMR line shapes of a sample of a-Si:H under several conditions: 1) as grown, 2) light-soaked for 600 hours, and 3) light-soaked followed by annealing at different temperatures. At T = 7 K, the NMR line shape of the sample after light soaking exhibits an additional doublet compared to that of the sample as-grown. This doublet is an indication of a closely separated hydrogen pair. The distance between the two hydrogen atoms is estimated to be about (2.3 ± 0.2) Å. The concentration of these hydrogen sites is estimated to be between 1017 and 1018 cm-3 consistent with ESR measurements of the defect density after light soaking. This doublet disappears after the sample is annealed at 200°C for 4 hours.



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