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241.
Godin JP Faure M Breuille D Hopfgartner G Fay LB 《Analytical and bioanalytical chemistry》2007,388(4):909-918
We describe a new method of assessing, in a single run, 13C isotopic enrichment of both Val and Thr by gas chromatography–combustion–isotope-ratio mass spectrometry (GC–C–IRMS). This
method characterised by a rapid one-step derivatisation procedure performed at room temperature to form the N(O,S)-ethoxycarbonyl ethyl ester derivatives, and a polar column for GC. The suitability of this method for Val and Thr in in-vivo
samples (mucosal hydrolysate) was demonstrated by studying protein metabolism with two tracers (13C-valine or 13C-threonine). The intra-day and inter-day repeatability were both assessed either with standards or with in-vivo samples at
natural abundance and at low 13C isotopic enrichment. For inter-day repeatability CVs were between 0.8 and 1.5% at natural abundance and lower than 5.5%
at 0.112 and 0.190 atom% enrichment for Val and Thr, respectively. Overall isotopic precision was studied for eleven standard
amino acid derivatives (those of Val, Ala, Leu, Iso, Gly, Pro, Asp, Thr, Ser, Met, and Phe) and was assessed at 0.32‰. The
13C isotopic measurement was then extended to the other amino acids (Ala, Val, Leu, Iso, Gly, Pro, Thr, and Phe) at natural
abundance for in-vivo samples. The isotopic precision was better than 0.002 atom% per amino acid (for n = 4 rats). This analytical method was finally applied to an animal study to measure Thr utilization in protein synthesis. 相似文献
242.
Amani Jaafar Adeline Fix-Tailler Najwa Mansour Magali Allain Wassim N. Shebaby Wissam H. Faour Sima Tokajian Abdelkrim El-Ghayoury Daoud Naoufal Jean-Philippe Bouchara Gérald Larcher Ghassan Ibrahim 《应用有机金属化学》2020,34(12):e5988
The reactions of Cu (II), Zn (II) and Cd (II) chloride or bromide with (E)-1-(3,4-dimethoxybenzylidene)-4-methylthiosemicarbazone (MTSVT) lead to the formation of new complexes. They were characterized by spectroscopic studies: IR, 1H and 13C NMR. The crystal structures of the compounds [MTSVT] ( L ), [ZnBr2(MTSVT)2] ( 2 ), [CdCl2(MTSVT)2] ( 3 ) and [CdBr2(MTSVT)2.H2O] ( 4 ) were determined by X-ray diffraction. For complexes 2 – 4 , the ion is coordinated through the sulfur atom. All compounds were tested for their antifungal activity against human pathogenic fungi Candida albicans and Aspergillus fumigatus, and for their antibacterial activity against Gram (+) Bacillus subtilis and Enterococcus faecalis as well as against Gram (−) bacteria such as Paracoccus yeei and Acinetobacter baumanii. The results indicated that the metal complexes exhibited a marked enhancement in antibacterial activity compared with the parent Schiff base. 相似文献
243.