Search results for "Valine"
showing 10 items of 85 documents
Pitfalls to be considered on the metabolomic analysis of biological samples by HR-MAS
2014
HR-MAS (High-Resolution Magic AngleSpinning) is considered a powerfultechnique for metabolomic studies ofbiological samples that provides “intact”tissue spectra (Cheng et al., 1998; Waterset al., 2000; Sitter et al., 2002; Martinez-Bisbal et al., 2004; Payne et al., 2006;Coen et al., 2007; Bathen et al., 2010).The performance of HR-MAS, fol-lowed by quantitative histopathology hasdemonstrated that, despite some changes,HR-MAS can preserve approximately thetissue histopathologic features producingwell-resolved spectra of cellular metabo-lites (Cheng et al., 2000). Nevertheless,therearesomeaspectsarousedintheliter-ature about the possible biochemical andstructural changes that can occur durin…
Stereocontrolled synthesis of D-α-hydroxy carboxylic acid from L-amino acids
1987
Abstract Optically active D-α-hydroxy carboxylic acids are obtained from L-amino acids via L-α-halocarboxylic acids and their stereoselective reaction with cesium p-nitrobenzoate.
Determinants of Substrate Specificity in the NS3 Serine Proteinase of the Hepatitis C Virus
1997
AbstractProcessing of the nonstructural polyprotein of the hepatitis C virus (HCV) requires the serine-type proteinase located in the amino-terminal domain of NS3. To identify residues within NS3 determining substrate specificity, a mutation analysis was performed. Using sequence alignments and three-dimensional structure predictions, amino acids assumed to be important for specificity were replaced and the enzymes were tested in an intracellulartrans-processing assay for their effects on cleavage of an NS4B-5B substrate. For some of the substitutions at positions 133, 134, 135, 136, 138, 152, 155, 157, and 169, slightly reduced processing efficiencies were observed but in no case was the s…
Classification of vegetable oils according to their botanical origin using amino acid profiles established by direct infusion mass spectrometry.
2007
Amino acid profiles, established by direct infusion mass spectrometry, have been used to classify vegetable oils according to their botanical origin. The proteins present in hazelnut, sunflower, corn, soybean, olive, avocado, peanut and grapeseed oils were precipitated with acetone, and the residue was hydrolyzed in acid medium, diluted in a hydrochloric acid/ethanol mixture, and infused into the mass spectrometer. The spectra of the hydrolyzed protein extracts showed [M+H]+ ions of the following amino acids: glycine, alanine, serine, proline, valine, threonine, cysteine, isoleucine + leucine, aspartic acid, lysine, glutamic acid, methionine, histidine, phenylalanine, arginine and tyrosine.…
Synthesis of peptides with α,β-dehydroamino acids, VI. Synthesis ofN-benzyloxycarbonyl andN-trifluoroacetyl dipeptides of α,β-dehydro-butyrine, -vali…
1988
Condensation of Z- and TFA-amino acid amides with 2-oxo-acids, namely butanoic, 3-methylbutanoic, 4-methylpentanoic, and (3RS)-3-methylpentanoic acid, yields (in the presence of p-toluenesulfonic acid as a catalyst) Z- and TFA-dipeptides with C-terminal ΔAbu2) (1–4), ΔVal (5–8), ΔLeu (9–11), and ΔIle (12–15) (Table 1).
Ombitasvir, paritaprevir, and ritonavir, with or without dasabuvir, plus ribavirin for patients with hepatitis C virus genotype 1 or 4 infection with…
2017
Summary Background We ran a compassionate use nationwide programme (ABACUS) to provide access to ombitasvir, paritaprevir, and ritonavir, with dasabuvir, plus ribavirin for hepatitis C virus (HCV) genotype 1 infection and ombitasvir, paritaprevir, and ritonavir, plus ribavirin for HCV genotype 4 infection in patients with cirrhosis at high risk of decompensation while approval of these regimens was pending in Italy. Methods In this prospective observational study, we collected data from a compassionate use nationwide programme from March 17, 2014, to May 28, 2015. Patients with HCV genotype 1 infection and cirrhosis at high risk of decompensation were given coformulated ombitasvir (25 mg), …
Safety and efficacy of ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in patients over 65 years with HCV genotype 1 cirrhosis
2018
Purpose: To analyse safety and efficacy of treatment based on ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in the sub-group of GT1 patients older than 65 years. Methods: We collected data extracted from the ABACUS compassionate-use nationwide Italian programme, in patients with cirrhosis due to hepatitis C virus (HCV) Genotype-1 (GT1) or 4 and at high risk of decompensation. GT1-HCV-infected patients received once-daily ombitasvir/paritaprevir, with the pharmacokinetic enhancer ritonavir (25/150/100 mg) and twice-daily dasabuvir (250 mg) plus Ribavirin (RBV) (OBV/PTV/r + DSV + RBV) for 12 (GT1b) or 24 (GT1a) weeks. Endpoints were to evaluate safety and efficacy, the latter def…
Real-world experience with the all-oral, interferon-free regimen of ombitasvir/paritaprevir/ritonavir and dasabuvir for the treatment of chronic hepa…
2017
Summary Real-world studies are relevant to complement clinical trials on novel antiviral therapies against chronic hepatitis C; however, clinical practice data are currently limited. This study investigated effectiveness and safety of ombitasvir/paritaprevir/ritonavir (OBV/PTV/r)±dasabuvir (DSV)±ribavirin (RBV) for treatment of HCV genotype (GT) 1 and GT4 infection in a large real-world cohort. The German Hepatitis C Registry is an observational cohort study prospectively collecting clinical practice data on direct-acting antiviral therapies. Patients with GT1/4 infection treated with OBV/PTV/r±DSV±RBV were analysed. Effectiveness was assessed by sustained virologic response in 558 patients…
Real-world effectiveness of ombitasvir/paritaprevir/ritonavir±dasabuvir±ribavirin in patients with hepatitis C virus genotype 1 or 4 infection: A met…
2017
The direct-acting antiviral regimen of ombitasvir (OBV)/paritaprevir (PTV)/ritonavir (r) ± dasabuvir (DSV) ± ribavirin (RBV) demonstrated high rates of sustained viral response at post-treatment week 12 (SVR12) in clinical trials for treatment of hepatitis C virus (HCV) genotypes (GT) 1 and 4. To confirm the effectiveness of this regimen in the real world, we conducted meta-analyses of published literature on 30 April 2016. Freeman-Tukey transformation determined the SVR rate within GTs 1a, 1b, and 4, as well as specific SVR rates by cirrhosis or prior treatment experience status. Rates of virologic relapse, hepatic decompensation, drug discontinuation, and serious adverse events were also …
Die Bildung höherer Alkohole bei Aminosäuremangelmutanten von Saccharomyces cerevisiae III. Höhere Alkohole als Nebenprodukte der Aminosäuresynthese
1975
Summary The formation of higher alcohols as byproducts of the synthesis of threonine, isoleucine and valine was investigated using isogenic haploid and diploid mutant strains of Saccharomyces cerevisiae . Genetic markers were ade 2, leu 1. The growth rate, the formation of ethanol, the amino acid metabolism and the formation of higher alcohols were determined during fermentations in a synthetic medium. n-Propanol-1, 2-methylbutanol-l and isobutanol were synthesized parallel to ethanol formation during exponential and stationary growth phase. However, the formation of 3-methylbutanol-l from leucine was restricted to the exponential phase. A comparison of haploid and diploid strains revealed,…