A population-based resource for intergenerational metabolomics analyses in pregnant women and their children: the Generation R Study

INTRODUCTION: Adverse exposures in early life may predispose children to cardio-metabolic disease in later life. Metabolomics may serve as a valuable tool to disentangle the metabolic adaptations and mechanisms that potentially underlie these associations. OBJECTIVES: T

Curing cats with Feline Infectious Peritonitis with an oral multi-component drug containing GS-441524

Feline infectious peritonitis (FIP) caused by feline coronavirus (FCoV) is a common dis-ease in cats, fatal if untreated, and no effective treatment is currently legally available. The aim of this study was to evaluate efficacy and toxicity of the multi-component drug Xraphconn$^{®}$ in vitro and as oral treatment in cats with spontaneous FIP by examining survival rate, development of clinical and laboratory parameters, viral loads, anti-FCoV antibodies, and adverse effects. Mass spectrometry and nuclear magnetic resonance identified GS-441524 as an active component of Xraphconn$^{®}$. Eighteen cats with FIP were prospectively followed up while being treated orally for 84 days. Values of key parameters on each examination day were compared to values before treatment initiation using linear mixed-effect models. Xraphconn$^{®}$ displayed high virucidal activity in cell culture. All cats recovered with dramatic improvement of clinical and laboratory parameters and massive reduction in viral loads within the first few days of treatment without serious adverse effects. Oral treatment with Xraphconn$^{®}$ containing GS-441524 was highly effective for FIP without causing serious adverse effects. This drug is an excellent option for the oral treatment of FIP and should be trialed as potential effective treatment option for other severe coronavirus-associated diseases across species

Derivatize, Racemize, and Analyze-an Easy and Simple Procedure for Chiral Amino Acid Standard Preparation for Enantioselective Metabolomics

A simple, controllable, and reproducible stereoisomerization (racemization and epimerization) protocol for the preparation of scalemic α-amino acid mixtures from stereoisomerically pure standards was developed. Simply derivatize your amino acids with a racemization tag that incorporates a urea bond on the N-terminus of the target amino acid and incubate at elevated temperatures up to 95 °C for defined time periods until the targeted d-amino acid levels are obtained. The racemization tags investigated were 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC), aminophenyl-N-hydroxysuccinimidyl carbamate (AC), and 3-aminopyridyl-N-hydroxysuccinimidyl carbamate (APC). Employing this method, it was possible to create a ready-to-use, tailor-made chiral uniformly 13C and 15N labeled [U-13C15N]-amino acid standard with the desired d-amino acid percentage within minutes or hours without sample cleanup. A racemization time of 30 min at 95 °C will lead to a d-amino acid level of 1–5%, while 6 h at 95 °C provides 15–30% d-amino acids. Racemization occurs due to imine formation at the chiral carbon atom bound to the urea-linking group without decomposition of labile amino acids such as Asn, Gln, Trp, Cit, and theanine. For amino acids possessing two chiral centers such as dl-Ile or dl-Thr, only the epimerization of isomers with different stereochemistry at the second chiral center will produce all four possible isobaric enantiomers. All measurements were performed on the zwitterionic Chiralpak ZWIX­(+) column using a dual hydro-organic flow gradient combined with HPLC-ESI-QTOF-MS analysis. This new racemization method solves the problem of (enantioselective) matrix effects and inaccurate results in LC-MS based enantioselective metabolomics and warrants full MS-compatibility

Preparation of Phosphonic Acid Analogues of Proline and Proline Analogues and Their Biological Evaluation as δ1-Pyrroline-5-carboxylate Reductase Inhibitors

Racemic 1-hydroxy-3-butenyl-, 3-chloro-1-hydroxypropyl-, and 3-bromo-1-hydroxypropylphosphonate and the corresponding (S)-enantiomers obtained by lipase-catalyzed resolution of the respective racemic chloroacetates were subjected to functional group manipulations. These comprised ozonolysis, Mitsunobu reactions with hydrazoic acid and N-hydroxyphthalimide, alkylation of hydrazine derivative, removal of phthaloyl group followed by intramolecular substitution, and global deprotection to deliver the racemates and (R)-enantiomers (ee 92-99% by chiral high-performance liquid chromatography) of pyrrolidin-2-yl-, oxazolidin-3-yl-, oxazolidin-5-yl-, pyrazolidin-3-yl-, and 1,2-oxazinan-3-ylphosphonic acids. These phosphonic acids were evaluated as analogues of proline and proline analogues for the ability to inhibit γ-glutamyl kinase, δ1-pyrroline-5-carboxylate synthetase, and δ1-pyrroline-5-carboxylate reductase. Only the latter enzyme was inhibited by two of them at concentrations exceeding 1 mM

Conversion of nitriles to 1-aminophosphonic acids and preparation of phosphahomocysteines of high enantiomeric excess

<p></p> <p>A variety of nitriles was reduced to diisobutylaluminum salts of aldimines, to which diisopropyl phosphite was added. The corresponding 1-aminophosphonates were either deprotected to give racemic 1-aminophosphonic acids or reacted with Boc₂O to yield <i>N</i>-Boc-protected 1-aminophosphonates. The enantiomers of 2-benzylthio-1-(<i>t</i>-butoxycarbonylamino)propylphosphonate were obtained from the racemate by chiral HPLC and converted to phosphonic acid analogs of (<i>R</i>)- and (<i>S</i>)-homocysteine, (<i>R</i>)- and (<i>S</i>)-2-aminobutyric acid and (<i>S</i>)-methionine, all of ee >97% as determined by chiral HPLC.</p