Search Within


Applied Filters:
Showing 1-24 of 24 results for "280992" within Papers
Fast Hetero-Diels- Alder Reactions Using 4-Phenyl-1, 2, 4-triazoline-3, 5-dione (PTAD) as the Dienophile
Celius TC
Journal of Chemical Education, 87(11), 1236-1237 (2010)
Shinichi Sato et al.
ACS chemical biology, 10(11), 2633-2640 (2015-09-12)
Tyrosine-specific chemical modification was achieved using in situ hemin-activated luminol derivatives. Tyrosine residues in peptide and protein were modified effectively with N-methylated luminol derivatives under oxidative conditions in the presence of hemin and H2O2. Both single and double modifications of
4-Phenyl-1, 2, 4-triazoline-3, 5-dione: a novel dehydrogenating agent for dihydropyridazines
Klindert T and Seitz G
Synthetic Communications, 26(13), 2587-2596 (1996)
A K Batta et al.
Steroids, 62(11), 700-702 (1997-11-20)
Synthesis of [3 alpha-3H]7-dehydrocholesterol is described via protection of the 5,7-diene system in 7-dehydrocholesterol as the Diels-Alder adduct with 4-phenyl-1,2,4-triazoline-3,5-dione followed by oxidation of the hydroxyl group to give the 3-oxo adduct. Reduction of the keto adduct with [3H]sodium borohydride
Rebecca L Grange et al.
Chemistry (Weinheim an der Bergstrasse, Germany), 16(29), 8894-8903 (2010-06-24)
A detailed examination of [4+2] cycloaddition reactions between 1,8-disubstituted cyclooctatetraenes and diazo compounds revealed that 4-phenyl-1,2,4-triazole-3,5-dione (PTAD) reacts to form either 2,3- or 3,4-disubstituted adducts. The product distribution can be controlled by modulating the electron density of the cyclooctatetraene. Unprecedented
Zhican Wang et al.
Endocrinology, 155(6), 2052-2063 (2014-03-20)
25-Hydroxyvitamin D3 (25OHD3) is used as a clinical biomarker for assessment of vitamin D status. Blood levels of 25OHD3 represent a balance between its formation rate and clearance by several oxidative and conjugative processes. In the present study, the identity
Anders H Berg et al.
Clinical chemistry, 61(6), 877-884 (2015-04-30)
24,25-Dihydroxyvitamin D [24,25(OH)2D] is a metabolite of 25-hydroxyvitamin D (25D). Blacks frequently have low total 25D without manifestations of vitamin D deficiency, suggesting that total serum 25D may incorrectly reflect vitamin D status in different racial groups. The ratio of
N A Ayers et al.
The Biochemical journal, 331 ( Pt 1), 137-141 (1998-05-16)
The dienophile 4-phenyl-1,2,4-triazoline-3,5-dione (PTD) was identified as a novel protein cross-linker, and utilized as a conformational probe of phosphorylase b kinase (PhK), a hexadecameric enzyme with the subunit composition (alphabetagammadelta)4. In its reaction with this enzyme, PTD produced five major
B Yeung et al.
Journal of chromatography, 645(1), 115-123 (1993-08-13)
A mass spectrometric method for the detection of vitamin D3 metabolites is described. This method involves the derivatization of the metabolites by cycloaddition with 4-phenyl-1,2,4-triazoline-3,5-dione, followed by their characterization by continuous-flow fast atom bombardment (CF-FAB) tandem mass spectrometry (MS-MS) and
Matthew D Teegarden et al.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences, 991, 118-121 (2015-05-09)
The detection of 25-hydroxyvitamin D at low levels in biological samples is facilitated by the use of chemical derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) in concert with liquid chromatography-tandem mass spectrometry (LC-MS/MS). This mode of analysis is notably hampered by chromatographic co-elution
A reinvestigation of the reaction of allylsilanes with N-phenyltriazolinedione: stereoselective synthesis of substituted urazoles by [3+2] cycloaddition
Raudra T. Dey
Tetrahedron Letters, 48, 6671-6671 (2007)
Daniela Max et al.
Molecular nutrition & food research, 58(2), 343-352 (2013-08-22)
Epidemiologic data reveal associations between low serum concentrations of 25-hydroxyvitamin D (25(OH)D) and higher risk of falls and muscle weakness. Fetal stage is critical for the development of skeletal muscle, but little information is available on the impact of maternal
Location of conjugated diene position in an aliphatic chain by mass spectrometry of the 4-phenyl-1,2,4-triazoline-3,5-dione adduct.
D C Young et al.
Analytical chemistry, 59(15), 1954-1957 (1987-08-01)
Tatsuya Higashi et al.
Analytical and bioanalytical chemistry, 403(2), 495-502 (2012-03-01)
The utility of Diels-Alder derivatization with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) for liquid chromatography/electrospray ionization tandem mass spectrometry of conjugated linoleic acids (CLAs) was examined. PTAD rapidly reacted with the CLAs, and the resulting derivatives were highly responsive in electrospray ionization mass spectrometry
A S Weiskopf et al.
Journal of mass spectrometry : JMS, 36(1), 71-78 (2001-02-17)
The structural specificity of vitamin D derivatization by PTAD (4-phenyl-1,2,4-triazoline-3,5-dione) was probed using synthetic analogues and ion trap mass spectrometry. EB 1089, a vitamin D(3) analogue which contains a second site for Diels--Alder cycloaddition on its side-chain, allowed the examination
Anders Burild et al.
Scandinavian journal of clinical and laboratory investigation, 74(5), 418-423 (2014-04-23)
Serum 25-hydroxy-vitamin D is the established biomarker of vitamin D status although serum concentrations of vitamin D and 24,25-dihydroxyvitamin D may also be of interest to understand the in vivo kinetics of serum 25-hydroxyvitamin D. An LC-MS/MS method was developed
N-Phenyltriazolinedione as an efficient, selective, and reusable reagent for the oxidation of thiols to disulfides
Angelos C, et al.
Tetrahedron Letters, 47, 9211-9211 (2006)
B Yeung et al.
Biochemical pharmacology, 49(8), 1099-1710 (1995-04-18)
1,25-Dihydroxy-16-ene vitamin D3 is a synthetic analog of 1,25-dihydroxyvitamin D3, the most physiologically active metabolite of vitamin D3. The renal metabolism of 1,25-dihydroxy-16-ene vitamin D3 had been studied previously using a perfused rat kidney system [Reddy et al., Bioorg Med
Grant A Abernethy
Analytical and bioanalytical chemistry, 403(5), 1433-1440 (2012-03-24)
A method for analysing vitamin D(3) (VD3, cholecalciferol) has been established and validated. This method is rapid and cost effective and is intended for use in quality control in the manufacture of fortified infant formulae and milk powders. Milk or
K Søndergaard et al.
Chemistry (Weinheim an der Bergstrasse, Germany), 7(11), 2324-2331 (2001-07-12)
The 5-aza-6-deoxy analogue of castanospermine (+/-)-5a and its 1-epimer (+/-)-5b was synthesized. The synthesis started from the known compound 5-benzyloxy-7-hydroxyhepta-1,3-diene, which was protected and subjected to Diels-Alder reaction with 4-phenyl-1,2,4-triazoline-3,5-dione to give two epimeric adducts. One of these was transformed
4-Phenyl-1, 2, 4-triazole-3, 5-dione as a novel and reusable reagent for the aromatization of 1, 4-dihydropyridines under mild conditions
Zolfigol MA, et al.
Tetrahedron Letters, 46(33), 5581-5584 (2005)
Darryl Eyles et al.
Clinica chimica acta; international journal of clinical chemistry, 403(1-2), 145-151 (2009-02-24)
Low levels of 25 hydroxyvitamin D (25OHD) during early development is associated with a range of adverse health outcomes. While a number of methods exist to measure 25OHD in sera, none have been specifically developed to examine dried blood spots
Ahmad Basheer et al.
The Journal of organic chemistry, 73(1), 184-190 (2007-12-13)
The reaction of 16 enols of amides with 4-phenyl-1,2,4-triazoline-1,3-dione gave open chain adducts rather than the [2 + 2] cycloadducts with a hemiaminal moiety, both in solid state and in solution. This assignment is based on X-ray crystallography, (1)H and
Derek R Boyd et al.
Organic & biomolecular chemistry, 6(7), 1251-1259 (2008-03-26)
A series of twelve benzoate esters was metabolised, by species of the Phellinus genus of wood-rotting fungi, to yield the corresponding benzyl alcohol derivatives and eight salicylates. The isolation of a stable oxepine metabolite, from methyl benzoate, allied to evidence
Page 1 of 1