Phosphonylated azaheterocycles are an important class of compounds with high biological potential as conformationally restricted bioisosteres of amino acids. Therefore, it is of interest to synthesize conformationally constrained amino phosphonates. We wanted to investigate possible routes via ring opening of alpha-amino phosphonates with an oxanorbornene skeleton, as these can be synthesized w...

v2o5/sio2 nanoparticles was prepared via an one-pot sol gel method from vanadyl- acetylacetonate and tetraethylorthosilicate in refluxing meoh, followed by calcination at 700 °c for 2 hours. the resultant nanoparticles was characterized by means of scanning electron microscopy (sem), transmission electron microscopy (tem), x-ray diffraction (xrd), tga and ftir techniques. rapid and efficient ar...

nifedipine (nif), a 1,4-dihydropyridine calcium channel antagonist, undergoes photo-degradation to dehydro-nifedipine (dnif) upon exposure to ultraviolet (uv) light and to the nitroso analogue of dehydro-nifedipine (ndnif) when exposed to sunlight or some kinds of artificial lights. nif photo-degradation products do not contribute to clinical activity, thus prevention of photo-degradation of ni...

This feature article describes the recent conceptual understanding of aromaticity and its contribution to thermodynamics in catalytic process involving dearomatization aromatization steps via metal-ligand cooperation.

Solid deposits from commercially available high-pressure diesel injectors (HPDI) were analyzed to study the solid deposition from diesel fuel during engine operation. The structural and chemical properties of injector deposits were compared to those formed from the thermal oxidative stressing of a diesel fuel range model compound, n-hexadecane at 160 degrees C and 450 psi for 2.5 h in a flow re...

The clinical effects and pharmacokinetics of ketamine, administered as an i.v. infusion, were studied in 31 patients. Anaesthesia was induced with ketamine 2 mg kg-1 i.v. and maintained using an i.v. infusion of ketamine, supplemented by nitrous oxide. The plasma concentrations of ketamine, nor-ketamine and dehydro-nor-ketamine were analysed using gas-liquid chromatography. The average maintena...

Cyclo(His-Phe) was effectively converted to its dehydro derivatives by the enzyme of Streptomyces albulus KO-23, an albonoursin-producing actinomycete. Two types of dehydro derivatives were isolated from the reaction mixture and identified as cyclo(DeltaHis-DeltaPhe) and cyclo(His-DeltaPhe). This is the first report on cyclo(His-DeltaPhe) and the enzymatic preparation of both compounds. Cyclo(D...

A simple, rapid and sensitive ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed for the simultaneous determination of cilostazol and its pharmacologically active metabolite 3,4-dehydro cilostazol in human plasma using deuterated analogs as internal standards (ISs). Plasma samples were prepared using solid phase extraction and chromatographic...

A novel angucycline metabolite, 2,3-dehydro-UWM6, was identified in a jadH mutant of Streptomyces venezuelae ISP5230. Both UWM6 and 2,3-dehydro-UWM6 could be converted to jadomycin A or B by a ketosynthase alpha (jadA) mutant of S. venezuelae. These angucycline intermediates were also converted to jadomycin A by transformant of the heterologous host Streptomyces lividans expressing the jadFGH o...