A polar metabolite of 24,ZSdihydroxyvitamin DS has been generated both in vivo in rats from 25-hydroxyvitamin D3 and in vitro from 24,25-dihydroxyvitamin DS with chicken kidney homogenates. This metabolite has been isolated in pure form and identified as 1,24,25-trihydroxyvitamin Da by means of ultraviolet absorption spectrophotometry, mass spectrometry and its reactivity to periodate treatment...

Five new bis(3-hydroxy-4-pyridinone) tetradentate chelators were synthesized in this study. The structures of these tetradentate chelators were characterized by ¹H-NMR, (13)C-NMR, FT-IR, UV-vis, and mass spectral analyses. The binding abilities of these tetradentate chelators for uranyl ion at pH 7.4 were also determined by UV spectrophotometry in aqueous media. Results showed that the efficien...

Glucokinase catalyzes phosphoryl group transfer from ATP to glucose to form glucose-6-phosphate in the first step of cellular metabolism. While the location of the ATP-binding site of glucokinase was proposed recently, limited information exists on its conformation or the key amino acids involved in substrate binding. Affinity labeling with phenylglyoxal is used to probe possible Arg residues i...

Pioglitazone is an oral anti-hyperglycemic agent. It is used for the treatment of diabetes mellitus type 2. It selectively stimulates nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-gamma). It was the tenth-best-selling drug in the U.S. in 2008. This article examines published analytical methods reported so far in the literature for the determination of pioglitazone in b...

A. Introduction B. Optical and Spectrophotometric Detectors 1. Differential refractometry 2. Ultraviolet spectrophotometry 3. Fluorescence detection 4. Infrared spectrophotometric detectors 5. Spectrophotometric detection with post-column chemical reaction C. Some Miscellaneous Detection Systems 1. The mass spectrometer as an HPLC detector 2. Radioactivity detectors 3. Density, electrochemical ...

The simultaneous determination of albendazole (ABZ) and praziquantel (PZQ) was performed by different mathematical approaches: second derivative spectrophotometry (SDS), classical least squares, regression of partial least squares and principal components regression based on spectral data of drugs dissolved in methanol-hydrochloric acid solution. The detection limits for multivariate calibratio...

there are various methods for the analysis of potassium sorbate and sodium benzoate in food products, but a rapid and reliable method for identification of these preservatives in doogh (an iranian traditional dairy drink) is a procedure, in which high performance liquid chromatography (hplc) utilized and followed by uv diode array detection of the two preservatives. the aim of this case study w...

The titration of methanobactin with Cu(II) was monitored by both UV/Vis and NMR spectroscopy and indicates that the major transitions occurring when Cu(II) interacts with methanobactin involve a two-step process that is complete by about 0.6 Cu:mb. This suggests that a 2:1 complex is formed between methanobactin and copper at low copper levels. If this complex exists, it would be different than...

OBJECTIVE The aim of this study was to diagnose ectopic pregnancy in the early period by measuring cell-free fetal DNA (cffDNA) levels in maternal blood using spectrophotometry. MATERIALS AND METHODS Thirty patients with ectopic pregnancy and 30 patients with first trimester intrauterine pregnancy were enrolled in this prospective controlled study. cffDNA levels in maternal serum were measure...