Two liquid chromatography–tandem mass spectrometry (LC–MS/MS) methods were developed for the determination of streptomycin (STR) and its derivative dihydrostreptomycin (DHSTR) in milk and honey. These aminoglycoside antibiotics are used as veterinary drugs. In the EU, the presence of dihydro- ...
An HPLC–PAD method using a gold working electrode and a triple-potential waveform was developed for the simultaneous determination of streptomycin and dihydrostreptomycin in veterinary drugs. Glucose was used as the internal standard, and the triple-potential waveform was optimized using a fact...
We report the preparation of the 7α-cyano derivative of the isomeric (17α,20E/Z)-[125I]iodovinyl-19-nortestosterones (IVNT) together with their binding affinity for the androgen receptor (AR) and their biodistribution in two different animal models. The cyano group was introduced at the 7α-po...
We studied the pharmacokinetics of 7α-methyl-19-nortestosterone (MENT), a potent synthetic androgen, administered by subdermal implants. The implants contained 112 ± 4 mg of MENT acetate in a polyethylene vinyl acetate copolymer. MENT acetate released from the implants is rapidly hydrolyzed to...
Testosterone is an essential part of all regimens for hormonal male contraception tested to date. Initial efficacy trials revealed that the half-life of the testosterone preparations available at that time was too short to be used for male contraception. The ensuing search for long-acting prepar...
Urine and plasma samples of non-castrated, cryptorchid and castrated boars were analysed in order to establish the endogenous concentration of 19-nortestosterone. A combination of three different analytical techniques was used in this work. ELISA and gas chromatography were used for quantitation...
For almost two decades we have known that enzymatic hydrolysis of “normal” urine samples from the entire male horse using Escherichia coli (E. coli) followed by solvolysis (ethyl acetate:methanol:sulphuric acid) results in the detection of significant amounts of estr-4-ene-3,17-dione (19-noran...
The synthetic anabolic androgenic steroid 19-nortestosterone is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA) due to its performance-enhancing effects. Today, doping controls focus predominantly on one main urinary metabolite, 19-norandrosterone glucuro...
Novel 16-hydroxymethyl-19-nortestosterone diastereomers were prepared by Birch reduction from the corresponding 3-methoxy-16-hydroxymethylestra-1,3,5(10)-trien-17-ol isomers with known configurations. The synthesized compounds are 16α- and 16β-hydroxymethyl-substituted 19-nortestosterone and t...
Quaternary amino groups were introduced into chitin and chitosan to obtain O-(2-hydroxy-3-trimethylammonium)propyl chitin (OHT-chitin) and N-(2-hydroxy-3-trimethylammonium)propyl chitosan (NHT-chitosan). They were characterized by FTIR spectra, and GPC. The molecular weight Mw of OHT-chitin and ...
Superparamagnetic iron oxide nanocrystals (SPION) and their colloidal solutions of magnetic nanoparticles (ferrofluid) appear to contribute to the magnetite imaging applications. Here we present an aqueous ferrofluid in physiological pH and its cell tracking potential. In situ coating method was...
A novel polymer-based alkaline catalyst was prepared with sodium silicate (Na2SiO3) and N-[(2-Hydroxy-3-trimethylammonium) propyl] chitosan chloride (HTCC), interlinked by epichlorohydrin (ECH), for biodiesel production. The structure and properties of the catalyst were studied by Fourier transf...
On September 22, 2008, a physician on Prince of Wales Island, Alaska, notified the Alaska Department of Health and Social Services (ADHSS) of an unusually high number of adult patients with recently diagnosed pneumonia (n = 10), including three persons who required hospitalization and one who di...
α-{3-[2-hydroxy-3-(N-methyl-N-hydroxyethylamino)propoxy]propyl}-ω-butylpolydimethylsiloxanes III with various molecular weights were prepared by epoxy addition of α-[3-(2,3-epoxy-propoxy)propyl]-ω-butylpolydimethylsiloxanes II and N-methylmonoethanolamine. At each step, the outcome compounds...
N-[(2-Hydroxy-3-Trimethylammonium) Propyl] Chitosan Chloride Derivatives (HTCC), based on low molecular weight crab chitosan, were synthesized by the alkylation reaction with a degree of substitution of 10–98%. The chemical structure was confirmed by 1H NMR and IR-spectra. Physical and chemical...
In this research work, a new extended π-conjugated chromophore of 4-[4-(4-dimethylamino-phenyl) buta-1,3-dienyl]-1-methyl pyridinium p-styrenesulfonate (DCSSS) is synthesized. The present work demonstrates that 4-[4-(4-dimethylamino-phenyl) buta-1,3-dienyl]-1-methyl pyridiniump-styrene sulfonat...
The first observation of methane photochemical production from an N,N-dimethylamino-substituted arene (DMABA: 4-(N,N-dimethylamino)benzaldehyde) is described. UV irradiation (λ>298 nm) of DMABA isolated in a solid low temperature (10 K) argon matrix was found to lead to major unimolecular fragm...
The NaI/TMSCl/Et3N-mediated condensation between 2-(pyrrol-1-yl)benzaldehydes and secondary amine hydrochlorides followed by intramolecular trapping of the resulting iminium carbon by the 2-position of the pyrrole ring afforded corresponding 9-dialkylamino-9H-pyrrolo[1,2-a]indoles generally in g...
We have developed a technique to grow 4-dimethylamino-N′-methyl-4′-stilbazolium p-bromobenzenesulfonate (DASB) with a halogen (bromine) substituent in the anion for THz-wave generation. The bulky DASB single crystals, typically measuring 3 × 3 × 0.2 mm3, are grown from a methanol solution by...
In an effort to find new methodologies to introduce difluoromethylene and trifluoromethyl moieties into organic molecules of synthetic and biological interest, tetrakis(dimethylamino)ethylene (TDAE) was found to be an effective reductant of a series of good electron-acceptors such as bromodifluo...
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