Effect of the systemic versus inhalatory administration of synthetic glucocorticoids on the urinary steroid profile as studied by gas chromatography-mass spectrometry

This paper presents a gas chromatography-mass spectrometry (GC-MS) study carried out on human urine to verify whether the administration of glucocorticoids can affect the urinary steroid profile, and especially the levels of endogenous glucocorticoids, androgens and their main metabolites.Betamethasone and beclomethasone, administered either systemically (per os or i.m.) or locally (by inhalation) have been studied. The determination of the urinary levels of endogenous glucocorticoids and androgens was carried out by GC-MS in electron impact ionization mode. Data were evaluated taking into account the baseline individual variability, and compared with values obtained on a control group.Detectable differences were recorded in the steroids metabolites excretion profiles between men and women. The circadian variability of the steroid profile was the same for both sexes, showing a maximum during the morning hours. After systemic treatment with synthetic glucocorticoids, the relative urinary concentrations of corticosteroids, androgens and of their metabolites were significantly altered, recording a transient decrease of the concentration of cortisol and tetrahydrocortisol and a parallel, although less pronounced, increase of the concentration of testosterone, epitestosterone and related androgenic steroids; while no effects were recorded if the administration was by inhalation.     

Electrochemical measurement of mercury concentration profiles in the pore-waters of sediments of the Venice Lagoon by ion-exchange voltammetry at polymer modified electrodes

Glassy carbon electrodes modified with coatings of poly-[1-methyl-3-(pyrrol-1-ylmethyl)pyridinium], poly-MPP, were employed for preconcentrating and detecting the anionic complex HgCl4(2-), which is the prevailing inorganic Hg(II) species in salt waters such as the pore-waters of sediments here examined. The application of ion-exchange voltammetry at poly-MPP coated electrodes in combination with an in situ pore-water sampler allowed the measurement of concentration vs. depth profiles for mercury dissolved in the pore-waters of a salt-marsh and of a mud-flat located in a polluted area of the Venice Lagoon. The trends of the mercury profiles are discussed in comparison with the trends measured from the same location for other trace metals (Zn, Cd, Cu and Pb) and reduced species such as S(-II) and Fe(II).     

Semi-empirical study of a reduced rubredoxin analogue

Molecular orbitals were determined for an analogue of reduced rubredoxin in an iterative extended Hückel (self-consistent charge) calculation. Zero field splittings and Mössbauer spectral parameters were then computed. The results are compared with available experimental data.     

Development and characterization of a solvent extraction-gas chromatographic/mass spectrometric method for the analysis of perfluorooctanesulfonamide compounds in solid matrices

A method utilizing solvent extraction and analysis by gas chromatography-positive chemical ionization mass spectrometry (SE-GC-PCIMS) was developed for the analysis of three neutral hydrophobic perfluorooctanesulfonamide compounds [perfluorooctanesulfonamide (PFOSA), N-ethyl perfluorooctanesulfonamide (N-EtPFOSA), and N,N-diethyl perfluorooctanesulfonamide (N,N-Et2PFOSA)]. These compounds are suspected metabolic precursors of perfluorooctane sulfonate. The SE-GC-PCI-MS method was used to analyze all three perfluorooctanesulfonamides in fast food, fish, and Arctic marine mammal liver samples. The SE-GC-PCI-MS method produced relatively higher recoveries of the analytes (averaging 83 +/- 6%, 84 +/- 9%, and 89 +/- 19% for N,N-Et2PFOSA, N-EtPFOSA, and PFOSA, respectively) with lower coefficients of variation, and less susceptibility to matrix effects, than ion pair extraction-liquid chromatography-tandem mass spectrometric methods. Method detection limits (MDLs) were 100, 120, and 250 pg/g for N,N-Et2PFOSA, N-EtPFOSA, and PFOSA, respectively. The three compounds were found at concentrations ranging from below the MDL to 22 ng/g wet weight in fast food, fish, and Arctic marine mammal liver samples.     

Substitution and addition reactions of organic substrates with hypofluorous acid

The chemical reactions of hypofluorous acid with aromatic and olefinic substrates show considerable variety. Hypofluorous acid reacts with naphthalene to give 1-naphthol, 2-naphthol and 1,4-naphtho-quinone; with benzo[b]thiophen to give the 1,1-dioxide; with trans-stilbene to give threo-2-fluoro-1-hydroxy-1, 2-diphenylethane, benzophenone and diphenylacetaldehyde; and with cholesteryl acetate to give the two epoxides (α:β = 6.3:1) and two fluorohydrins (6β-fluoro-5β-o1 and 5α-fluoro-6β-o1).     

Solid phase synthesis of 6-acylamino-1-alkyl/aryl-4-oxo-1,4-dihydrocinnoline-3-carboxamides

6-Acylmino-1-alkyl/aryl-4-oxo-1,4-dihydrocinnoline-3-carboxamides were synthesized in parallel from 6-nitro-4-oxo-1,4-dihydrocinnoline-3-carboxylic acid. The latter formed amides with amines bound to polystyrene-based resins via acid-labile linkers. N1 and N2-alkylation, followed by alkyl migration yielded only N1-alkylated products. Reduction of the 6-nitro group and acylation concluded the synthesis.     

Determination of Diclofenac in Urine Samples by Molecularly‐Imprinted Solid‐Phase Extraction and Adsorptive Differential Pulse Voltammetry

A molecularly imprinted polymer for diclofenac (DCF) was prepared by thermal polymerization over silica beads using 2‐(dimethylamino)ethyl‐methacrylate as functional monomer. After silica elimination by HF treatment, the polymer was applied to the selective solid‐phase extraction of the drug from urine followed by its quantification by adsorptive differential pulse voltammetry. Results indicate that the drug could be selectively extracted from the sample and quantified at clinically relevant concentrations (μg/mL).     

Dynamic behaviour and X-ray analysis of chiral η-allylpalladium complexes. II

The DANTE technique and NOESY two-dimensional method have been employed to observe the isomerization of the chiral cationic complex [Pd(η³-CH₂CMeCH₂(P-P′)]⁺ (1a), where P-P′ = the chiral chelating ligand (S)(N-diphenylphosphino)(2-diphenylphosphinoxymethyl)pyrrolidine. The rate constant was found to be 0.5 s⁻¹ in CHCl₃ at 295 K and 1.50 s⁻¹ in the presence of added free ligand. In the latter case the epimerization proceeds by a π-σ-π mechanism via the intermediacy of a primary η¹-allylpalladium complex. Although the intermediate was not detected, the NMR findings reveal that it has the allylic terminus η¹-bonded to palladium. The structure of 1a in its PF₆⁻ salt has been determined. The compound crystallizes in the orthorhombic space group P2₁2₁2₁ with a 10.029(4) b 19.203(8) c 36.115(6) Å, Z = 8, R = 0.0572 and R_w = 0.0712 for 3716 observed reflections with I > 3σ(I).     

A study of the OH- -induced beta-elimination reactions of 2-(4-chloroethyl)pyridine, 2-(2-chloroethyl)pyridine, 1-methyl-2-(4-chloroethyl)pyridinium iodide and 1-methyl-2-(2-chloroethyl)pyridinium iodide in acetonitrile/water

Second-order rate constants have been determined for the title reactions in OH(-)/H(2)O and in OH(-)/ (CH(3)CN/H(2)O) [30/70, 60/40, and 85/15 (v/v) mixtures]. A relatively small increase in reactivity is observed for the four substrates upon increasing the percentage of CH(3)CN in the solvent mixture. The methyl activating factors (/) are also slightly affected by the solvent composition. On the other hand, the high acceleration of the reaction by methylation of the pyridine ring amounts to 10(4)-10(6) according to an E1cb mechanism.     

A new procedure for the enantioselective vinylogous aldol reaction of Chan’s diene

Chiral δ-hydroxy-β-ketoesters are easily available through the enantioselective vinylogous aldol reaction of Chan’s diene promoted by a SiCl₄/chiral phosphoramide catalytic system. The procedure is conveniently exploited for a very rapid approach to (+)-kavain, a natural bio-active -pyrone compound.