The structure of the major urinary metabolite of prostaglandin E2 in man

This letter reports the structure of the major urinary metabolite formed from prostaglandin E2 (PGE2) in humans. Radiolabeled PGE2 was injected intravenously into male subjects. 50% of the radioactivity was recovered in urine during the first 5 hours and less than 3% during the following 12 hours. The urine was acidified, and this extract was subjected to reversed-phase partition chromatography. Formation of the major metabolite (depicted stereochemically in the text) from PGE2 involved 4 steps of reactions: 1) dehydrogenation of the alcohol group in the side chain; 2) reduction of the trans double bond; 3) 2 steps of beta oxidation; and 4) delta oxidation.     

Total synthesis of the ethyl ester of the major urinary metabolite of prostaglandin E(2)

The preparation of the ethyl ester of the major urinary metabolite of prostaglandin E(2) 3 is described. The key step is the kinetic opening of the TBS-protected bicyclic ketone 7 with thiophenol.     

Mass spectra of n-butylboronate ester derivatives of the major metabolite of prostaglandin F

The EI mass spectra of six n-butylboronate ester derivatives of the major metabolite of prostaglandins F_1α and F_2α (PGF-M) are presented and discussed. Proposed ion assignments and fragmentation pathways are based on substituent shifts, on data from a deuterium-labeled methoxime derivative and on the analysis of collision-induced dissociation spectra of selected ions. Fragment ions suitable for identification and quantification of PGF-M in a biological matrix and diagnostically valuable ions for structure recognition are proposed.     

The structure of Tl2F2 from photoelectron spectroscopy

The photoelectron spectra of thallium fluoride monomer and dimer have been obtained. Two different oven techniques were used to generate the molecular beam. The resulting spectra of mixtures of the two species were separated into monomer and dimer components. A comparison of the Tl₂F₂ spectrum with semi-empirical molecular orbital calculations suggests that the dimer structure is rhombic.     

The electronic structure of ArF and Ar2F

Calculations have been performed on the electronic structure, potential energy curves and radiative transition probabilities of ArF and Ar₂F. Our predicted emission spectra for ArF indicates that only the B²Σ⁺_{$\text{1}\text{2}$} → X²Σ⁺_{$\text{1}\text{2}$} transition exhibits a large transition moment and hence a short (≈5 ns) radiative lifetime. Calculations for Ar₂F indicate that the bound upper ionic state has ²B₂ symmetry with ArAr and ArF bond lengths similar to those in the corresponding diatomic species. The terminating state also has ²B₂ symmetry and this polyatomic system should exhibit a relatively long radiative lifetime (≈200 ns)     

Analytical aspects of urinary prostaglandin determination

Conclusions The causes of the altered prostaglandin excretion in diabetic ketoacidosis are complex: hypovolaemia, renal hypoperfusion, enhanced diuresis, tubular overload and acidosis. We suggest that the most informative urinary PG determination is that of 13,14-dihydro-15-keto-PGE₂-transformed to bicyclic-PGE₂ by means of the RIA technique.

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Analytische Aspekte der Urinprostaglandinbestimmung

     

Mass fragmentographic determination of prostaglandin F2 alpha in human and rabbit urine

Analysis of prostaglandin F2 alpha (PGF2 alpha) in urine is a useful indicator of renal prostaglandin synthesis. A mass fragmentographic method for PGF2 alpha analysis in human urine was developed using [3,3,4,4-2H4]PGF2 alpha as an internal standard and carrier. PGF2 alpha was extracted from urine (20 ml) with chloroform, purified by preparative thin-layer chromatography and converted to the methyl ester trimethylsilyl ether before analysis by gas chromatography--mass spectrometry. The specificity of the urine analysis was demonstrated by retention time and the use of two pairs of fragments m/e 494/498 and 513/517 with the same results. The coefficient of variation for duplicate analysis averaged 12.6%, n = 17. Urine from recumbent women contained 4.9 +/- 2.6 (S.D.) ng/ml or 4.1 +/- 1.0 ng PGF2 alpha per mg creatinine (n = 10) with little diurnal variation. Male urine contained 5.0 +/- 2.7 (S.D.) ng/ml or 3.7 +/- 2.1 ng/mg creatinine (n = 10). Similar concentrations were found in boys and in girls. These observations indicate that urinary PGF2 alpha originates from the kidneys with little contribution from the male accessory sexual glands. This method can also be applied to analysis of PGF2 alpha in rabbit urine.     

Isolation and identification of beta-hydroxyethylaprophen: a urinary metabolite of aprophen in rats

The metabolism of the anticholinergic drug aprophen was studied in rats after oral administration via stomach intubation. beta-Hydroxyethylaprophen, a major urinary metabolite of aprophen, was isolated and identified by normal-phase high-performance liquid chromatography and electron ionization mass spectrometry. More than 22% of the parent drug was recovered and quantified over a 72-h collection period. Results show that 2,2-diphenylpropionic acid, another major metabolite of aprophen which lacks anticholinergic properties, was also isolated and identified in this study. Experiments are currently underway to synthesize and test the anticholinergic properties of beta-hydroxyethylaprophen in mammals.     

The structure of a triclinic form of octafluoroselenanthrene, (C6F4)2Se2

Octafluoroselenanthrene exists in two different cyrstal forms, monoclinic and triclinic. It is shown here that the molecular structure in the triclinic modification is very similar to that found previously in monoclinic crystals.     

Pb3Al2F12: Crystal structure of a cyclo-fluoroaluminate related to Ba3Al2F12

Pb₃Al₂F₁₂ is a fluorometalate obtained in single-crystal form by hydrothermal synthesis. It crystallizes in the monoclinic system, space group P 2₁/n, with a = 9.435(6) Å, b = 9.610(5) Å, c = 10.100(9) Å, β = 90.59(5)°, V = 915.7(2) ų, Z = 4. The structure was solved from single crystal using 3 044 unique reflections (MoKα, λ = 0.71073 Å), R = 0.0463, R_w = 0.0465. The structure exhibits isolated tetrameric groups of octahedra encaged in a subnetwork of independent fluoride polyhedra and is related to that of Ba₃Al₂F₁₂. A discussion about the existence and the structure of A₃M₂F₁₂ compounds is given.     

The structure and phase transitions in oxyfluoride (ND4)2MoO2F4

Single crystals of (ND₄)₂MoO₂F₄ containing 95% deuterium were produced by repeated recrystallization of (NH₄)₂MoO₂F₄ in heavy water. The effect of deuteration on the parameters of successive phase transitions was investigated by differential scanning microcalorimetry and polarization optics. X-ray analysis of the original and distorted phases was performed. It was found that deuteration does not change the sequence of crystal phases typical for (NH₄)₂MoO₂F₄, but leads to a shift in the phase transition Cmcm → Pnma towards the tricritical point. The mechanism of phase transitions in (ND₄)₂MoO₂F₄ was associated with both the ordering and the displacement of atoms.