Synthesis of a 11-deoxyprostanoid in the area of preclavulones: (+-)-8,12-trans-(5Z-14Z)-9-oxo-prosta-5,14-dienoic acid from 2-allyl-2-cyclopenten-1-one.

Following our research on the arachidonic acid metabolites and their derivatives with potential biological activity, we describe the synthesis of the (+-)-8,12-trans-(5Z, 14Z)-9-oxo-prosta-5,14-dienoic acid, a 11-deoxyprostanoid correlated to the class of Preclavulones, one of the unusual families of marine eicosanoids from the coral Clavularia Viridis with considerable biological interest.

Separation and molecular weight determination of prostaglandin B1 oligomers by size-exclusion chromatography.

An efficient size-exclusion chromatographic method for the simultaneous separation and molecular weight (MW) determination of prostaglandin (PG) oligomers on Sephadex G-50 with borate buffer is described. The prostaglandins 15-keto-PGB1 and 16,16-dimethyl-15-keto-PGB1 were used for the synthesis of oligomers. MW determinations in the monomer to octamer range is based on the linear correlation between the partition coefficient and log (MW) of the oligomers. The essential role of the borate anion between the gel matrix and the oligomers is demonstrated.

Diethylhydrogensilyl-cyclic diethylsilylene derivatives in gas chromatography-mass spectrometry of prostanoids. III. F alpha-prostaglandins and thromboxane B2 derivatives.

The gas chromatographic (GC) and GC-mass spectrometric properties of the diethylhydrogensilyl-cyclic diethylsilylene (DEHS-DES) derivatives of prostaglandin (PG) F1 alpha methyl ester, PGF2 alpha methyl ester, 6-keto-PGF1 alpha methyl ester-alkyloxime and thromboxane (TX) B2 methyl ester-alkyloxime and the DES derivative of 13,14-dihydro-15-keto-PGF2 alpha methyl ester-alkyloxime were studied. When the ketonic PGs and TXB2 were converted into their methyloxime derivatives, the methylene unit values of these five prostanoid derivatives were slightly greater than those of the corresponding dimethylethylsilyl ether derivatives. When the ketonic PGs were converted into their corresponding ethyloxime derivatives, baseline separation was achieved in 20 min by use of a methylsilicone cross-linked fused-silica capillary column. The mass spectra of these derivatives were characterized by the ion at m/z 157 for F alpha prostaglandins and m/z 269 for TXB2. The major fragmentations were directed by the DES group, and other fragmentations common to the prostanoid derivatives were losses of an ethyl radical at the silicon atom, C5H11 hydrocarbon fragment, diethylhydrogensilanol and C15-C20 hydrocarbon fragment. The mass fragmentations of these prostanoid derivatives are briefly discussed. GC with high-resolution selected-ion monitoring was carried out for the TXB2 derivative at a resolution of 8000 by monitoring the ion at m/z 269.1573. A 25-pg amount of this derivative showed a well shaped doublet with a signal-to-noise ratio of more than 300:1.

Development of antibody-mediated extraction followed by GC/MS (antibody/GC/MS) and its application to iloprost determination in plasma.

A new analytical principle has been developed combining the features of both radioimmunoassay and GC/MS. Its application in eicosanoid analysis was tested with the prostacyclin analogue, iloprost. The iloprost antibody, generally employed in RIA measurements, was coupled to Sepharose 4B and used as stationary phase for extraction of the drug. Variations in recovery were corrected by using deuterated iloprost as an internal standard. The samples were derivatized and quantitated by negative-ion chemical ionization-mass spectrometry. Reproducibility was 2.3 % at the 50 pg/ml level and the limit of detection was 5 pg for 1 ml samples. With plasma volumes of up to 20 ml, 0.25 pg/ml could be determined. Antibody/GC/MS proved superior to radioimmunoassay due to its higher specificity and sensitivity and superior to GC/MS with conventional clean-up procedures because of a higher sample capacity.

Picogram detection of eicosanoids by ultraviolet absorbance after narrow-bore high-performance liquid chromatography. Comparison with conventional-bore column.

Mobile-phase variations were employed to achieve optimal separation by narrow-bore reversed-phase high-performance liquid chromatography of eleven eicosanoids. Separation and quantitation by ultraviolet absorbance at 190 nm using conventional-bore ODS columns were compared. Using the improved sensitivity obtained by means of the narrow-bore column, i.e. 250-pg detection limits of a standard solution, analysis of eicosanoids in kidney medulla was achieved. Parallel quantitation by radioactivity, using [1-(14)C]arachidonic acid as substrate, was applied.

The use of immobilized ligands and [125I]protein a for immunoassays of thromboxane B2, prostaglandin D2, 13,14-dihydro-prostaglandin E2, 5,6-dihydro-prostaglandin I2, 6-keto-prostaglandin F1 alpha, 15-hydroxy-9 alpha, 11 alpha(epoxymethano)prosta-5,13-dienoic acid and 15-hydroxy-11 alpha,9 alpha(epoxymethano)prosta-5,13-dienoic acid.

Immunoassays were developed for quantitative determination of thromboxane B2, prostaglandin D2, 13,14-dihydro-prostaglandin E2, 5,6-dihydro-prostaglandin I2, 6-keto-prostaglandin F1 alpha, 15-hydroxy-9 alpha, 11 alpha (epoxymethano) prosta-5, 13-dienoic acid and 15-hydroxy-11 alpha, 9 alpha (epoxymethano) prosta-5,13-dienoic acid. Ligands immobilized by covalent linkage to a solid support, bound homologous rabbit antibodies. [125I] Protein A was used to measure the bound IgG antibody. Increments of homologous and heterologous fluid-phase ligand completed with solid-phase ligand for antibody and resulted in decreasing amounts of bound [125I]-Protein A. The serologic specificity for each immune system was determined. Immunoassays for thromboxane B2, 6-keto-prostaglandin F1 alpha, and 5,6-dihydro-prostaglandin I2 were used to identify their respective homologous ligands that were separated by normal phase and reversed phase high pressure liquid chromatography.

Studies on PGBx, a polymeric derivative of prostaglandin B1: I. Synthesis and purification of PGBx.

PGBx, a new polymeric derivative of PGB1, previously was shown to (a) restore oxidative phosphorylation to degraded isolated rat liver mitochondria in vitro and (b) to reverse the effects of cardiogenic ischemia in monkeys and cerebral ischemia in rabbits. This report describes in detail the synthesis and purification of PGBx via PGB1, starting with azelaic acid. Details of the in vitro mitochondrial assay are also reported. Purified PGBx exhibiting maximal reactivation of mitochondrial phosphorylation has a mean molecular weight of 2350. Yield of PGBx based on azelaic acid is 4% and based on PGB1 is 25%.