High-performance liquid chromatography of p-nitrophenacyl esters of selected prostaglandins on silver ion- loaded microparticulate cation-exchange resin

Sex pheromone components of fall cankerworm moth,Alsophila pometaria : Synthesis and field trapping

(Z,Z,Z,E)-3,6,9,11-Nonadecatetraene and (Z,Z,Z,Z)-3,6,9,11-nonadecatetraene, sex pheromone components ofAlsophila pometaria, were synthesized by stereoselective Wittig reactions and found to be spectroscopically and chromatographically identical to isolated natural material. Flight-tunnel bioassays and field-trapping experiments confirmed that the two tetraenes together with (Z,Z,Z)-3,6,9-nonadecatriene are sex pheromone components. While traps baited with either tetraene individually captured conspecific males in field-trapping experiments, addition of the triene, which captured no males by itself, to either tetraene resulted in synergistic responses.

High-performance liquid chromatographic determination of cortolic and cortolonic acids as pyrenyl ester derivatives

A new procedure is described for the detection of the acidic metabolites of cortisol (cortoic acids) as the pyrenylmethyl-21-oic esters. The derivatizing reagent, diazomethylpyrene, was prepared by an improved procedure. The reagent was used at room temperature, required no catalyst, and was not restricted by stoichiometric requirements. The steroid esters were separated by reversed-phase high-performance liquid chromatography and analyzed simultaneously by their ultraviolet absorbance and fluorescence characteristics. Identities of the products were confirmed using the photodiode array detector to determine spectral profiles, absorbance maxima, and absorbance ratios. Further confirmation of identity of the cortoic acid esters used mass spectrometry under normal and collision-activated dissociation conditions. With the method described, a linear spectral response was obtained between 8 and 1680 fmol. Application of the technique to the analysis of steroid acids in human urine indicated the presence of cortoic acids.

Identification of reaction products from the pyridinium dichromate derivatization of prostaglandins by high-performance liquid chromatography and direct chemical ionization mass spectrometry

The reaction products from the oxidation of prostaglandins with pyridinium dichromate have been identified by direct chemical ionization mass spectrometry of the underivatized compounds after separation by reversed-phase high-performance liquid chromatography and ultraviolet diode-array detection. The thermal influence on the reproducibility of the dehydration patterns of the mass spectra was studied. The main products from the prostaglandins E1, E2, F1 alpha and F2 alpha were the corresponding 15-oxo derivatives. Minor amounts of the 9,11,15-trioxoprostaglandin were formed from PGE, while the oxidation of PGF was less selective, yielding additional dioxo derivatives. Addition of water to the reagent reduced the reactivity, but increased the selectivity in favour of the formation of 15-oxo-PGF during the oxidation of PGF.

Fluorimetric high-performance liquid chromatography of prostaglandins and its application to their determination in human seminal fluid

A highly sensitive and simple high-performance liquid chromatographic method with fluorescence detection for the determination of prostaglandins is described. Prostaglandins are converted into the corresponding fluorescent derivatives by reaction with 3-bromomethyl-6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone in the presence of potassium hydrogen carbonate and 18-crown-6 in acetonitrile. The derivatives are separated simultaneously within 34 min (the total run time per injection, 56 min) on a reversed-phase column (YMC Pack C8) by a stepwise elution with mixtures of acetonitrile, methanol and water and detected fluorimetrically. The detection limits are 10-15 fmol at a signal-to-noise ratio of 5 in a 10-microliter injection volume. Prostaglandins E1, E2, F1 alpha and F2 alpha in human seminal fluids are measured by this method.

Separation and quantification of prostaglandins E1 and E2 as their panacyl derivatives using reverse phase high pressure liquid chromatography

Separation and quantification of prostaglandin E1 (PGE1) and prostaglandin E2 (PGE2) were achieved using reverse phase high performance liquid chromatography (HPLC). Panacyl bromide (p-(9-anthroyloxy)phenacyl bromide) (PAB) derivatives of PGE2 and PGE1 were prepared. Reverse phase HPLC using a linear gradient of 56% to 80% acetonitrile in water containing 0.10% acetic acid gave baseline resolution of the two derivatives. A 3 um diameter particle, C18 column provided good resolution and reproducible recoveries. Human synovial tissue cells were incubated with the precursor fatty acids for PGE1 or PGE2 and stimulated with a crude Interleukin 1 (IL-1) preparation. Cells grown in the presence of dihomogammalinolenic acid (DGLA), the precursor for PGE1, made significantly more PGE1 than cells grown in control medium or in the presence of arachidonic acid, precursor for PGE2. PGE2 synthesis was reduced when DGLA was added to cells (resting or IL-1-stimulated).

High-performance liquid chromatography method for the separation of isomers of 9 beta-methylcarbacyclin (ciprostene) and the analysis of pharmaceutical samples

An high-performance liquid chromatography method was developed that separates (5Z)-9 beta-methyl-6 alpha-carbaprostaglandin I2 (9 beta-methylcarbacyclin; ciprostene) from several closely related isomers: (i) a double bond isomer at C-5, (ii) an epimer at C-15, and (iii) combinations of i and ii. The method uses a Zorbax ODS column with a mobile phase consisting of acetonitrile-buffer pH 2.5 at a ratio of 45:55 for determination of purity and 40:60 for optimum separation of isomers. Detection is measurement of absorbance at 200 nm. Peak heights are measured relative to butylparaben which is used as an internal standard. The method is linear, free from interferences from degradation of ciprostene and has a relative standard deviation of 0.5-1% for solutions at 60 micrograms/ml. This assay has been applied to bulk powders and solutions of the drug. Stressed chemical stability studies have shown that the C-15 allylic secondary alcohol group undergoes epimerization under acidic conditions in solution and oxidation in the solid and solution state under thermal stress or in the presence of oxidants.

Quantitative determination of prostaglandins A1 and B1 in alprostadil (PGE1) by high-performance liquid chromatography

An absorption high-performance liquid chromatography assay for the quantitative determination of prostaglandins A1 and B1 in alprostadil (prostaglandin E1) and in Prostin VR Pediatric Sterile Solution was developed. Prostaglandins A1 and B1 have been shown to be the major degradation products of prostaglandin E1. The adsorption system provided baseline resolution of the 2-naphthacyl esters of prostaglandin A1 from prostaglandin B1. Derivatization conditions providing maximal response for prostaglandins A1 and B1 while minimizing the conversion of prostaglandin E1 to prostaglandins A1 and B1 were established.

Separation of unlabeled metabolites of arachidonic acid from their deuterium- and tritium-labeled analogs by argentation high-pressure liquid chromatography

Deuterium- and tritium-labeled analogs of high isotopic purity are required for the analysis of metabolites of arachidonic acid (20:4) by mass spectrometry and radioimmunoassay. We prepared a number of 2H-labeled standards by incubating [5,6,8,9,11,12,14,15-2H]20:4 with soybean lipoxygenase, polymorphonuclear leukocytes, or homogenates of rat spleen or bovine lung. The unlabeled and 2H-labeled forms of the following products were completely resolved by argentation high-pressure liquid chromatography: 20:4; 5-hydroxy-6,8,11,14-eicosatetraenoic acid (5h-20:4); 11h-20:4; 12h-20:4; 15h-20:4; 12-hydroxy-5,8,10-heptadecatrienoic acid; leukotriene B4; prostaglandin D2 (PGD2); and PGF2 alpha. The corresponding forms of PGE2 and thromboxane B2 were also separated, but not quite as well as the above compounds. Analysis by mass spectrometry indicated that the amounts of unlabeled material in approx 1:1 mixtures of unlabeled and 2H-labeled products could be reduced to 0.1% or less after two steps of argentation high-performance liquid chromatography. Metabolites of 20:4 labeled with tritium were also separated from their unlabeled counterparts and had retention times longer than those of the corresponding 2H-labeled analogs.

Characterization of monohydroxylated lipoxygenase metabolites of arachidonic and linoleic acid in rabbit peritoneal tissue

Rabbit peritoneal tissue contains a lipoxygenase which converts arachidonic acid preferentially into 15-hydroxy-5,8,11,13-eicosatetraenoic acid. Stereochemical analysis of the menthyloxycarbonyl derivative of this metabolite by means of a high-pressure liquid chromatography method, involving the use of a Ag+ -loaded cation-exchange column, indicated that it has mainly the 15-Ls-hydroxy configuration. The biosynthesis of 15-hydroxy-5,8,11,13-eicosatetraenoic acid could be confirmed during examination of the monohydroxy acids obtained without addition of fatty acids, thus formed from endogenously released substrate. However, the 9-and 13-hydroxy derivatives of linoleic acid were also formed and in quantities exceeding those of 15-hydroxy-5,8,11,13-eicosatetraenoic acid.

Sensitive high-performance liquid chromatographic method for prostaglandins using a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin

High-performance liquid chromatography of prostaglandins is developed in which a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin is used to perform the high-sensitivity detection. The reagent reacts with prostaglandins and related compounds to form the ester derivatives, which are separated using a reversed-phase system. Each labeled compound eluted from the column is successively hydrolyzed to the fluorescent coumarin derivative, and this fluorophore is introduced into a flow-through fluorometer. Prostaglandins can be determined in the range of at least 1 nmol to 5 pmol, and the detection limit is about 10 fmol. This system is applied to the analysis of prostaglandins in human seminal fluid.

High performance liquid chromatography and UV detection for the separation and quantitation of prostaglandins

A fast and reliable method for the separation and quantitation of arachidonic acid metabolites PGF1 alpha, PGF2 alpha, PGD2, PGE1, PGE2, PGB2, PGA2, 6-keto PGE1, 6-keto PGF1 alpha, TxB2 and 15-keto PGE2 by high-performance liquid chromatography has been developed. Utilizing a single reverse-phase column and a UV spectrophotometer, sensitivity as little as 30 nanograms of each of these prostaglandins can be separated and subsequently detected. Although this study was performed using standards, it is highly promising for future application to biological fluids.

Complete separation by high performance liquid chromatography of metabolites of arachidonic acid from incubation with human and rabbit platelets

Separation of all major cyclooxygenase and lipoxygenase metabolites of arachidonic acid were obtained by high performance liquid chromatography (HPLC). A C18 reverse-phase column was used in ion suppression mode to separate underivatized metabolites of arachidonic acid isolated from human and rabbit platelets. The metabolites were monitored by measuring radioactivity or ultraviolet light absorption at 192 nm (absorption by double bonds). Comparisons of TLC and HPLC separations demonstrated that the HPLC separation of metabolites of [1-14C]arachidonic acid was quantitative. HPLC also resolved several metabolites that were not detected by scanning of TLC separations.