Synthesis of corticosteroid haptens

Sterol peroxidation by Pseudomonas fluorescens cholesterol oxidase

Cholesterol is oxidized by commercially available Pseudomonas fluorescens cholesterol oxidase to 6 beta-hydroperoxycholest-4-en-3-one as the initial product, with none of the expected produce, cholest-4-en-3-one, formed. The transformation indicates that P. fluorescens cholesterol oxidase also acts as a flavoprotein dioxygenase.

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors: oxime ether analogs of pravastatin

Pravastatin, a potent anti-hypercholesteremic drug, has been developed by Bristol-Myers Squibb for treatment of hypercholesterolemia and other related diseases. Several structurally related compounds (SQ 31,554, SQ 31,879, SQ 31,947, SQ 32,391, SQ 32,770, SQ 32,390 and SQ 32,469) modified at the 3-position of the hexahydronaphthalene ring system of pravastatin were prepared in the course of developing the basic reagents for a radioimmunoassay of the parent drug. The biological activity of these analogs was comparable to pravastatin itself. Indeed, one member of this series was found to be several times more potent than pravastatin.

Synthesis and characterization of the 6 alpha- and 6 beta-hydroxylated derivatives of corticosterone, 11-dehydrocorticosterone, and 11-deoxycortisol

This report describes the synthesis of 6 alpha, 17,21- and 6 beta, 17,21-trihydroxypregn-4-ene-3,20-dione, 6 alpha, 7,21- and 6 beta, 11 beta, 21-trihydroxypregn-4-ene-3,20-dione, and--for the first time--that of 6 alpha, 21- and 6 beta, 21-dihydroxypregn-4-ene-3,11,20-trione. The former four compounds were prepared by 6-hydroxylation of 17,21-trihydroxypregn-4-ene-3,20-dione and 11 beta, 21-dihydroxypregn-4-ene-3,20-dione, respectively. This was achieved by autoxidation or by oxidation with 3-chloroperbenzoic acid, of the 3-methoxy-pregna-3,5-dienes of the latter two steroids. The yield of the 6 beta-hydroxylated steroids, but not of their corresponding 6 alpha-epimers, was higher using autoxidation than the peracid. The two 6-hydroxylated pregnenetriones were prepared from 6 alpha, 21-diacetoxy-11 beta-hydroxypregn-4-ene-3,20-dione and 6 beta, 21-diacetoxy-11 beta-hydroxypregn-4-ene-3,20-dione, respectively, by oxidation with pyridinium chlorochromate. The above-mentioned six steroids were identified and characterized by nuclear magnetic resonance, infrared, ultraviolet, high performance liquid chromatography, gas chromatography, and mass spectrometry.

Preparation of europium-labeled derivatives of cortisol for time-resolved fluoroimmunoassays

Cortisol 3-(O-carboxymethyl)oxime, 6- and 21-hemisuccinoxycortisol, and cortisol 7-carboxyethyl thio-ether were synthesized. These carboxyl derivatives were labeled using a described general labeling method with a europium chelate. The labeled steroids were tested in a competitive time-resolved fluoroimmunoassay using antibodies raised against cortisol. Only the site-homologous antigen-antibody pairs underwent immunoreaction and gave satisfactory calibration curves.

Radioimmunoassay of plasma 21-deoxycortisol

A reliable radioimmunoassay for the determination of plasma 21-deoxycortisol (21-DF) after chromatography on Sephadex LH20 columns of methylene chloride plasma extracts has been described and evaluated. The antiserum used was raised in rabbits injected with 21-DF-3-(O-carboxy-methyl)oxime-bovine serum albumin. In men (n = 10) the levels ranged from 0.11 to 0.29 ng/ml (mean +/- SD: 0.21 +/- 0.06). In women the mean levels were in the follicular phase: 0.16 +/- 0.06 (range: 0.05-0.22; n = 10) and in the luteal phase: 0.18 +/- 0.06 (range: 0.10-0.35; n = 12). No cyclical change and no significant difference between male and female groups were observed. In patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency very high levels were observed. The higher concentration of 21-DF found in adrenal effluent than in peripheral plasma has provided direct evidence of its adrenal origin in patients without 21-hydroxylase deficiency.

ELISA of 6-beta-hydroxycortisol in human urine: diurnal variations and effects of antiepileptic therapy

An enzyme-linked immunosorbent assay for urinary 6-beta-hydroxycortisol (6-beta-OHF) was developed. A highly specific antiserum against 6-beta-OHF-21-hemisuccinate bovine serum albumin (6-beta-OHF-21-HS-BSA) raised in rabbit was used. The enzyme-labelled hapten was prepared by the mixed anhydride method using horse radish peroxidase (HRP). The limit of detection is very low (10 pg), the intra-assay variation ranges from 5.2-6.6%, the inter-assay variation is 8.2-8.3%. Cross reactivities of various steroids are very low. The diurnal variations in urinary 6-beta-OHF and it's ratio to 17-hydroxycorticosteroids (17-OHCS) were studied in six healthy volunteers. No significant difference was found within the 24 h for the ratio of 6-beta-OHF to 17-OHCS. A large increase of 8-12 h urinary 6-beta-OHF was observed in patients receiving chronic treatment with antiepileptics.

Chemiluminescence enzyme immunoassay of dehydroepiandrosterone and its sulfate using peroxidase as label

We report a highly sensitive enzyme immunoassay for dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S) using horseradish peroxidase as the label enzyme. Separation of free and bound DHEA-peroxidase conjugate was by insolubilized antibody, prepared by coupling purified IgG of goat anti-rabbit IgG serum with Sepharose 4B or a polystyrene tube. The enzyme activity was measured by the chemiluminescence reaction using luminol and hydrogen peroxide as substrate. The faint chemiluminescence was measured by a photon counter. The sensitivity was 25 pg/assay tube for DHEA and 100 pg/assay tube for DHEA-S. Upon comparison, results obtained by radioimmunoassay and this method showed good agreement ; r = 0.86 for free DHEA, r = 0.92 for acid-hydrolyzed DHEA-S and r = 0.91 for solvolyzed DHEA-S. The present method is applicable in the routine determination of DHEA and DHEA-S in biological fluid.

Preparation of dehydroepiandrosterone, testosterone and progesterone antigens through 7-carboxymethyl derivatives: characteristics of the antisera to testosterone and progesterone

Dehydroepiandrosterone, testosterone and progesterone 7-carboxymethyl derivatives were prepared: 7 alpha and 7 beta epimers were separated and coupled to bovine serum albumin. Preliminary studies of the antisera induced by these antigens showed that they have high affinity and good specificity.

Use of sodium salicylate as a blocking agent for cortisol-binding-globulin in a radioimmunoassay for cortisol on unextracted plasma

This report describes investigations into the use of sodium salicylate as a cortisol-binding-globulin blocking agent and the subsequent development of a radioimmunoassay for cortisol on unextracted plasma. Cortisol antiserum was raised against a cortisol 3-O-(carboxy-methyl) oxime-bovine serum albumin conjugate. A 125I-labelled cortisol-tyrosine methyl ester conjugate was also prepared for use in the assay. The radioimmunoassay developed involved no pre-treatment of extraction of the samples before analysis and was extremely simple to perform. Comparison with another radioimmunoassay for cortisol and with the Mattingly fluorimetric assay gave good correlation.

An improved synthesis of 6beta-hydroxy-5beta-pregnane-3,20-dione

6beta-Hydroxy-5beta-pregnane-3,20-dione, formerly prepared by hydroboration method, has been obtained in greatly improved yield by a simpler irradiation-hydrogenation procedure.

Radioimmunoassay of 6beta-hydroxycortisol in human plasma and urine

A sensitive and reliable radioimmunoassay for urine and plasma 6beta-hydroxycortisol has been developed. Antiserum showing high specificity against 6beta-hydroxycortisol was produced in rabbits immunized with 6beta-hydroxycortisol 21-hemisuccinate-bovine serum albumin. The sensitivity of the assay was 25 pg on a diluted sample equivalent to 1 microliter of urine, and on 50 microliter of plasma after separation by celite chromatography. The intra- and inter-assay coefficients of variation for urine were 4.8 and 6.7% and those for plasma were 4.2 and 12.1%. Concentrations were determined in patients with bronchogenic carcinoma, in patients treated with dilantin, in neonates, and in infants aged 5-12 months.