An HPLC method for the determination of the free cortisol/cortisone ratio in human urine

The measurement of the urinary free cortisol-cortisone ratio has been reported to be a sensitive indicator of renal 11 beta-hydroxysteroid dehydrogenase type 2 (11 beta-HSD 2) activity. This converts biologically active cortisol to inactive cortisone. A decrease in its activity (e.g. through disease or inhibition caused by a therapeutic agent or a foodstuff) may increase cortisol levels and susceptibility towards hypertension. The method presented here uses a simple isocratic tandem column HPLC system. The method has been validated and found to be robust and reproducible. The lower limit of quantification (LLOQ) was found to be 10 ng/mL for both cortisol and cortisone. Samples of urine (n = 99) from patients, most of whom were on complex combinations of drugs, were analyzed and 92% of samples were found to give successful results with this method (cortisol and cortisone above LLOQ). The ratio ranged from 0.07 to 5.61. No interferences were noted from the drugs that the patients were taking. It was also found that a morning spot urine sample gave comparable results to 24 h collection samples, thus making sample collection much easier.     

高效液相色谱法测定磷酸苯丙哌林片的含量

 采用反相高效液相色谱法 ,以醋酸可的松为内标 ,测定磷酸苯丙哌林片的含量。色谱柱为ODS柱 ,以甲醇 水 冰醋酸 三乙胺溶液 (体积比为 6 0∶35∶5∶0 1)为流动相 ,检测波长为 2 70nm ,磷酸苯丙哌林在 9 96mg/L～ 49 8mg/L范围内有很好的线性关系 (r=0 9998) ,平均回收率为 99 91% (n =5 ) ,RSD =0 43%。     

Thin-Layer Chromatographic Competitive Protein-Binding Assay for Cortisol and Cortisone, and its Application to Urine Samples from Healthy Men Undergoing Water Diuresis

Specific and rapid determination of free cortisol (compound F) and cortisone (compound E) in human urine has been achieved by concentration of the urine samples, liquid–liquid extraction of the concentrated samples, thin-layer chromatography of ethanolic extracts on aluminium foil-backed silica gel 60 TLC plates, location of the steroids under UV light, elution of cortisol and cortisone from sections of the plates with phosphate buffer, and measurement by competitive protein-binding assay. Chicken serum was used as the source of corticosteroid binding globulin, because it binds cortisol and cortisone with similar high affinity. The method combining thin-layer chromatography and competitive protein-binding assay is easy to perform, specific, sensitive, and quite rapid. Free cortisol and cortisone were measured in the urine of male individuals who abstained from water intake for 2 h or who ingested 1 L of water. The results show, for the first time, that short-term water diuresis markedly increases urinary free cortisone excretion, supporting our previous hypothesis that its excretion is positively correlated with urine volume, i.e. with the volume of 24-h urine samples.     

Micro determination of cortisol and cortisone in umbilical cord blood by chemiluminescent high‐performance liquid chromatography

A simple, sensitive and specific chemiluminescent high‐performance liquid chromatography method, based on the luminol reaction, for determination of serum cortisol and cortisone, was established. In infants, placental 11β‐hydroxysteroid dehydrogenase type 2 enzyme (11β‐HSD2) activity may affect adrenal function early after birth. The cortisol–cortisone ratio of serum concentrations in umbilical cord blood is an indicator of placental 11β‐HSD2 activity. The optimum conditions for the luminol reaction were determined to be 1.5 mM luminol, 0.6 M sodium hydroxide, 0.15 mm potassium hexacyanoferrate(III) and 200 mM potassium hexacyanoferrate (II). The calibration curves for cortisol and cortisone exhibited good linearity. The correlation coefficients of the calibration curves were 0.996. The intra‐ and inter‐day precisions were in the ranges: cortisol 7.0–12.2 and 4.4–9.2%, cortisone 5.3–7.0 and 6.2–9.9%. The recoveries of these steroids were in the ranges: cortisol 97–105%, cortisone 94–102%. The limits of detection were as follows: cortisol, 0.17 μg/dl; cortisone 0.15 μg/dl. This assay could be successfully applied to determination of the cortisol–cortiosone ratio of serum concentrations in umbilical cord bloods. Copyright © 2009 John Wiley & Sons, Ltd.     

Biotransformation of Cortisone with Rhodococcus rhodnii: Synthesis of New Steroids

Cortisone is a steroid widely used as an anti-inflammatory drug able to suppress the immune system, thus reducing inflammation and attendant pain and swelling at the site of an injury. Due to its numerous side effects, especially in prolonged and high-dose therapies, the development of the pharmaceutical industry is currently aimed at finding new compounds with similar activities but with minor or no side effects. Biotransformations are an important methodology towards more sustainable industrial processes, according to the principles of “green chemistry”. In this work, the biotransformation of cortisone with Rhodococcus rhodnii DSM 43960 to give two new steroids, i.e., 1,9β,17,21-tetrahydoxy-4-methyl-19-nor-9β-pregna-1,3,5(10)-trien-11,20-dione and 1,9β,17,20β,21-pentahydoxy-4-methyl-19-nor-9β-pregna-1,3,5(10)-trien-11-one, is reported. These new steroids have been fully characterized.     

多羰基甾体化合物的区域和立体选择性还原

在对多羰基甾体化合物雄甾-4-烯-3,6,17-三酮及可的松的还原研究中发现,在不同金属离子如Ce3+、Mn2+、Co2+ 及Ni2+存在下,以甲醇为溶剂,NaBH4为还原剂对上述这两个多羰基甾体化合物进行还原,可以得到不同的区域和立体选择性还原产物.     

Simultaneous Determination of Free Cortisol,Cortisone and their Tetrahydrometabolites in Urine by Single Solvent Extraction and Liquid Chromatography–Tandem Mass Spectrometry

Abstract

A fast, efficient and low-cost high performance liquid chromatography–tandem mass spectrometry methodology was developed and validated for the simultaneous determination of free urinary cortisone, cortisol and their tetrahydro-metabolites. The developed method comprises a simple liquid-liquid extraction with CH₂Cl_2, followed by reversed-phase liquid chromatography–tandem mass spectrometry (LC–MS/MS) with electrospray ionization (ESI) in positive mode. The baseline chromatographic separation of the analytes, including the stereoisomers tetrahydrocortisol (THF) and allo-THF, was achieved on a Hypersil Gold C₁₈ column with a mobile phase consisting of 0.05%v/v formic acid in water—acetonitrile, using a gradient elution program. The influence of the mobile phase composition and the ESI parameters on the sensitivity of the method was extensively studied. Sample preparation was also optimized, testing two techniques: solid phase extraction (SPE) and liquid-liquid extraction (LLE). Recoveries ranged from 74.7% (a-THF) to 93.5% (cortisol) and the method limits of detection (MLD) ranged from 0.34?ng mL^?1 (cortisol) to 1.37?ng mL^?1 (THF). Intra- and inter-day coefficient of variation of the assay varied from1.5% (allo-THF) to 13% (tetrahydrocortisone) and from 3.6% (allo-THF) to 14.9% (tetrahydrocortisone), respectively. The method was applied for the analysis of urine samples from 53 healthy individuals with a mean age of 13.96?years in order to estimate the concentration of the five corticosteroids and the ratio of the metabolites. Associations between urinary cortisol/cortisone and serum cortisol/cortisone values were also characterized.