Piperidinohydroxypropyl Sephadex LH-20 Research Articles

High-performance liquid chromatographic-fluorescence determination of human faecal bile acids

A high-performance liquid chromatographic method with fluorescence detection has been developed for the determination of human faecal bile acids, especially free faecal bile acids. Faecal bile acids were extracted using an Amberlite XAD-2 column and then fractionated into four groups (free, glycine-conjugated, taurine-conjugated and sulphated bile acids) on a piperidinohydroxypropyl Sephadex LH-20 column. The free bile acid fraction and free bile acids obtained after enzymatic hydrolysis and/or solvolysis of the three other fractions were derivatized with 1-bromoacetylpyrene and dicyclohexyl-18-crown-6-ether. The derivatized bile acids were separated stepwise on a Shim-pack CLC-ODS column using acetonitrilemethanol-water (100:50:30) (A), (1 00:50:20) (B), and (100:50:0) (C) as mobile phases with changing automatically from A to C using a solvent changer. Calibration curves of bile acid standards were linear in the range between 20 and 400 pmole, when monitored at 370 nm (excitation) and 440 nm (emission). Percent recoveries of bile acids from human faecal samples were between 80 to 95%. The method is applicable to clinical use and is sensitive, reliable, and useful for the detailed determination of human faecal bile acids, especially of free faecal bile acids.

Application of 3 alpha-hydroxysteroid dehydrogenase column to the determination of bile acids fractionated by high-performance liquid chromatography: advantage of pretreating human bile acids with Seppak C18 and piperidinohydroxypropyl Sephadex LH-20.

The analysis of bile acids in human bile was tried by high-performance liquid chromatography (HPLC). Bile acids in human bile were first prefractionated into free, glycine- and taurine-conjugated bile acids using a Seppak C18 cartridge and a piperidinohydroxypropyl Sephadex LH-20 (PHP-LH-20) column. Each fraction was then processed through a HPLC system consisting of a Zorbax ODS column and a 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) column. By these procedures the major 15 bile acids were clearly separated, and each bile acid of 10-125 ng was accurately analyzed. More than 400 times of analysis could be repeated on one 3 alpha-HSD column without loss of sensitivity. Thus the pretreatment through Seppak C18 and PHP-LH-20 made the HPLC analysis of human bile acids accurate and applicable to clinically obtained materials.

Studies on steroids : CCXXVII. Separation and determination of bile acid 7- and 12-sulphates in urine by high-performance liquid chromatography with fluorescence labelling

A method for the characterization and determination of bile acid 7- and 12-sulphates in urine without prior deconjugation is described. The sulphate fraction was obtained from an urine specimen by passing it through a Sep-Pak C 18 cartridge, followed by group separation by ion-exchange chromatography on a lipophilic gel, piperidinohydroxypropyl Sephadex LH-20. Bile acid 7- and 12-sulphates were derivatized quantitatively into the fluorescence compounds through the hydroxyl group at C-3 by treatment with 1-anthroyl nitrile in the presence of quinuclidine in acetonitrile. Subsequent resolution into individual 7- and 12-sulphates was attained by high-performance liquid chromatography (HPLC) on a Cosmosil 5C 18 column using 0.3% potassium phosphate buffer (pH 4.0)-methanol (1:3) as a mobile phase. The 3-(1-anthroyl) derivatives of 7- and 12-sulphates were monitored by fluorescence detection. Taurochenodeoxycholate 7-sulphate in human urine was unequivocally identified on the basis of behaviour in HPLC using mobile phases of different pH values. The present method has proved to be applicable to the characterization and quantification of bile acid 7- and 12-sulphates in human urine.

Determination of Zeranol and Estradiol in Beef by High Performance Liquid Chromatography with Electrochemical Detection

A method for the determination of zeranol and estradiol in beef by high performance liquid chromatography using an electrochemical detector (ECD-HPLC) is described. Zeranol and estradiol in beef were extracted with 80% methanol and re-extracted into dichloromethane. The crude extract was purified by column chromatography on piperidinohydroxypropyl Sephadex LH-20. Zeranol, estradiol and other anabolic drugs were clearly separated on a Shim-pack CLC-ODS column with 0.2% ammonium carbonate-acetonitrile (70:45) without any interference. The quantitation limits of zeranol and estradiol were 600pg and 450pg, respectively. The recovery rates of the two steroids added to beef were 88-97%. The proposed method was applied to the quantitation of zeranol and estradiol in commercial beef.

A enzymatic and fluorimetric determination of total bile acid sulfates in human urine.

A simple, precise and sensitive method for separation and determination of total bile acid sulfates in human urine is described. The sulfate fraction of urinary bile acids was separated with lipophilic anion exchange gel, piperidinohydroxypropyl Sephadex LH-20 after sample clean-up with Sep-Pak C18 cartridge. The obtained sulfate fraction was submitted to solvolysis with a small volume of dimethoxypropane-HCl solution and subjected to enzymatic-fluorimetrical assay using 3 alpha-hydroxysteroid dehydrogenase and resazurin. In this method, no influence of existing salts in the reaction mixture on fluorescence intensity was observed and solvolysis reaction was almost complete. Overall recoveries of glycine- and taurine-conjugated bile acid 3-sulfates from normal urine ranged from 90.5 to 93.7% and those of unconjugates from 48.7 to 78.0%. The sensitivity of the described method enabled to estimate total bile acid sulfates with 0.5 ml of normal urine and precision tests showed the satisfactory accuracy. The level of total urinary bile acid sulfates was estimated on some patients with hepatobiliary diseases and healthy subjects.

Studies on Steroids: CCXVII. Separation and characterization of bile acid 3-glucuronides in human urine by high-performance liquid chromatography

The separation and characterization of unconjugated and conjugated bile acid 3-glucuronides in biological fluids without prior deconjugation by high-performance liquid chromatography (HPLC) are described. A urine sample from a patient with obstructive jaundice was passed through a Sep-Pak C 18 cartridge and was separated into groups by ionexchange chromatography on a lipophilic gel, piperidinohydroxypropyl Sephadex LH-20, providing the glucuronide fraction. Subsequent resolution into individual 3-glucuronides was attained by HPLC on μBondapak C 18 and Shodex ODS Pak F-411 columns. The 3-glucuronides of cholate, deoxycholate, chenodeoxycholate, glycocholate, glycochenodeoxycholate and taurochenodeoxycholate were identified on the basis of their behaviour in HPLC using mobile phases of different pH. The enzymatic hydrolysis of these glucuronides and derivatization of deconjugated bile acids with 1-anthroyl nitrile followed by chromatographic separation on a Cosmosil 5C 18 column with fluorescence detection were carried out for unequivocal characterization. The ratio of unconjugated, glyco- and tauro-conjugated bile acid 3-glucuronides excreted in urine was found to be ca. 2:3:1.

Identification of bile alcohols in urine from healthy humans.

Bile alcohols present in urine from healthy adults were studied. Urine was extracted with octadecylsilane-bonded silica gel, and a neutral fraction and a glucuronide fraction were isolated by ion exchange chromatography on piperidinohydroxypropyl Sephadex LH-20. Following hydrolysis of the glucuronide fraction with beta-glucuronidase and purification by silica gel column chromatography, the bile alcohols were analyzed by a combined gas-liquid chromatography-mass spectrometry. By direct comparison with reference standards, the structures of four major bile alcohols were elucidated as follows: 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25- pentol ; 5 beta-cholestane-3 alpha,7 alpha,12 alpha,24, 25- pentol ; 5 beta-cholestane-3 alpha,7 alpha,12 alpha,25,26- pentol ; and 5 beta-cholestane-3 alpha,7 alpha,12 alpha,26,27- pentol . The daily excretion of these four bile alcohols in urine was 0.5-1.0 mumoles. After purification by silica gel column chromatography, the neutral fraction was analyzed by a combined gas-liquid chromatography-mass spectrometry. The major bile alcohol excreted in urine as the unconjugated form was 27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,25- pentol . The daily excretion of the unconjugated C26 pentol (0.02-0.05 mumoles) was far lower than that of the conjugated C26 pentol (0.34-0.86 mumoles).

Direct measurement of urinary bile acids of infants by high-performance liquid chromatography connected with an enzyme immobilized column.

An accurate and sensitive method by high-performance liquid chromatography connected with 3 alpha-hydroxysteroid dehydrogenase immobilized column for the measurement of urinary bile acids of noncholestatic and cholestatic infants was performed in this study. The purification and group separation of urinary bile acids were done through a piperidinohydroxypropyl Sephadex LH-20 column. By ultraviolet spectromonitor, non 3 alpha-hydroxy bile acids such as 3 beta-hydroxy-5-cholenate were determined, and 3 alpha-hydroxy bile acids by fluorescence spectromonitor. Urinary bile acids in the specimens obtained from noncholestatic and cholestatic infants were determined by this procedure. Major bile acids were cholate, chenodeoxycholate conjugates and cholate unconjugate in healthy infants. In cholestatic infants, total and individual bile acids were extremely increased, and 3 beta-hydroxy-5-cholenate conjugates appeared in the sulfated fraction.

Determination of sulfated and nonsulfated bile acids in serum by mass fragmentography

A Sep-Pak C 18 cartridge was used for purification of bile acids from serum. Three kinds of deuterium labeled internal standards were required for accurate measurement of individual sulfated and nonsulfated bile acids. These internal standards were added to the serum before its application to the cartridge. Separation of sulfated and nonsulfated bile acids was performed on piperidinohydroxypropyl Sephadex LH-20 column chromatography. The nonsulfate fraction was submitted to alkaline hydrolysis, and the sulfate fraction to solvolysis followed by alkaline hydrolysis. Each fraction was converted to the hexafluoroisopropyl-trifluoroacetyl derivatives and quantitated by mass fragmentography. The recovery of each bile acid sulfate was quite satisfactory. In fasting healthy subjects the mean of total nonsulfated bile acids in serum was 1.324 μg/ml, and that of total sulfated bile acids was 0.450 μg/ml. Sulfated lithocholic acid comprised a large part of sulfated bile acids in healthy subjects.

Studies on steroids : CLXXXVII. Determination of serum bile acids by high-performance liquid chromatography with fluorescence labeling

A method for the simultaneous determination of bile acids in serum by high-performance liquid chromatography (HPLC) with fluorescence labeling is described. The bile acid fraction was obtained from a serum specimen by passing it through a BondElut cartridge. Bile acids were derivatized quantitatively into the fluorescent compounds through the hydroxyl group at C-3 by treatment with 1-anthroyl nitrile in the presence of quinuclidine in acetonitrile. These derivatives were separated into the free, glycine- and taurine-conjugate fractions by ion-exchange chromatography on a lipophilic gel, piperidinohydroxypropyl Sephadex LH-20. Subsequent resolution of each fraction into cholate, ursodeoxycholate, chenodeoxycholate, deoxycholate and lithocholate was attained by HPLC on a Cosmosil 5C 18 column using 0.3% potassium phosphate buffer (pH 6.0)—methanol (1:5) and 0.1% potassium phosphate buffer (pH 6.0)—methanol (1:8) as mobile phases. The anthroyl bile acids were monitored by fluorescence detection (excitation wavelength 370 nm; emission wavelength 470 nm), the limit of detection being 20 fmol. The proposed method proved to be applicable to the quantitation of bile acids in serum with satisfactory reliability and sensitivity.

Fluorescence high-performance liquid chromatographic determination of free and conjugated bile acids in serum and bile using 1-bromoacetylpyrene as a pre-labeling reagent

A fluorescence high-performance liquid chromatographic method is described for the determination of free and conjugated bile acids in serum and bile. Free and conjugated bile acids are extracted from serum or bile using a Sep-Pak C 18 cartridge and then fractionated on a piperidinohydroxypropyl Sephadex LH-20 column. Free and glycine-conjugated bile acids are labeled with 1-bromoacetylpyrene in acetonitrile using dicyclohexyl-18-crown-6-ether as catalyst. Taurine-conjugated bile acids are hydrolyzed by cholylglycine hydrolase and then derivatized by the same reagent. Derivatized bile acids are separated stepwise on a reversed-phase column (Radial Pak A) using acetonitrile—methanol—water (A) (100 : 50 : 40) and (B) (100 : 50 : 20) as mobile phase. The eluate is monitored by a fluorophotometer at 370 nm (excitation) and 440 nm (emission). Linearities of fluorescence intensities (peak heights) with the amounts of free and conjugated bile acids were obtained between 50 pmol and 200 pmol for free bile acids and between 25 pmol and 100 pmol for glycine-conjugated bile acids, respectively. Recoveries from serum and bile samples are not less than 90%. This method is sensitive, reliable and useful for the simultaneous determination of free and conjugated bile acids in serum and bile.

Quantitative determination of bile acid glucuronides in serum by mass fragmentography.

Individual non-glucuronidated . non-sulfated, glucuronidated and sulfated bile acids in serum were determined, i.e. lithocholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, and cholic acid, by mass fragmentography. Glucuronic acid conjugates of lithocholic acid, deoxycholic acid, chenodeoxycholic acid, and cholic acid were synthesized via the Koenigs-Knorr condensation reaction. Deuterium labeled deoxycholic acid, lithocholic acid glucuronide, deoxycholic acid glucuronide, and deoxycholic acid sulfate were synthesized and used as internal standards. A serum sample of 1 ml including internal standards was purified with a Sep-Pak C18 cartridge. After the enzymatic cleavage of amino acid conjugates, bile acids were separated into three fractions, free, glucuronidated, and sulfated bile acids, using piperidinohydroxypropyl Sephadex LH-20 (Goto et al. (1978) Clin. Chim. Acta 87). Glucuronidated and sulfated bile acids were deconjugated by beta-glucuronidase treatment and solvolysis. Each fraction was converted to the hexafluoroisopropyl-trifluoroacetyl derivative and quantitated by mass fragmentography. The average concentrations of individual bile acid glucuronides from healthy fasting subjects (n = 9) were as follows; lithocholic acid 0.013 microgram/ml, deoxycholic acid 0.083 microgram/ml, chenodeoxycholic acid 0.078 microgram/ml, ursodeoxycholic acid 0.013 microgram/ml, and cholic acid 0.007 microgram/ml. Bile acid glucuronides occupied 7.8% of the total bile acids.

Foetomaternal relationships of serum bile acid pattern estimated by high-pressure liquid chromatography.

The bile acid patterns in the maternal and umbilical vein and artery serum samples were analysed by a two-step chromatographic method involving group separation by piperidinohydroxypropyl-Sephadex LH-20 and high-pressure liquid chromatography using immobilized 3 alpha-hydroxy steroid dehydrogenase. Glycochenodeoxycholate predominates in the maternal blood and taurochenodeoxycholate in the umbilical blood. In cases where a free bile acid was detected in the maternal blood, the same bile acid was also demonstrated in the corresponding cord blood. The concentrations of taurocholate and taurochenodeoxycholate were found to be significantly higher in the umbilical artery than in the corresponding umbilical vein. Our data suggest that there is a bidirectional placental transfer of free bile acids and that there is a transfer of taurine-conjugated primary bile acids from the foetus to the mother.

Assay of free and glycine- and taurine-conjugated bile acids in serum by high-pressure liquid chromatography by using post-column reaction after group separation.

An accurate and sensitive method that involves the group separations of serum bile acids (i.e. free and glycine- and taurine-conjugated bile acid fractions) by ion-exchange chromatography on piperidinohydroxypropyl-Sephadex LH-20 is described. Each group was then analysed by high-pressure liquid chromatography by using the post-column reaction technique with immobilized 3 alpha-hydroxy steroid dehydrogenase. The bile acid patterns in the umbilical venous serum samples were analysed by this method. Taurochenodeoxycholate predominated in the umbilical blood.

Studies on steroids : CLXX. Separation and determination of bile acid 3-sulfates in human bile by high-performance liquid chromatography

A method for the simultaneous determination of sulfated bile acids in human bile without prior hydrolysis and solvolysis is described. The sulfate fraction was obtained from a bile specimen by passing it through a Sep-Pak C 18 cartridge, followed by group separation by ion-exchange chromatography on a lipophilic gel, piperidinohydroxypropyl Sephadex LH-20. Subsequent resolution into the 3-sulfates of unconjugated, glycine- and taurine-conjugated ursodeoxycholate, cholate, chenodeoxycholate, deoxycholate and lithocholate was attained by high-performance liquid chromatography (HPLC) on an SC-02 column. Separation of these sulfates was effected when acetonitrile—0.5% ammonium carbonate (8:31, 8:26 and 8:23, v/v) was used as mobile phase. The sulfated bile acids in human bile were unequivocally identified on the basis of their behaviour in HPLC using mobile phases of various pH values. The present method proved to be applicable to the characterization and quantitation of sulfated bile acids in human bile.

Simultaneous determination of biliary bile acids in rat: ELectron impact and ammonia chemical ionization mass spectrometric analyses of bile acids

Bile acids in the rat bile were fractionated into unconjugated, glycine- and taurine-conjugated fractions by employing piperidino-hydroxypropyl Sephadex LH-20 ion-exchange chromatography. Subsequently, these fractions were analyzed by gas-liquid chromatography (GLC) and GLC-mass spectrometry using a Silicone AN-600 column. Not only lithocholic acid, deoxycholic acid, chenodeoxycholic acid, hyodeoxycholic acid, ursodeoxycholic acid and cholic acid, but also αand β-muricholic acids were quantitatively and simultaneously detectable in conjugated and unconjugated fractions, respectively. In the unconjugated and conjugated fractions, varying amounts of the unidentified bile acid were detected upon GLC. The electron impact and ammonia chemical ionization mass spectrometric results and catalytic hydrogenation on the compound indicate that this bile acid seems to be a derivative of β-muricholic acid having a double bond in the side chain. The present method is suitable to the simultaneous and quantitative determination of unconjugated and glycine- and taurine-conjugated bile acids in the rat bile.