High-performance liquid chromatographic analysis of demethylmenaquinone and menaquinone mixtures from bacteria

Demethylmenaquinone and menaquinone mixtures from some species of enterobacteria were analysed by reverse-phase partition high-performance liquid chromatography. This method allowed clear separation and quantitative determination of these quinone components.     

High-performance liquid chromatographic analysis of corticosteroids

This review presents recent developments in high-performance liquid chromatographic (HPLC) analysis of corticosteroids for the determination of clinically important steroids in biological specimens. Various sample preparation techniques are described.     

High-performance liquid chromatographic analysis of ubiquinones from new Legionella species

Abstract The ubiquinone composition of Legionella feeleii, L. oakridgensis, L. rubrilucens, L. sainthelensi, L. wadsworthii and some environmental legionella isolates was investigated by high performance liquid chromatography. The results of the present study indicate ubiquinones are valuable criteria for the rapid identification of Legionella species and the recognition of new taxa.     

High-performance liquid chromatographic analysis of oligodeoxyribonucleotide base composition

A significantly improved method for base composition analysis of synthetic oligodeoxyribonucleotides is presented. This highly accurate and sensitive method used enzymatic digestion followed by high-resolution HPLC of the nucleosides to determine the empirical base composition of the parent compound. The enzymatic digestion reaction is quantitative and is not blocked by modified bases, thus allowing the degree of base deprotection and chemical modification to be assessed. Digestion data are presented for oligodeoxyribonucleotides which range from 18 to 150 bases in length with excellent agreement of experimental and theoretical composition. The method is also applicable to high-molecular-weight genomic DNA.     

High-performance liquid chromatographic analysis of radiolabeled inositol phosphates

Separation of inositol phosphates by low-pressure anion-exchange chromatography yields unsatisfactory results, while previously described anion-exchange HPLC methods require such extensive processing times that they preclude efficient sample analysis. Using a low-capacity Vydac nucleotide anion-exchange column, we have developed a method which allows complete separation of myo-inositol, inositol 1-phosphate, inositol 1,4-bisphosphate, inositol 1,4,5-trisphosphate, and inositol 1,3,4,5-tetrakisphosphate in approximately 10 min followed by a 5-min column regeneration time. This method provided exceptional reproducibility and quantitative recovery of each inositol phosphate. One column was used for over 300 separations with no loss in performance or alteration in elution pattern. A modified procedure with a 14-min gradient was developed to separate the 1,3,4- and 1,4,5-isomers of inositol trisphosphate. These separation procedures were used to characterize the kinetics of degradation of inositol phosphates by lysates of erythrocytes and neutrophils. We conclude that these procedures are applicable for rapid and quantitative analysis of radiolabeled inositol phosphates in cellular extracts.     

High-performance liquid chromatographic analysis of glycoamines in serum

This report describes the development of an HPLC-UV method for studies of glycoamines and glycoamine-like compounds in normal human serum and osteosarcoma patient serum as potential biological markers of cancer. The glycoamines, a newly recognized class of endogenous, low-molecular-mass biopolymers, are conjugates of amino acids and sugar units, containing 5 to 29 amino acid and 1 to 17 sugar units. After ultrafiltration of serum samples, reversed-phase HPLC separation with diode-array detection was used to obtain standard profiles of serum ultrafiltrates below M_r 10 000 in healthy subjects. These highly reproducible profiles utilized two-dimensional peak identification and were used to develop a statistical profile of the major glycoamine peaks in normal serum. This newly developed analytical method was subsequently used to address a key question: whether or not there is a single tumor-specific glycoamine or a family of tumor-specific glycoamines in cancer patient serum. Preliminary results suggest that this method can separate and detect glycoamines and glycoamine-like compounds in various types of cancer patient serum with a high degree of reproducibility on the basis of comparative two-dimensional identification of natural compounds and a panel of synthetic glycoamine analogs. Moreover, the method is useful for following the relative changes in the amount of a given glycoamine over an extended clinical time course. Initial results suggest that a glycoamine or glycoamine-like compound, GA-4.63, may have clinical utility in human osteosarcoma studies.     

High-performance liquid chromatographic analysis and separation of N-feruloylserotonin isomers

The N-feruloylserotonin containing fraction was isolated from seeds of Leuzea carthamoides (Willd.) DC by solvent extraction followed by column chromatography on silica gel or on Sephadex LH-20. Nuclear magnetic resonance spectroscopic analysis of the isolated fraction showed the presence of four structurally related compounds. These compounds were identified as four isomers of N-feruloylserotonin: N-(Z)-feruloylserotonin, N-(Z)-isoferuloylserotonin, N-(E)-feruloylserotonin and N-(E)-isoferuloylserotonin. They were analyzed by HPLC on Separon SGX C18, Separon SGX and Separon SGX phenyl, using various mobile phases. Separon SGX phenyl phase was found the most efficient for a rapid analysis and for the final separation of the N-feruloylserotonin isomers.     

High-performance liquid chromatographic analysis of phlorotannins from the brown alga Fucus vesiculosus

Separating individual compounds by HPLC represents an effective method for the detection and quantification of phenolic compounds and has been widely utilised. However, phlorotannins are commonly quantified using colorimetric methods, as the total amount of the whole compound group. In the present paper the separation of a set of individual soluble phlorotannins from the phenolic crude extract of Fucus vesiculosus was achieved by HPLC with UV photodiode array detection. Different gradient programs for reversed- and normal-phase HPLC methods were developed and tested. Normal-phase (NP) conditions with a silica stationary phase and a mobile phase with a linear gradient of increasing polarity were found to separate 16 individual components of the phenolic extract. The suitability of the NP-HPLC method for mass spectrometric application was preliminarily tested. Sample preparation was found to be a critical step in the analysis owing to the rapid oxidation of phlorotannins; ascorbic acid was used as an antioxidant.     

High-performance liquid chromatographic analysis of nitroxoline in plasma and urine

A high-performance liquid chromatographic method has been developed for the determination of nitroxoline in 50-μl plasma and urine samples.A structural analogue of nitroxoline, 8-hydroxyquinoline, was added to the eluent in order to suppress peak asymmetry. Several parameters of the eluent were studied for the optimisation of the chromatographic system.Plasma concentration—time curves were constructed for three volunteers after they had received an oral dose of 100 mg of nitroxoline. Plasma half-life was about 1 h. Within 12 h, about 1% of the dose was excreted in the urine as free nitroxoline and about 30% as conjugated metabolite of the parent compound.     

High-performance liquid chromatographic analysis of ammonium in human urine

A method for the quantitative determination of ammonium in human urine by high-performance liquid chromatography (HPLC) is described. After making fluorescent substances with fluorescamine, they were separated and quantified by their fluorometric intensity. The intensity (as measured by peak height) was linear between 0.5 and 5.0 micrograms, and coefficients of variation for elution time and peak height on replicate analysis of the standard were 0.15 and 4.2%, respectively. Recoveries of added ammonium were 96.5 and 97.3%, respectively, on 2.0 and 3.0 micrograms by this method. Detection limit of this method was 0.2 microgram. There was good agreement between the proposed HPLC method (X) and ion chromatographic method (Y), giving the relationships as Y = 0.956X + 0.012, r = 0.991.     

High-performance liquid chromatographic analysis of fucoganglioside hydrolysis by alpha-L-fucosidase

A sensitive HPLC method has been developed for monitoring fucoganglioside hydrolysis by purified alpha-L-fucosidase. The high-resolution method employs a Lichrosorb-NH2 column, a 10-min isocratic elution with potassium phosphate/acetonitrile buffer, detection of ganglioside products with a uv monitor at 195 nm, and quantification of low picomolar amounts of these gangliosides with an integrator. The usefulness of the HPLC method has been exemplified by using it to demonstrate the hydrolysis of gangliosides fucosyl-GM1 and fucosyl-GD1b by purified human liver alpha-L-fucosidase in the absence of activator proteins and/or detergents.     

High-performance liquid chromatographic analysis of genistein and other isoflavonoids from heartwood of Ougeinia dalbergioides

A simple binary gradient HPLC method employing a Symmetry C18 column is described for the analysis of genistein, ougeinin, homoferririn, 2',4',5,7-tetrahydroxy-6-methyl isoflavone and 2',4',8-trihydroxy-6-methoxy-7-methyl isoflavone present in heartwood extract of Ougeinia dalbergioides.     

High-performance liquid chromatographic analysis of the antituberculosis drugs aconiazide and isoniazid

Reversed-phase HPLC methods are described for determining the stability and concentration certification of the antituberculosis prodrug aconiazide (ACON) in aqueous dosing solution and for assessing the concentrations of ACON and isoniazid (INH) in plasma from ACON-treated male and female Fischer-344 rats. ACON was analyzed in plasma by direct injection; it was separated on a 250 × 4.6 mm I.D. 5 μm C₁₈ column using a 40% aqueous methanol mobile phase containing 5 g/l ammonium formate, and detected at 313 nm. INH was determined in the plasma of treated rats after a two-step precipitation of plasma proteins; it was separated on a 250 mm × 4.6 mm I.D. 5 μm CN column, eluted with 5% aqueous isopropanol containing 5 g/l ammonium formate, and detected with an electrochemical detector at +0.8 V. These methods allow a simple, rapid, and reliable determination of ACON and INH in plasma down to 0.1 μg/ml.     

High-performance liquid chromatographic analysis of isoxicam in human plasma and urine

A sensitive, selective, and rapid high-performance liquid chromatographic procedure was developed for the determination of isoxicam in human plasma and urine. Acidified plasma or urine were extracted with toluene. Portions of the organic extract were evaporated to dryness, the residue dissolved in tetrahydrofuran (plasma) or acetonitrile (urine) and chromatographed on a μBondapak C₁₈ column preceded by a 4–5 cm × 2 mm I.D. column packed with Corasil C₁₈. Quantitation was obtained by UV spectrometry at 320 nm. Linearity in plasma ranged from 0.2 to 10 μg/ml. Recoveries from plasma samples seeded with 1.8, 4 and 8 μg/ml isoxicam were 1.86 ± 0.077, 4.10 ± 0.107 and 8.43 ± 0.154 μg/ml with relative standard deviations of 3.3%, 2.5% and 5.4%, respectively. The linearity in urine ranged from 0.125 to 2 μg/ml. The precision of the method was 3.3–9.0% relative standard deviation over the linear range.