scholarly journals Urinary Excretion of Homocysteine-Thiolactone in Humans

2005 ◽  
Vol 51 (2) ◽  
pp. 408-415 ◽  
Author(s):  
Grazyna Chwatko ◽  
Hieronim Jakubowski
Keyword(s):  
Urinary Excretion ◽  
Human Body ◽  
Human Urine ◽  
Biological Fluids ◽  
Hplc Method ◽  
Biological Integrity ◽  
Amino Group ◽  
Urinary Ph ◽  
Homocysteine Thiolactone ◽  
Postcolumn Derivatization

Abstract Background: A metabolite of homocysteine (Hcy), the thioester Hcy-thiolactone, has been implicated in coronary heart disease in humans. Because inadvertent reactions of Hcy-thiolactone with proteins can lead to cell and tissue damage, the ability to detoxify or eliminate Hcy-thiolactone is essential for biological integrity. We examined the hypothesis that the human body eliminates Hcy-thiolactone by urinary excretion. Methods: We used a sensitive HPLC method with postcolumn derivatization and fluorescence detection to examine Hcy-thiolactone concentrations in human urine and plasma. Results: We discovered a previously unknown pool of Hcy-thiolactone in human urine. Urinary concentrations of Hcy-thiolactone (11–485 nmol/L; n = 19) were ∼100-fold higher than those in plasma (<0.1–22.6 nmol/L; n = 20). Urinary Hcy-thiolactone accounted for 2.5–28.3% of urinary total Hcy, whereas plasma Hcy-thiolactone accounted for <0.002–0.29% of plasma total Hcy. Urinary concentrations of Hcy-thiolactone, but not of total Hcy, were negatively correlated with urinary pH. Clearance of Hcy-thiolactone, relative to creatinine, was 0.21–6.96. In contrast, relative clearance of Hcy was 0.001–0.003. Conclusions: The analytical methods described here can be used to quantify Hcy-thiolactone in biological fluids. Using these methods we showed that the human body eliminates Hcy-thiolactone by urinary excretion. Our data also suggest that the protonation status of its amino group affects Hcy-thiolactone excretion.

scholarly journals A green approach to the analysis of co-administered ampicillin/sulbactam and paracetamol in human urine

2021 ◽  
Vol 72 (2) ◽  
pp. 259-274
Author(s):  
BASMA M. SELIM ◽  
RANDA A. ABDELSALAM ◽  
ALAA EL-GINDY ◽  
BASMA G. EID ◽  
THIKRYAT NEAMATALLAH ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Human Urine ◽  
Direct Injection ◽  
Potassium Dihydrogen Phosphate ◽  
Hplc Method ◽  
Urine Samples ◽  
Environmentally Benign ◽  
Dihydrogen Phosphate ◽  
Mobile Phase Flow Rate ◽  
Green Approach

Abstract The novelty of this work is the simultaneous analysis of sulbactam (SUL), ampicillin (AMP), and paracetamol (PARA) in human urine samples, using the environmentally benign RP-HPLC method. A C18 column was used in chromatographic separation using potassium dihydrogen phosphate (10 mmol L–1, pH 5)/ethanol (90 %, V/V) as the mobile phase; flow rate was 1.00 mL min–1. UV detection at 220 nm was used for quantification. The proposed method showed good linearity in the concentration ranges of 2.20–250.00 μg mL–1 for SUL, 2.50–250.00 μg mL–1 for PARA, and 14.50–250.00 μg mL–1 for AMP. Direct injection of urine samples with no prior extraction was performed. This method was found successful in moving towards greener studies of drugs’ urinary excretion, by decreasing hazardous solvent consumption and waste. Moreover, the method was applied to investigate the urinary excretion of the drugs and possible interaction between ampicillin and paracetamol.

Application of an LC-MS/MS Method to a Urinary Excretion Study of Triflusal and its Main Metabolite 2-hydroxy-4-trifluoromethyl Benzoic Acid in Human Urine

2020 ◽  
Vol 16 (3) ◽  
pp. 328-334
Author(s):  
Jie Ge ◽  
Jin-Wen Wang ◽  
Qi-Yan Guo ◽  
Ai-Dong Wen
Keyword(s):  
Benzoic Acid ◽  
Urinary Excretion ◽  
Human Urine ◽  
Multiple Reaction Monitoring ◽  
Main Metabolite ◽  
Linear Relationships ◽  
Pharmacokinetic Properties ◽  
Liquid Chromatography Tandem Mass ◽  
Excretion Study ◽  
Acetate Aqueous Solution

Objective: A validated liquid chromatography-tandem mass spectrometry method (LCMS/ MS) was established to simultaneously determine the concentration of triflusal and its main metabolite 2-hydroxy-4-trifluoromethyl benzoic acid(HTB) in human urine. Methods: The separation was performed on a Dikma C18 column using isocratic elution with acetonitrile-4 mmol/L ammonium acetate aqueous solution containing 0.3 % formic acid water (78: 28, V/V). The method involved extraction with methanol using protein precipitation. The precursor-toproduct ion transitions with multiple reaction monitoring was m/z 247.1→161.1, 204.8→106.7and 136.9→93.0 for triflusal, HTB and salicylic acid(IS), respectively. The method showed good linear relationships over the ranges of 0.08 to 48 μg/mL and0.5 to 50 μg/mL. Results: It was the first time that a urinary excretion study of triflusal capsule as oral. The cumulative urinary recovery showed 8.5% and 2.7% for triflusal and HTB, respectively. Conclusion: This method was successfully used for evaluating the pharmacokinetic properties of triflusal and HTB in urine in Chinese healthy subjects.

Development of an HPLC method for measuring orally administered 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in biological fluids

1990 ◽  
Vol 36 (1) ◽  
pp. 5-8 ◽  
Author(s):  
J G Goddard ◽  
G J Kontoghiorghes
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Hplc Method ◽  
Iron Chelators ◽  
Serum Samples ◽  
Thalassemic Patient ◽  
Serum And Urine

Abstract "High-performance" liquid-chromatographic (HPLC) methods have been developed for identifying 1-substituted 2-alkyl-3-hydroxypyrid-4-one iron chelators in serum and urine. Ion pairing with heptane- or octanesulfonic acid in pH 2.0-2.2 phosphate buffer and reversed-phase chromatography were required to separate these compounds from endogenous compounds in both biological fluids. In both the 2-methyl and 2-ethyl series of 1-substituted compounds (H, methyl, ethyl, or propyl) the elution times increased in accordance with the n-octanol/water partition coefficients (propyl greater than ethyl greater than H greater than methyl). Urine samples were filtered (0.4 microns pore size) and injected either undiluted or after dilution with elution buffer. After the addition of internal standard, the plasma or serum samples were deproteinized by treatment with HCIO4, 0.5 mol/L, centrifuged, and the supernates were injected directly onto the HPLC. Using these procedures, we could identify 1,2-dimethyl-3-hydroxypyrid-4-one (L1) in the serum and urine of a thalassemic patient who had received a 3-g dose of the drug and in the urine of other patients who had received the same dose. One or more possible metabolites were also observed in the chromatograms of both urine and serum. The 24-h urinary output of L1 (0.22-2.37 g) and iron (10.6-71.5 mg) varied but there was no correlation between the two with respect to quantity or concentration. Instead, urinary iron output was higher in patients with a greater number of transfused units of erythrocytes. This is the first study in humans to show that L1 is absorbed from the gut, enters the circulation, and is excreted in the urine.

Reply to comments on ‘An HPLC method for the measurement of free cortisol/cortisone ratio in human urine’

2007 ◽  
Vol 21 (11) ◽  
pp. 1222-1222
Author(s):  
Al Sharef O ◽  
Feely J ◽  
Scott KR ◽  
Kavanagh PV ◽  
Sharma SC
Keyword(s):  
Human Urine ◽  
Hplc Method ◽  
Free Cortisol

A rapid and simple HPLC method for the analysis of propofol in biological fluids

2007 ◽  
Vol 44 (3) ◽  
pp. 680-682 ◽  
Author(s):  
Xavier Cussonneau ◽  
Els De Smet ◽  
Kristof Lantsoght ◽  
Jean-Paul Salvi ◽  
Magali Bolon-Larger ◽  
...  
Keyword(s):  
Biological Fluids ◽  
Hplc Method

scholarly journals Solid-Phase Extraction and Reverse-Phase HPLC: Application to Study the Urinary Excretion Pattern of Benzophenone-3 and its Metabolite 2,4-Dihydroxybenzophenone in Human Urine

2008 ◽  
Vol 3 ◽  
pp. ACI.S396 ◽  
Author(s):  
Helena Gonzalez ◽  
Carl-Eric Jacobson ◽  
Ann-Marie Wennberg ◽  
Olle Larkö ◽  
Anne Farbrot
Keyword(s):  
Solid Phase Extraction ◽  
Urinary Excretion ◽  
Human Urine ◽  
Solid Phase ◽  
Whole Body ◽  
Phase Extraction ◽  
Reverse Phase Hplc ◽  
Reverse Phase ◽  
Excretion Pattern ◽  
Relative Standard

Background Benzophenone-3 (BZ-3) is a common ultraviolet (UV) absorbing compound in sunscreens. It is the most bioavailable species of all UV-absorbing compounds after topical application and can be found in plasma and urine. Objectives The aim of this study was to develop a reverse-phase high performance liquid chromatography (HPLC) method for determining the amounts BZ-3 and its metabolite 2,4-dihydroxybenzophenone (DHB) in human urine. The method had to be suitable for handling a large number of samples. It also had to be rapid and simple, but still sensitive, accurate and reproducible. The assay was applied to study the urinary excretion pattern after repeated whole-body applications of a commercial sunscreen, containing 4% BZ-3, to 25 healthy volunteers. Methods Each sample was analyzed with regard to both conjugated/non-conjugated BZ-3 and conjugated/non-conjugated DHB, since both BZ-3 and DHB are extensively conjugated in the body. Solid-phase extraction (SPE) with C8 columns was followed by reverse-phase HPLC. For separation a Genesis C18 column was used with an acethonitrile-water mobile phase and the UV-detector was set at 287 nm. Results The assay was linear r 2 > 0.99, with detection limits for BZ-3 and DHB of 0.01 µmol L-1 and 0.16 µmol L-1 respectively. Relative standard deviation (RSD) was less than 10% for BZ-3 and less than 13% for DHB. The excretion pattern varied among the human volunteers; we discerned different patterns among the individuals. Conclusions The reverse-phase HPLC assay and extraction procedures developed are suitable for use when a large number of samples need to be analyzed and the method fulfilled our objectives. The differences in excretion pattern may be due to differences in enzyme activity but further studies, especially about genetic polymorphism, need to be performed to verify this finding.

scholarly journals NanoMIP-Based Solid Phase Extraction of Fluoroquinolones from Human Urine: A Proof-of-Concept Study

Separations ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 226
Author(s):  
Matteo Chiarello ◽  
Laura Anfossi ◽  
Simone Cavalera ◽  
Fabio Di Di Nardo ◽  
Thea Serra ◽  
...  
Keyword(s):  
Solid Phase Extraction ◽  
Human Urine ◽  
Solid Phase ◽  
Extraction Methods ◽  
Hplc Method ◽  
Limited Attention ◽  
Preliminary Treatment ◽  
Phase Extraction ◽  
Proof Of Concept ◽  
Binding Behavior

NanoMIPs that are prepared by solid phase synthesis have proven to be very versatile, but to date only limited attention has been paid to their use in solid phase extraction. Thus, since nanoMIPs show close similarities, in terms of binding behavior, to antibodies, it seems relevant to verify if it is possible to use them as mimics of the natural antibodies that are used in immunoextraction methods. As a proof-of-concept, we considered prepared nanoMIPs against fluoroquinolone ciprofloxacin. Several nanoMIPs were prepared in water with polymerization mixtures of different compositions. The polymer with the highest affinity towards ciprofloxacin was then grafted onto a solid support and used to set up a solid phase extraction–HPLC method with fluorescence detection, for the determination of fluoroquinolones in human urine. The method resulted in successful selection for the fluoroquinolone antibiotics, such that the nanoMIPs were suitable for direct extraction of the antibiotics from the urine samples at the µg mL−1 level. They required no preliminary treatment, except for a 1 + 9 (v/v) dilution with a buffer of pH 4.5 and they had good analyte recovery rates; up to 85% with precision in the range of 3 to 4.5%, without interference from the matrix. These experimental results demonstrate, for the first time, the feasibility of the use of nanoMIPs to develop solid phase extraction methods.

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