Gas chromatographic-mass spectrometric analysis of urinary sugar and sugar alcohols during pregnancy

Optimization of hydrolysis conditions of alginate based on high performance liquid chromatography

Alginate is the most abundant polysaccharide compound in brown algae, which is widely used in various fields. At present, the determination of the content of alginate is mostly carried out using sulfuric acid and trifluoroacetic acid hydrolysis followed by the determination of the content, but the results are not satisfactory, and there are problems such as low hydrolysis degree and low recovery rate. Therefore, in this study, based on the optimization of high performance liquid chromatographic conditions for pre-column derivatization of 1-phenyl-3-methyl-5-pyrazolone (PMP), the hydrolysis effects of sulfuric acid, trifluoroacetic acid (TFA), oxalic acid, and formic acid were compared and the hydrolysis conditions were optimized. The results showed that formic acid was the best hydrolyzing acid. The optimal hydrolysis conditions were 95 % formic acid at 110 °C for 10 h. The hydrolysis effect was stable, with high recovery and low destruction of monosaccharides, which made it possible to introduce formic acid into the subsequent polysaccharide hydrolysis. The pre-column derivatization high performance liquid chromatography method established in this study was accurate and reliable, and the hydrolysis acid with better effect was screened, which provided a theoretical basis for the subsequent determination of alginate content.

Identification of a novel component leading to anti-tumor activity besides the major ingredient cordycepin in Cordyceps militaris extract

In accordance with our previous study that was carried out to identify novel anti-tumor ingredients, chromatographic separation in combination with an anti-tumor activity assay was used for analysis of Cordyceps militaris extract in this study. Various modes of chromatography including reversed-phase, cation-exchange and anion-exchange were used to separate components of Cordyceps militaris, which showed various chemical properties. Anti-tumor activity of each fraction was assessed by a Hoechst staining-based apoptosis assay using malignant melanoma MeWo cells. By these repeated approaches through chromatographic segregation and cell biological assay, we finally succeeded in identifying the target substance from a certain fraction that included neutral hydrophilic components using a pre-column and post-column chlorine adduct ionization LC-APCI-MS method. The target substance was a mono-carbohydrate, xylitol, that induced apoptotic cell death in MeWo cells but not in normal human OUMS-24 fibroblasts. This is the first study showing that Cordyceps militaris extract contains a large amount of xylitol. Thus, our results will contribute greatly to uncovering the mysterious multifunctional herbal drug Cordyceps militaris as an anti-tumor agent.

Determination of oligosaccharides and monosaccharides in Hakka rice wine by precolumn derivation high-performance liquid chromatography

This article presents a precolumn derivatization procedure with 1-phenyl-3-methyl-5-pyrazolone (PMP) reagent to detect oligosaccharides and monosaccharides in Hakka rice wine. The subsequent separation of the derivatized glucose–PMP also was performed using a mobile phase consisting of the molar ratio of acetonitrile to ammonium acetate buffer (0.1M) of 22:78 at a flow rate of 1.0 mL/min with the column temperature of 35°C, and the pH of ammonium acetate buffer at 5.5. The optimum derivation conditions were as follows: reaction temperature, 70°C; reaction time, 30 minutes; molar ratio of PMP to glucose, 10:1 (v/v); molar ratio of sodium hydroxide to glucose, 3:1 (v/v). The recovery rates were between 93.13% and 102.08% with relative standard deviation of 0.96–2.48%. The established method provides sufficient sensitivity with values of limit of detection of 0.09–0.26 mg/L and limit of quantification of 0.27–0.87 mg/L for determination of oligosaccharides and monosaccharides.

The perinatal transition of the circulating metabolome in a nonhuman primate

INTRODUCTION

The fetal-to-neonatal transition is one of the most complex processes in biological existence; much is unknown about this transition on the molecular and biochemical level. Based on growing metabolomics literature, we hypothesize that metabolomic analysis will reveal the key biochemical intermediates that change during the birth transition.

RESULTS

Using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC-TOFMS), we identified 100 metabolites that changed during this transition. Of these 100 metabolites, 23 demonstrated significant change during the first 72 h. Of note, four intermediates of the tricarboxylic acid (TCA) cycle were identified (α-ketoglutaric acid, fumaric acid, malic acid, and succinyl-CoA), demonstrating a consistent rate of rise during the study. This may signify the transition of the neonate from a hypoxic in utero environment to an oxygen-rich environment. Important signaling molecules were also identified, including myo-inositol and glutamic acid.

DISCUSSION

GC × GC-TOFMS was able to identify important metabolites associated with metabolism and signaling. These data can be used as a baseline for normal birth transition, which may aid in future perinatal research investigations.

METHODS

Late-preterm Macaca nemestrina were delivered by hysterotomy, with plasma drawn from the cord blood and after birth at eight additional time points to 72 h of age.

Quantitative analysis of myo-inositol in urine, blood and nutritional supplements by high-performance liquid chromatography tandem mass spectrometry

Myo-inositol plays key physiological functions, necessitating development of methodology for quantification in biological matrices. Limitations of current mass spectrometry-based approaches include the need for a derivatisation step and/or sample clean-up. In addition, co-elution of glucose may cause ion suppression of myo-inositol signals, for example in blood or urine samples. We describe an HPLC-MS/MS method using a lead-form resin based column online to a triple quadrupole tandem mass spectrometer, which requires minimum sample preparation and no derivatisation. This method allows separation and selective detection of myo-inositol from other inositol stereoisomers. Importantly, inositol was also separated from hexose monosaccharides of the same molecular weight, including glucose, galactose, mannose and fructose. The inter- and intra-assay variability was determined for standard solutions and urine with inter-assay coefficient of variation (CV) of 1.1% and 3.5% respectively, while intra-assay CV was 2.3% and 3.6%. Urine and blood samples from normal individuals were analysed.

Quantification of monosaccharides through multiple-reaction monitoring liquid chromatography/mass spectrometry using an aminopropyl column

A simple, sensitive, and reproducible quantitative liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was designed for the simultaneous quantification of monosaccharides derived from glycoprotein and blood serum using a multiple-reaction monitoring (MRM) approach. Sialic acids and neutral monosaccharides were efficiently separated using an amino-bonded silica phase column. Neutral monosaccharide molecules were detected as their aldol acetate anion adducts [M + CH(3)CO(2)](-) using electrospray ionization in negative ion MRM mode, while sialic acids were detected as deprotonated ions [M-H](-). The new method did not require a reduction step, and exhibited very high sensitivity to carbohydrates with limits of detection of 1 pg for the sugars studied. The linearity of the described approach spanned over three orders of magnitude (pg to ng). The method was validated for monosaccharides originating from N-linked glycans attached to glycoproteins and glycoproteins found in human blood serum. The method effectively quantified monosaccharides originating from as little as 1 microg of glycoprotein and 5 microL of blood serum. The method was robust, reproducible, and highly sensitive. It did not require reduction, derivatization or postcolumn addition of reagents.

Multiple-reaction monitoring liquid chromatography mass spectrometry for monosaccharide compositional analysis of glycoproteins

A simple, sensitive, and rapid quantitative LC-MS/MS assay was designed for the simultaneous quantification of free and glycoprotein bound monosaccharides using a multiple reaction monitoring (MRM) approach. This study represents the first example of using LC-MS/MS methods to simultaneously quantify all common glycoprotein monosaccharides, including neutral and acidic monosaccharides. Sialic acids and reduced forms of neutral monosaccharides are efficiently separated using a porous graphitized carbon column. Neutral monosaccharide molecules are detected as their alditol acetate anion adducts [M + CH(3)CO(2)](-) using electrospray ionization in negative ion MRM mode, while sialic acids are detected as deprotonated ions [M - H](-). The new method exhibits very high sensitivity to carbohydrates with limits of detection as low as 1 pg for glucose, galactose, and mannose, and below 10 pg for other monosaccharides. The linearity of the described approach spans over three orders of magnitudes (pg to ng). The method effectively quantified monosaccharides originating from as little as 1 microg of fetuin, ribonuclease B, peroxidase, and alpha(1)-acid glycoprotein human (AGP) with results consistent with literature values and with independent CE-LIF measurements. The method is robust, rapid, and highly sensitive. It does not require derivatization or postcolumn addition of reagents.

Urinary levoglucosan as a biomarker of wood smoke exposure: observations in a mouse model and in children

BACKGROUND

Biomass smoke is an important source of particulate matter (PM), and much remains to be discovered with respect to the human health effects associated with this specific PM source. Exposure to biomass smoke can occur in one of two main categories: short-term exposures consist of periodic, seasonal exposures typified by communities near forest fires or intentional agricultural burning, and long-term exposures are chronic and typified by the use of biomass materials for cooking or heating. Levoglucosan (LG), a sugar anhydride released by combustion of cellulose-containing materials, is an attractive candidate as a biomarker of wood smoke exposure.

OBJECTIVES

In the present study, Balb/c mice and children were assessed for LG in urine to determine its feasibility as a biomarker.

METHODS

We performed urinary detection of LG by gas chromatography/mass spectrometry after intranasal instillations of LG or concentrated PM (mice) or biomass exposure (mice or humans).

RESULTS

After instillation, we recovered most of the LG within the first 4 hr. Experiments using glucose instillation proved the specificity of our system, and instillation of concentrated PM from wood smoke, ambient air, and diesel exhaust supported a connection between wood smoke and LG. In addition, LG was detected in the urine of mice exposed to wood smoke. Finally, a pilot human study proved our ability to detect LG in urine of children.

CONCLUSIONS

These results demonstrate that LG in the lungs is detectable in the urine of both mice and humans and that it is a good candidate as a biomarker of exposure to biomass smoke.

Quality control of Cordyceps sinensis, a valued traditional Chinese medicine

Cordyceps sinensis, a well-known and valued traditional Chinese medicine, is also called DongChongXiaCao (winter worm summer grass) in Chinese. It is commonly used to replenish the kidney and soothe the lung for the treatment of fatigue, night sweating, hyposexualities, hyperglycemia, hyperlipidemia, asthemia after severe illness, respiratory disease, renal dysfunction and renal failure, arrhythmias and other heart disease, and liver disease. As the rarity and upstanding curative effects of natural Cordyceps, several mycelial strains have been isolated from natural Cordyceps and manufactured in large quantities by fermentation technology, and they are commonly sold as health food products in Asia. In addition, some substitutes such as Cordyceps militaris also have been used and adulterants also confused the market. Therefore, quality control of C. sinensis and its products is very important to ensure their safety and efficacy. Herein, markers and analytical methods for quality control of Cordyceps were reviewed and discussed.

Simultaneous determination of glucose, 1,5-anhydrod-glucitol and related sugar alcohols in serum by high-performance liquid chromatography with benzoic acid derivatization

A new, simple and sensitive pre-column high-performance chromatographic method for the determination of diabetes marker d-glucose, 1,5-anhydro-d-glucitol and related compounds is reported. Sugars (d-glucose, d-galactose, d-mannose, sucrose and arabinose) were derivatized with benzoic acid (BA) at 80 degrees C for 60 min. l-Fucose, fructose, d-lactose, l-rhamnose, arabinose and ascorbic acid were not reacted. Sugar alcohols (xylitol, erythritol, mannitol, sorbitol myo-inositol) were also derivatized with BA at 80 degrees C for 60 min. The fluorescence derivatives were separated on a TSK amide 80 column (4.6 mm i.d. x 250 mm, 5 microm) with acetonitrile-50 mm acetate buffer (pH 5.6; 4:96, v/v) as the mobile phase. The detection wavelength of beizoic acid derivatives was lambda(ex) 275 nm and lambda(em) 315 nm. The detection limits of sugars were 10-80 microg/mL. The calibration graphs were linear up to 10 mg/mL. The relative standard deviations of 500 microg/mL sugars were 7.0-7.3%. The proposed method was compared with the enzymatic photometric glucose analysis method (Glucose B-Test II Wako). The correlation coefficient was 0.83 (n = 20) and y = 0.82x + 5.91, where y and x are concentrations in microg/mL obtained by the proposed pre-column HPLC and enzyme-photometric method, respectively. The detection limits of sugar alcohols were 100-1000 ng/mL. The calibration graphs were linear to 50 microg/mL and relative standard deviations of 10 microg/mL were 7.2-8.2%. The 1,5-AG data by the proposed method was also compared with the enzymatic photometric 1,5-AG analysis method (Rana AG 1,5-AG determination kit, Nihon Kayaku) and good correlation (r = 0.91, n = 20) was also obtained. The proposed method was applied to the simultaneous determination of d-glucose, 1,5-AG and related sugar alcohols in serum from healthy males.

Sensitive LC MS quantitative analysis of carbohydrates by Cs+ attachment

The development of a sensitive assay for the quantitative analysis of carbohydrates from human plasma using LC/MS/MS is described in this paper. After sample preparation, carbohydrates were cationized by Cs(+) after their separation by normal phase liquid chromatography on an amino based column. Cesium is capable of forming a quasi-molecular ion [M + Cs](+) with neutral carbohydrate molecules in the positive ion mode of electrospray ionization mass spectrometry. The mass spectrometer was operated in multiple reaction monitoring mode, and transitions [M + 133] --> 133 were monitored (M, carbohydrate molecular weight). The new method is robust, highly sensitive, rapid, and does not require postcolumn addition or derivatization. It is useful in clinical research for measurement of carbohydrate molecules by isotope dilution assay.

The application of nuclear magnetic resonance-based metabonomics to the dominant–submissive rat behavioral model

Nuclear magnetic resonance (NMR) methods were used to study whether there are differences in the urine content between behaviorally distinct groups of rats: dominant and submissive. The dominant-submissive relationships (DSRs) were established in rat pairs competing for access to the feeder filled with sweetened milk. Dominant rats spend significantly longer amounts of time at the feeder than do their submissive partners. During a 2-week period, rats were tested for the DSR. At the end of the second week, behavioral groups of rats were selected and urine was collected during a 3.5-h time period. Principal component analysis revealed a metabolite from milk sugar, galactose, as a discriminating factor between rats classified as dominant and those classified as submissive. Measurements of galactose showed that the amount present in the urine correlated with the time spent in the feeder zone, thereby supporting the time criterion established for the DSR model.

Analysis of polyols in urine by liquid chromatography-tandem mass spectrometry: a useful tool for recognition of inborn errors affecting polyol metabolism

Several inborn errors of metabolism with abnormal polyol concentrations in body fluids are known to date. Most of these defects can be diagnosed by the assessment of urinary concentrations of polyols. We present two methods using tandem mass spectrometry for screening for inborn errors affecting polyol metabolism. Urine samples supplemented with internal standards ([13C4]erythritol, [13C2]arabitol and [2H3]sorbitol) were desalted by a mixed-bed ion-exchange resin. Separation was achieved by two different columns. Sugar isomers could not be separated using a Prevail Carbohydrate ES 54 column (method 1), whereas with the other column (Aminex HPX-87C) separation of the isomers was achieved (method 2). Multiple reaction monitoring polyol detection was achieved by tandem mass spectrometry with an electron ion-spray source operating in the negative mode. Age-related reference ranges of polyols (erythritol, treitol, arabitol, ribitol, xylitol, galactitol, mannitol, sorbitol, sedoheptitol and perseitol) in urine were established. The applicability of the method was demonstrated by the abnormal polyol concentrations observed in patients with transaldolase deficiency, ribose-5-phosphate isomerase deficiency and classical galactosaemia. This paper describes two methods for the analysis of urinary polyols by liquid chromatography-tandem mass spectrometry. Method 1 is a fast screening method with the quantification of total isomers and method 2 is a more selective method with the separate quantification of the polyols. Both methods can be used for diagnosing inborn errors of metabolism affecting polyol metabolism.

Electron ionization mass spectra and their reproducibility for trialkylsilylated derivatives of organic acids, sugars and alcohols

Mass spectra of trialkylsilyl derivatives of fatty acids, dicarboxylic acids, hydroxyacids, oxoacids, sugars, amino acids and alcohols were obtained. Amino acids were analyzed as tert-butyldimethylsilyl derivatives; all other model compounds were analyzed as trimethylsilyl derivatives. Reproducibility of the electron ionization (EI) mass spectra for the derivatives obtained was discussed. It was shown that, for many investigated derivatives, composition of the respective mass spectra depended greatly on ion source contamination. The trimethylsilylated alpha-tocopherol mass spectrum composition was most significantly influenced by ion source contamination. This compound can be used to test ion source contamination.

Sensitive and simple determination of mannitol in human brain tissues by gas chromatography-mass spectrometry

A simple, reliable and sensitive gas chromatographic-mass spectrometric method was devised to determine the level of mannitol in various human brain tissues obtained at autopsy. Mannitol was extracted with 10% trichloroacetic acid solution which effectively precipitated brain tissues. The supernatant was washed with tert.-butyl methyl ether to remove other organic compounds and to neutralize the aqueous solution. Mannitol was then derivatized with 1-butaneboronic acid and subjected to GC-MS. Erythritol was used as an internal standard. For quantitation, selected ion monitoring with m/z 127 and 253 for mannitol and m/z 127 for internal standard were used. Calibration curves were linear in concentration range from 0.2 to 20 microg/0.1 g and correlation coefficients exceeded 0.99. The lower detection limit of mannitol in distilled water was 1 ng/0.1 g. Mannitol was detected in control brain tissues, as a biological compound, at a level of 50 ng/0.1 g. The precision of this method was examined with use of two different concentrations, 2 and 20 microg/0.1 g, and the relative standard deviation ranged from 0.8 to 8.3%. We used this method to determine mannitol in brain tissues from an autopsied individual who had been clinically diagnosed as being brain dead. Cardiac arrest occurred 4 days later.