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A straightforward distance-based paper analytical device (dPAD) was developed for monitoring sarcosine levels in human samples for the rapid diagnosis and prognosis of prostate cancer and related symptoms. This assay eliminates the need for the expensive horseradish peroxidase (HRP) enzyme by utilizing carbon nanodots (CDs) as a peroxidase-like nanozyme. The proposed dPAD sensor consists of a sample zone pre-deposited with sarcosine oxidase (SOx) and CDs, and a detection zone containing 3,3′,5,5′-tetramethylbenzidine (TMB). When a solution containing sarcosine is added to the sample zone, hydroxyl radicals (•OH) are produced through SOx oxidation and subsequent peroxidase catalysis by the CDs. The formed •OH radicals immediately flow to the detection zone via capillary force, where they oxidize TMB, resulting in a visible colour change from colourless to blue. Sarcosine quantification is effortlessly accomplished by measuring the distance of the blue colour in the detection zone. The developed dPAD offers a linear working range between 12.5 and 35.0 nmol L−1 (R2 = 0.9959) and a detection limit (LOD) of 10.0 nmol L−1. This covers the clinical range for urinary sarcosine determination, thereby suggesting no additional sample preparation or dilution is needed. The sensor shows high precision with the highest relative standard deviation (RSD) of 4.58% and demonstrates excellent selectivity with no observed interferences. Furthermore, recovery studies in human control urine samples ranged from 98.67 to 101.50%, with the highest RSD of 2.03%. Correspondingly, our dPAD method showed a great match with the performance of a commercial ELISA method for detecting sarcosine in human control serum. The sensor is more cost-effective, user-friendly, and accessible than previous methods. Overall, the proposed method represents a promising analytical tool for sarcosine quantification. The concept is also applicable for broader analytical applications in detecting other biomolecules. [ABSTRACT FROM AUTHOR]

Selective and sensitive sarcosine detection is crucial due to its recent endorsement as a prostate cancer (PCa) biomarker in clinical diagnosis. The reduced graphene oxide-cobalt nickel tungsten boron oxides (CoNiWBO/rGO) nanocomposite is developed as a non-enzymatic electrochemical sensor for sarcosine detection in PCa patients' serum. CoNiWBO/rGO is synthesized by the chemical reduction method via a one-pot reduction method followed by calcination at 500 °C under a nitrogen environment for 2 h and characterized by UV-Vis, XRD, TGA, and SEM. CoNiWBO/rGO is then deposited on a glassy carbon electrode, and sarcosine sensing parameters are optimized, including concentration and pH. This non-enzymatic sensor is employed to directly determine sarcosine in serum samples. Differential pulse voltammetry (DPV) and linear sweep voltammetry (LSV) are employed to monitor the electrochemical behavior where sarcosine binding leads to oxidation. Chronoamperometric studies show the stability of the developed sensor. The results demonstrate a wide linear range from 0.1 to 50 µM and low limits of detection, i.e., 0.04 µM and 0.07 µM using DPV and LSV respectivel. Moreover, the calculated recovery of sarcosine in human serum of prostate cancer patients is 78–96%. The developed electrochemical sensor for sarcosine detection can have potential applications in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Recycled cellulose extracted from office wastepaper is an attractive material for manufacturing disposable sensors. By formulating a cellulose hydrogel nanocomposite, the sensitivity of the colorimetric sensor is notably improved, enabling simple observation of the color changes with the naked eye. In this study, a recycled cellulose/PVA/CMC-GO/NQS hydrogel nanocomposite was successfully prepared and applied as a noninvasive wearable sarcosine sensor integrated into a diaper. The prepared hydrogel-based colorimetric sensor operates via a nonenzymatic reaction using 1,2-naphthoquinone-4-sulfonic acid sodium salt (NQS) as a coloring reagent. NQS-functionalized graphene oxide (GO) facilitates the color-producing reaction by increasing NQS molecules adhering to both sides of the GO sheet via π-π interactions. This sensor exhibits a dramatic color change with a linear range of 0–100 μM (R2 = 0.9550) and a detection limit of 10.0 μM, indicating that sarcosine can be effectively detected at its cutoff value (25.0 μM) for detecting prostate cancer (PCa). The sensing results tested in human urine samples were validated with a standard LDI-MS, which provided satisfactory results. Consequently, this sensor might be an alternative wearable sarcosine sensor for prostate cancer screening in the near future. [ABSTRACT FROM AUTHOR]

An original molecular imprinting photoelectrochemical (PEC) sensor for sarcosine detection based on stable lead-free inorganic halide double perovskite Cs2AgBiBr6 is proposed. Cs2AgBiBr6 as a lead-free halide perovskite material possesses several positive optoelectronic properties for PEC analysis, such as long-lived component to the charge-carrier lifetime, and strong absorption of visible light. At the same time, two-dimensional materials also offer excellent electronic and mechanical properties; thus, Bi2O2S was used and combined with Cs2AgBiBr6 to provide a stable and large photocurrent, which also benefits from the stability of perovskite Cs2AgBiBr6. Based on this novel PEC assay, the detection range for sarcosine was between 0.005 and 5000 ng/mL with a low detection limit of 0.002 ng/mL. This work also improved the adhibition of metal halide perovskite in analytical chemistry field, providing a novel way for other small molecule detection. [ABSTRACT FROM AUTHOR]

Flower-like core-shell nanostructures based on natural asphalt (NA) coated with nickel-layered double hydroxide nanosheets (Ni-LDH NSs) were synthesized for the first time. The synthetic nanostructures were successfully used as an efficient platform in the design of sarcosine (SAR) electrochemical aptasensor. SAR is considered an efficient biomarker for prostate cancer (PCa) diagnosis. However, the low concentration of SAR in urine, plasma, and tissue cells has limited the growth of SAR biosensors. The performance of the presented SAR aptasensor is very promising in being applied as a portable device in the identification of PCa. After drawing the calibration curve, the linear concentration range was obtained in two ranges from 5 pM to 100 nM and 100 nM to 7.9 μM, and the limit of detection (LOD) was calculated to be 1.6 pM. This study can provide a basis for wider research in various programs such as developing PCa diagnostic aptasensors and investigating the use of NA nanostructures in other electrochemical applications such as electrocatalysis and energy storage. [ABSTRACT FROM AUTHOR]

A fluorescence and colorimetric tandem dual-mode sensor was established by modulating fluorescence and oxidase-like activity via valence switching of cerium-based coordination polymer nanoparticles (Ce-CPNs) for the detection of sarcosine (Sar) which is considered as a potential biomarker for the diagnosis of prostate cancer (PCa). In the present research, sarcosine oxidase (SOX) specifically catalyzes the oxidation of Sar to yield H2O2 which can rapidly oxidize Ce(III)-CPNs to generate Ce(IV)-CPNs in appropriate alkaline solution. The generated Ce(IV)-CPNs create a markedly weakened fluorescent signal at 350 nm, while they can induce oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to generate blue TMBox through emerging good oxidase-like activity. The sensing platform can realize accurate, stable, and high-throughput detection of Sar because of the tandem dual signal output mechanism. More attractively, the chromogenic hydrogel sensing device using smartphone photographing has achieved perfect results for the on-site sensing of Sar in urine specimens without large experimental equipments, demonstrating its considerable clinical application potential in the early diagnosis of PCa. [ABSTRACT FROM AUTHOR]

Solute carriers (SLC) are important membrane transport proteins in normal and pathophysiological cells. The aim was to identify amino acid SLC(s) responsible for uptake of sarcosine and glycine in prostate cancer cells and investigate the impact hereon of hyperosmotic stress. Uptake of 14C-sarcosine and 3H-glycine was measured in human prostate cancer (PC-3) cells cultured under isosmotic (300 mOsm/kg) and hyperosmotic (500 mOsm/kg) conditions for 24 h. Hyperosmotic culture medium was obtained by supplementing the medium with 200 mM of the trisaccharide raffinose. Amino acid SLC expression was studied using RT-PCR, real-time PCR, and western blotting. siRNA knockdown of SNAT2 was performed. Experiments were conducted in at least 3 independent cell passages. The uptake of Sar and Gly was increased approximately 8–ninefold in PC-3 cells after 24 h hyperosmotic culture. PAT1 mRNA and protein could not be detected, while SNAT2 was upregulated at the mRNA and protein level. Transfection with SNAT2-specific siRNA reduced Vmax of Sar uptake from 2653 ± 38 to 513 ± 38 nmol mg protein−1 min−1, without altering the Km value (3.19 ± 0.13 vs. 3.42 ± 0.71 mM), indicating that SNAT2 is responsible for at least 80% of Sar uptake in hyperosmotic cultured PC-3 cells. SNAT2 is upregulated in hyperosmotic stressed prostate cancer cells and SNAT2 is responsible for cellular sarcosine and glycine uptake in hyperosmotic cultured PC-3 cells. Sar is identified as a substrate for SNAT2, and this has physiological implications for understanding cellular solute transport in prostate cancer cells. [ABSTRACT FROM AUTHOR]

A widely used herbicide for controlling weeds, glyphosate, is causing environmental pollution. It is necessary to remove it from environment using a cost-effective and eco-friendly method. The aims of this study were to isolate glyphosate-degrading bacteria and to optimize their degradative conditions required for bioremediation. Sixteen bacterial strains were isolated through enrichment and one strain, Rhodococcus soli G41, demonstrated a high removal rate of glyphosate than other strains. Response surface methodology was employed to optimize distinct environmental factors on glyphosate degradation of G41 strain. The optimal conditions for the maximum glyphosate degradation were found to have the NH4Cl concentration of 0.663% and glyphosate concentration of 0.115%, resulting in a maximum degradation of 42.7% after 7 days. Bioremediation analysis showed 47.1% and 40% of glyphosate in unsterile soil and sterile soil was removed by G41 strain after 14 days, respectively. The presence of soxB gene in G41 strain indicates that the glyphosate is degraded via the eco-friendly sarcosine pathway. The results indicated that G41 strain has the potential to serve as an in-situ candidate for bioremediation of glyphosate polluted environments. [ABSTRACT FROM AUTHOR]

Sarcosine is one of the known small molecule biomarkers to detect prostate cancer effectively. In the present work, we presented a very simple procedure and low-cost non-enzymatic method for the detection of Sarcosine. Zinc oxide (ZnO) nanoparticles were successfully synthesized, characterized and elucidated the morphology on the Indium tin oxide (ITO) surface, which showed uniform arrangement with a spherical shape. The ITO working electrode modified with ZnO exhibits better analytical characteristics for Sarcosine sensing with a linear range between 5 and 100 nM. The limit of detection was found to be low (7.5 nM) with excellent sensitivity and possess quick response time. Due to its high specificity and repeatability, the ITO/ZnO working electrode does not interfere with the other amino acids in the real samples. [ABSTRACT FROM AUTHOR]

Glycine betaine (GB) is a biologically important compound for microbial communities living in saline habitats most commonly employed as an organic osmolyte. At fluctuating salinity, halophilic microbes producing GB excrete it into environment making it available for heterotrophic/methylotrophic community members as a source of carbon, energy and nitrogen. Although many halolalkaliphilic bacteria have a potential for synthesis of GB as the main osmolyte, so far there was no targeted investigation of its microbial mineralization at soda lake conditions. In this work GB was used as substrate to enrich for GB-utilizing bacteria and archaea from sediments of hypersaline soda lakes located in southwestern Siberia. Aerobic enrichments at moderate and soda-saturated conditions (pH 10) resulted in isolation of several gammaproteobacterial strains identical in its 16S RNA gene to each other and to the known species Halomonas alkalicola. These isolates grew equally well with several methylated compounds: methylglycine (sarcosine), dimethylglycine (DMG), GB and choline (trimethylethanolamine). No growth was observed in aerobic hypersaline enrichments in presence of antibiotics indicating that bacteria are the main mineralizers of GB in hypersaline soda lakes at oxic conditions. In contrast, an anaerobic enrichment at 4 M Na+ and pH 9.7 targeting GB-utilizing haloalrchea was positive with sulfur as electron acceptor and resulted in isolation of a pure natronarchaeal culture belonging to the previously described genus of sulfur-reducing haloarchaea Halalkaliarchaeum. Anaerobic enrichments with GB at fermentative conditions were positive at salinities 2−4 M total Na+ (pH 10) and consisted of a bacterial component forming trimethyamine (TMA) and methylotrophic methanogens consuming the latter. In both cases the bacterial component belonged to the genus Natroniella (Halanaerobiia), while the methanogenic partner at 2 M Na+ was identified as Methanosalsum natronophilum and at 4 M Na+/48°C—as members of the methyl-reducing genus Methanonatronarchaeum. [ABSTRACT FROM AUTHOR]

Sarcosine has been identified as a key metabolite marker for monitoring and early diagnosis of metastatic prostate cancer (PCa), and it is detectable in the urine of patients. In the present study, a carbon past electrode modified with TiO2 nanoparticles in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid is proposed for the voltammetric determination of sarcosine in biological samples. Electrochemical impedance spectroscopy was used to study the charge transfer properties of the proposed electrode at the electrode–solution interface. Cyclic and differential pulse voltammetric methods were used to evaluate sarcosine electrochemical behaviour. Electrochemical oxidation of sarcosine on the new TiO2/ionic liquid carbon paste electrode (TiO2/IL/CPE) was carefully studied. The plot of oxidation peak current versus the concentration of sarcosine consists of two separate linear portions. The first part is for 0.1 to 1 mM (direct proportion) and the second one is for 1.0 to 5.0 mM of sarcosine (linear portion). The detection limit was 0.08 mM (3σ) in phosphate buffer (pH 11.5). The measurement and fabrication reproducibilities of the modified sensor were 1.7 and 3.46% for 0.6 mM sarcosine, respectively. The proposed method was successfully applied for the determination of sarcosine in a spiked real sample. [ABSTRACT FROM AUTHOR]

The reaction of pyrrolo[3,2,1-ij]quinoline-1,2-diones with methyl (het)aryl ketones gave the corresponding 1-(het)arylmethylidenepyrroloquinolin-2-ones, and 1,3-dipolar cycloaddition of the latter to azomethine ylide generated from sarcosine and paraformaldehyde afforded 4-acyl-1,4′,4′,6′-tetramethylspiro[pyrrolidine-3,1′-pyrrolo[3,2,1-ij]quinolin]-2′(4′H)-ones. The synthesized compounds were evaluated for inhibitory activity against blood coagulation factors Xa and XIa. [ABSTRACT FROM AUTHOR]

Purpose: Alcohol consumption is an established breast cancer risk factor, though further research is needed to advance our understanding of the mechanism underlying the association. We used global metabolomics profiling to identify serum metabolites and metabolic pathways that could potentially mediate the alcohol-breast cancer association.Methods: A cross-sectional analysis of reported alcohol consumption and serum metabolite concentrations was conducted among 211 healthy women 25-29 years old who participated in the Dietary Intervention Study in Children 2006 Follow-Up Study (DISC06). Alcohol-metabolite associations were evaluated using multivariable linear mixed-effects regression.Results: Alcohol was significantly (FDR p < 0.05) associated with several serum metabolites after adjustment for diet composition and other potential confounders. The amino acid sarcosine, the omega-3 fatty acid eicosapentaenoate, and the steroid 4-androsten-3beta,17beta-diol monosulfate were positively associated with alcohol intake, while the gamma-tocopherol metabolite gamma-carboxyethyl hydroxychroman (CEHC) was inversely associated. Positive associations of alcohol with 2-methylcitrate and 4-androsten-3beta,17beta-diol disulfate were borderline significant (FDR p < 0.10). Metabolite set enrichment analysis identified steroids and the glycine pathway as having more members associated with alcohol consumption than expected by chance.Conclusions: Most of the metabolites associated with alcohol in the current analysis participate in pathways hypothesized to mediate the alcohol-breast cancer association including hormonal, one-carbon metabolism, and oxidative stress pathways, but they could also affect risk via alternative pathways. Independent replication of alcohol-metabolite associations and prospective evaluation of confirmed associations with breast cancer risk are needed. [ABSTRACT FROM AUTHOR]

Carbon paste electrodes have been used for decades in electro-analytical screening, with numerous advancements in modifying electrochemical properties. Different materials have been utilized in various applications, encompassing electroanalytical techniques and healthcare sensing. The current research addresses the enhancement of the carbon paste electrode with ionic liquid and molecularly printed polymers for sensitive and selective detection of the sarcosine biomarker. The materials were characterized using their structural and morphological properties, and the roughness and surface area of the polymer were evaluated. The electrochemical response for sarcosine was obtained at a potential of 1.2 V by modifying the carbon paste electrode with ionic liquid and magnetic molecularly imprinted polymers (mMIPs). Under optimized conditions, the proposed method showed a concentration linear range of 2.0 × 10−7 to 1.04 × 10−4 mol L−1 and a low detection limit of 5.1 × 10−8 mol L−1. Aiming to demonstrate the efficiency of the proposed sensor, tests with biological samples were performed. The results showed robust recovery of sarcosine, ranging between 96 to 104% at two different concentration levels, affirming the efficacy of this method in determining sarcosine.Graphical Abstract: Carbon paste electrodes have been used for decades in electro-analytical screening, with numerous advancements in modifying electrochemical properties. Different materials have been utilized in various applications, encompassing electroanalytical techniques and healthcare sensing. The current research addresses the enhancement of the carbon paste electrode with ionic liquid and molecularly printed polymers for sensitive and selective detection of the sarcosine biomarker. The materials were characterized using their structural and morphological properties, and the roughness and surface area of the polymer were evaluated. The electrochemical response for sarcosine was obtained at a potential of 1.2 V by modifying the carbon paste electrode with ionic liquid and magnetic molecularly imprinted polymers (mMIPs). Under optimized conditions, the proposed method showed a concentration linear range of 2.0 × 10−7 to 1.04 × 10−4 mol L−1 and a low detection limit of 5.1 × 10−8 mol L−1. Aiming to demonstrate the efficiency of the proposed sensor, tests with biological samples were performed. The results showed robust recovery of sarcosine, ranging between 96 to 104% at two different concentration levels, affirming the efficacy of this method in determining sarcosine. [ABSTRACT FROM AUTHOR]

(3+2) Cycloaddition of azomethine ylide generated in situ from 11H-indeno[1,2-b]quinoxalin-11-one and proline to 3-nitro-2-trifluoro- (trichloro)methyl- and 3-nitro-2-phenyl-2H-chromenes upon heating in EtOH proceeded regio- and stereoselectively, resulting in the formation of spiro[chromeno[3,4-a]pyrrolizine-11,11'-indeno[1,2-b]quinoxalines]. An analogous reaction using ylide derived from sarcosine under the conditions of kinetic control led to preferential formation of diastereomeric spiro[chromeno[3,4-c]pyrrolidine-3,11'-indeno[1,2-b]quinoxalines] with different configuration of the spiro atom, which were transformed upon heating in DMSO into the thermodynamically more stable spiro[chromeno[3,4-c]pyrrolidine-1,11'-indeno[1,2-b]quinoxalines]. [ABSTRACT FROM AUTHOR]

The most worldwide used herbicide is glyphosate, phosphonomethylglycine (PMG). Consequently, a significant amount of PMG, its metabolites (sarcosine, SAR, and aminomethylphosphonic acid, AMPA) and the degradation product, methylphosphonic acid (MPA), reaches the soil, which acts as final sink. Because clays are one of the most reactive components of soils, expansive clays such as montmorillonite (Mt) are used to retain agriculture contaminants with some success. In this work, as a preliminary step for the evaluation of the risk that PMG, SAR, AMPA, and MPA occurrence could have on the environment, their adsorption on Mt surface was performed. The adsorption process was analyzed at constant adsorbate concentrations and two pH values to take into account the different protonation states of the amino group. DTA, XRD, zeta potential measurements, and XPS were used to identify the interactions or association mechanisms with the clay surface, the entry of adsorbates into the Mt interlayer, and electric charge changes on the Mt surface, and evaluate the acid-base surface complex constants, respectively. The interlayer thickness in acid media indicated that adsorbates are able to enter the interlayer in planar form. Besides, for the Mt-PMG sample, some PMG molecules could be also inserted as a bilayer or with a tilt angle of 52.4° in the interlayer. However, in alkaline media, the interlayer thickness indicated that the adsorbate arrangement differed from that of acidic media where PMG and MPA could have more than one orientation. The surface complex deprotonation constants were determined for the =NH+2 ⇆ =NH+H+ process, being 3.0, 5.0, and 7.3 for PMG, AMPA, and SAR, respectively. [ABSTRACT FROM AUTHOR]

Background: Left atrial appendage (LAA) closure (LAAC) by implantation of an occlusion device is an established cardiac intervention to reduce risk of stroke while avoiding intake of oral anticoagulation medication during atrial fibrillation. Cardiac interventions can alter local or systemic gene and protein expression. Effects of LAAC on systemic metabolism have not been studied yet. Objectives: We aimed to study the effects of interventional LAAC on systemic metabolism. Methods: Products of glycolysis, tricarboxylic acid and urea metabolism were analyzed by ESI-LC-MS/MS and MS/MS using the AbsoluteIDQ™ p180 Kit in plasma of 44 patients undergoing successful interventional LAAC at baseline (T0) and after 6 months (T1). Results: During follow up, plasma concentrations of several parameters of glycolysis and tricarboxylic acid cycle (TCA) and urea metabolism increased (alanine, hexose, proline, sarcosine), while others decreased (aspartate, glycine, SDMA, serine). Multivariate linear regression analysis showed that time after interventional LAAC was an independent predictor for metabolite changes, including the decrease of SDMA (beta −0.19, p < 0.01) and the increase of sarcosine (beta 0.16, p < 0.01). Conclusions: Successful interventional LAAC affects different pathways of the metabolome, which are probably related to cardiac remodeling. The underlying mechanisms as well as the long term effects have to be studied in the future. [ABSTRACT FROM AUTHOR]

In this work, physical properties such as density, refractive index and viscosity of aqueous diethanolamine sarcosinate (DEA-SAR) solution were measured at different temperatures. The knowledge of physical properties is necessary for the process design and simulation of acid gas absorber plant. Various concentrations of aqueous DEA-SAR solutions (0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) were investigated at temperature ranging from 298.15 to 333.15 K. The reported results showed an increment behavior in the physical properties with the increase in concentration isothermally, and a decreasing one with the rise in temperature of the solution at any given concentration. Empirical models were applied to correlate the experimental data of each physical property as a function of both concentration and temperature. A quantitative analysis of variation was carried out for estimating the significance of the physical property's data. [ABSTRACT FROM AUTHOR]

Sarcosine is an N-methyl derivative of the amino acid glycine, and its elevation in tissues and physiological fluids of patients with sarcosinemia could reflect a deficient pool size of activated 1-carbon units. Sarcosinemia is a rare inherited metabolic condition associated with mental retardation. In the present study, we investigated the acute effect of sarcosine and/or creatine plus pyruvate on some parameters of oxidative stress and energy metabolism in cerebral cortex homogenates of 21-day-old Wistar rats. Acute administration of sarcosine induced oxidative stress and diminished the activities of adenylate kinase, GAPDH, complex IV, and mitochondrial and cytosolic creatine kinase. On the other hand, succinate dehydrogenase activity was enhanced in cerebral cortex of rats. Moreover, total sulfhydryl content was significantly diminished, while DCFH oxidation, TBARS content, and activities of SOD and GPx were significantly enhanced by acute administration of sarcosine. Co-administration of creatine plus pyruvate was effective in the prevention of alterations provoked by sarcosine administration on the oxidative stress and the enzymes of phosphoryltransfer network. These results indicate that acute administration of sarcosine may stimulate oxidative stress and alter the energy metabolism in cerebral cortex of rats. In case these effects also occur in humans, they may contribute, along with other mechanisms, to the neurological dysfunction of sarcosinemia, and creatine and pyruvate supplementation could be beneficial to the patients. [ABSTRACT FROM AUTHOR]

A series of novel spirooxindolopyrrolidine derivatives has been prepared via a three-component 1,3-dipolar cycloaddition reaction of 2-oxindoleazomethine ylides generated in situ from isatin and sarcosine or valine with ( E)-3-aryl-2-cyanoacrylamides or ( E)-3-aryl-2-(4-arylthiazol-2-yl)acrylonitriles as dipolarophiles. To rationalize the observed regio- and stereoselectivity, calculations of the geometrical structures of all possible conformers and charge distribution in the reacting systems were performed. [ABSTRACT FROM AUTHOR]

Conjugated unsaturated carbonyl compounds with weak CH or NH acidity were used in a three-component reaction with sarcosine and formaldehyde, forming (3+2) cycloaddition products in 32-73% yields. The conversion was estimated from NMR data and strongly depended on the acidity of dipolarophile and the steric accessibility of its double bond. [ABSTRACT FROM AUTHOR]

In the present study, we developed an acute chemically induced model of sarcosinemia in Wistar rats. Wistar rats of 7, 14 and 21 postpartum days received sarcosine intraperitoneally in doses of 0.5 mmol/Kg of body weight three time a day at intervals of 3 h. Control animals received saline solution (NaCl 0.85 g%) in the same volume (10 mL/Kg of body weight). The animals were killed after 30 min, 1, 2, 3 or 6 h after the last injection and the brain and the blood were collected for sarcosine measurement. The results showed that plasma and brain sarcosine concentrations achieved levels three to four times higher than the normal levels and decreased in a time-dependent way, achieving normal levels after 6 hours. Considering that experimental animal models are useful to investigate the pathophysiology of human disorders, our model of sarcosinemia may be useful for the research of the mechanisms of neurological dysfunction caused by high tissue sarcosine levels. [ABSTRACT FROM AUTHOR]

In this study, a simple method for analysis of nonderivatized sarcosine was developed by gas chromatography. It is based on solid-phase microextraction of sarcosine on a novel synthesized solid-phase microextraction (SPME) fiber. A monolithic SPME fiber was fabricated based on a molecularly imprinted polymer that could be coupled with gas chromatography for extraction and determination of sarcosine. Extraction time, pH, and ionic strength were investigated as important factors in the extraction procedure. The fabricated fiber was firm, inexpensive, stable, and selective, which are vital characteristics for SPME. The selectivity of the fabricated fiber in relation to analog compounds was also investigated. Under optimum conditions, the calibration curve was linear in the range of 1-100 mg L ( R = 0.987). High extraction efficiency for sarcosine was obtained with a detection limit of 0.37 mg L. The fabricated fiber was successfully applied for SPME of sarcosine from urine after its extraction, followed by gas chromatography flame ionization detector analysis. [ABSTRACT FROM AUTHOR]

The capability of corona discharge ion mobility spectrometry ( CD-IMS) for separation and quantification of sarcosine and L-alanine isomers has been evaluated for the first time. Although these two compounds have the same mass and m/z values in mass spectrometer, ion mobility spectrometry was able to separate and determine them. Variables including carrier gas flow rate, injection and cell temperatures were optimized. The reduced mobilities ( K) of sarcosine and L-alanine were 1.96 and 1.83, respectively, based on the reduced mobility of nicotinamide. At the optimized conditions the detection limit of sarcosine and L-alanine were 0.7 and 0.9 μg/mL, respectively. The relative standard deviation ( RSD) was found to be 6%. Furthermore, a sample injection port of a gas chromatograph was also modified to introduce solvent-free samples into the IMS. [ABSTRACT FROM AUTHOR]

New water-soluble heteroligand complexes of 2-methyl-4-oxo-4 H-pyran-3-olatoneodymium(III) with aliphatic amino acids (glycine, N-methylglycine, and alanine) have been prepared. Within the biological 'transparency window' (700-900 nm) of their electronic absorption spectra, narrow bands of Nd are found: F ← I; F ← I; F ← I (750, 810, and 880 nm). Such complexes can be used as markers for biological tissues visualization. [ABSTRACT FROM AUTHOR]

A comparative study of the synthesis of novel spiro-oxindolo(pyrrolizidine/pyrrolidine) ring systems by the cycloaddition reaction of azomethine ylides generated by a decarboxylative route from sarcosine/proline and isatin with dibenzylideneacetone using various conditions is described. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Sarcosine, an isomer of l-alanine, has been recently proposed as a potential biomarker for prostate cancer risk and aggressiveness, while some studies debated its importance. As both sarcosine and l-alanine are present in human urine, it is a great challenge to separate and accurately quantify these isobaric (i.e., same m/z) compounds by chromatographic separation and mass spectrometric detection. In this study, we developed a novel 1,3-dipolar cycloaddition derivatization method that resolves sarcosine from l-alanine and allows accurate quantification of sarcosine in human urine by gas chromatography-mass spectrometry (GC-MS). This novel derivatization approach was specific to sarcosine only, while the common silylanization method resulted in overlapped derivates of both sarcosine and l-alanine. The derivatization conditions, including reagent amount, reaction temperature and time, were optimized. The method developed here has excellent precision (relative standard deviation <4.7 %, n = 5), good linearity (slope = 0.2408; r = 0.9996, 0.1-100 μg mL), and a low limit of detection in human urine (0.15 ng mL). Application of this analytical method to urine samples spiked with standard sarcosine indicates that it is a robust and powerful alternative for resolving and quantifying sarcosine from l-alanine isomer in human urine by GC-MS. [ABSTRACT FROM AUTHOR]

Since sarcosine and d,l-alanine co-elute on reversed-phase high-performance liquid chromatography (HPLC) columns and the tandem mass spectrometer cannot differentiate them due to equivalent parent and fragment ions, derivatization is often required for analysis of sarcosine in LC/MS systems. This study offers an alternative to derivatization by employing partial elimination of sarcosine by enzymatic oxidation. The decrease in apparent concentration from the traditionally merged sarcosine-alanine peak associated with the enzymatic elimination has been shown to be proportional to the total sarcosine present ( R = 0.9999), allowing for determinations of urinary sarcosine. Sarcosine oxidase was shown to eliminate only sarcosine in the presence of d, l-alanine, and was consequently used as the selective enzyme. This newly developed technique has a method detection limit of 1 μg/L (parts per billion) with a linear range of 3 ppb-1 mg/L (parts per million) in urine matrices. The method was further validated through spiked recoveries of real urine samples, as well as the analysis of 35 real urine samples. The average recoveries for low, middle, and high sarcosine concentration spikes were 111.7, 90.8, and 90.1 %, respectively. In conclusion, this simple enzymatic approach coupled with HPLC/MS/MS is able to resolve sarcosine from d,l-alanine leading to underivatized quantification of sarcosine. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Peroxidase-catalysed reactions are used in a wide variety of analytical applications, most of them based on the final quantification of hydrogen peroxide. Clinical tests for glucose, cholesterol, creatine, creatinine or uric acid in blood or urine and enzyme-linked immunosorbent assays for pesticides, hepatitis or acquired immune deficiency syndrome are good examples of such applications. The most widely used and commercially available peroxidase for biotechnological processes and analytical applications is horseradish peroxidase followed, although in much lower proportion, by soybean peroxidase. The high commercial interest in peroxidases has led to the search for new sources of these enzymes. This work describes the analytical use of lentil plant peroxidase (LPP), which is a new peroxidase extracted from lentil plants ( Lens culinaris Medikus); an abundant post-harvest agricultural waste in the area of Castilla y León (Spain). A procedure for the quantification of hydrogen peroxide in urine is first proposed using crude extract of lentil plant instead of the purified enzyme. This procedure is then applied to the determination of sarcosine; a natural amino acid that has attracted considerable interest in clinical diagnostics since urinary sarcosine was proposed and later questioned as a biomarker for prostate cancer. Under the action of sarcosine oxidase, sarcosine is oxidized by molecular oxygen to give glycine, formaldehyde and hydrogen peroxide that is quantified according to the previously proposed procedure. The limit of detection for both hydrogen peroxide and sarcosine is around 5 × 10 M. In the determination of sarcosine, the high selectivity of the overall enzymatic reaction, the simple sample treatment and instrumentation, the high-sample throughput and the use of LPP in the plant extract instead of the purified enzyme provide a rapid and inexpensive procedure with characteristics very suitable for routine analysis in a clinical laboratory. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

recent study showed that sarcosine may be potentially useful for the diagnosis and prognosis of prostate cancer (PCa). The aim of this study was to validate diagnostic value of sarcosine for PCa, to evaluate urine metabolomic profiles in patients with PCa in comparison of non-cancerous control, and to further explore the other potential metabolic biomarkers for PCa. Isotope dilution gas chromatography/mass spectrometry (ID GC/MS) metabolomic approach was applied to evaluate sarcosine using [methyl-D]-sarcosine as an internal standard. Microwave-assisted derivatization (MAD) together with GC/MS was utilized to obtain the urinary metabolomic information in 20 PCa patients compared with eight patients with benign prostate hypertrophy and 20 healthy men. Acquired metabolomic data were analyzed using a two-sample t test. Diagnostic models for PCa were constructed using principal component analysis and were assessed with receiver-operating characteristic curves. Results showed that the urinary sarcosine level has no statistical difference between the PCa group and the control group. In addition, nine metabolomic markers between the PCa group and the healthy male group were selected, which constructed a diagnostic model with a high area under the curve value of 0.9425. We conclude that although urinary sarcosine value has limited potential in the diagnostic algorithm of PCa, urinary metabolomic panel based on GC/MS assay following MAD may potentially become a diagnostic tool for PCa. [ABSTRACT FROM AUTHOR]

Sarcosine is an amino acid derivative of N-methylglycine and is involved in the amino acid metabolism and methylation processes that are enriched during prostate cancer progression. It could also serve as a new target to be measured during therapeutic interventions and help in the identification of aggressive tumors for radical treatment. In this study, we present a new urine test that can help early diagnosis of prostate cancer. The method for the quantification of sarcosine in urine consists of a solid-phase microextraction (SPME) step followed by gas chromatography-triple quadrupole mass spectrometry analysis. We used a preliminary derivatization step with ethyl chloroformate/ethanol and the corresponding ester was then extracted by SPME in immersion mode. Several fibers were evaluated and the optimization of the parameters affecting the SPME process was carried out using an experimental design. The optimal values were 20 min extraction time, 10% NaCl, and 270°C using a divinylbenzene/Carboxen/polydimethylsiloxane fiber. The triple quadrupole analyzer acquired data in selected reaction monitoring mode, allowing us to obtain reconstructed chromatograms with well-defined chromatographic peaks. The accuracy and precision of this method were evaluated at concentrations of 70, 250, and 800 ng/ml and were found to be acceptable. Very satisfactory values (0.10 and 0.16 ng/ml, respectively) were also achieved for the limit of detection and the limit of quantification. The proposed protocol represents a rapid, simple, selective, and sensitive tool to quantify sarcosine in urine samples for prostate cancer diagnosis and for a screening test. [ABSTRACT FROM AUTHOR]

Increasing evidence suggests that Human epidermal growth factor receptor 2 (HER2/neu) is involved in progression of prostate cancer. Recently, sarcosine was reported to be highly increased during prostate cancer progression, and exogenous sarcosine induces an invasive phenotype in benign prostate epithelial cells. The aim of this work was to investigate the effect of sarcosine on HER2/neu expression in prostate cancer cell lines LNCaP (androgen dependent), PC-3 and DU145 (both androgen independent). Relative amounts of HER2/neu and androgen receptor (AR) transcripts were determined using RT-qPCR. Total expression of HER2/neu was confirmed by Western blot (WB). HER2/neu protein on the surface of living LNCaP cells was visualized by confocal microscopy using a HER2/neu-specific fluorescent probe. Exposure of LNCaP cells to 50 μM sarcosine for 24 h resulted in a 58% increase of the HER2/neu mRNA level ( P < 0.001) indicating that sarcosine effects HER2/neu expression on the level of transcription. Control experiments with alanine, an isomer of sarcosine, showed no significant effect on HER2/neu transcription. The upregulation of HER2/neu mRNA preceded the corresponding increment of the protein level after the 48-h exposure to sarcosine as shown by WB and confocal microscopy. Interestingly, sarcosine had no effect on the activated (phosphorylated) form of HER2/neu. No significant change in AR expression was observed after exposure to sarcosine. This is the first report indicating that sarcosine is involved in the regulation of the oncoprotein HER2/neu. Thus, sarcosine may induce prostate cancer progression by increased HER2/neu expression. However, detailed information on cellular mechanisms remains to be elucidated. [ABSTRACT FROM AUTHOR]

Conditions are selected for the analytical separation of ( N-phosphonomethyl glycine), products of its microbiological conversion, glutamic acid, and alanine as dansyl derivatives using reversed-phase HPLC: column (250 × 4.6 mm) ReproSil-PAH EPA; mobile phase, methanol + 20 mM CHCOONa (pH 5.1) (20: 80); rate of mobile phase, 1 mL/min; working detector wavelength, 330 nm. The duration of separation is 35 min. The lower limits of the analytical range (in ng) for dansyl derivatives are as follows: glyphosate, 8.2; aminomethyl phosphonic acid, 24.2; glutamic acid, 9.4; alanine, 12.6: glycine, 17.7; and sarcosine, 19.3. The TLC study of dansyl derivatives of amino acids was performed on sorbfil plates PTSH-P-V using two-dimensional chromatography in the systems ethyl acetate-isopropanol-24% aqueous ammonia (45: 35: 20) in the first direction and chloroform-methanol-acetic acid (25: 5: 1) in the second one. For determining phosphonic acids (glyphosate and aminomethyl phosphonic acid), a version of one-dimensional chromatography with the sequential use of two systems, chloroform-methanol-acetic acid (25: 5: 0.2) and ethanol-24% aqueous ammonia (7: 3), was proposed. [ABSTRACT FROM AUTHOR]

An amperometric biosensor for the determination of creatine was developed. The carbon rod electrode surface was coated with sarcosine oxidase (SOX) and creatine amidinohydrolase by cross-linking under glutaraldehyde vapour. The SOX from Arthrobacter sp. 1–1 N was purified and previously used for creation of a creatine biosensor. The natural SOX electron acceptor, oxygen, was replaced by an $$ {{\left[ {Fe{\left( {CN} \right)}_{6} } \right]}^{{3 - }} } \mathord{\left/ {\vphantom {{{\left[ {Fe{\left( {CN} \right)}_{6} } \right]}^{{3 - }} } {{\left[ {Fe{\left( {CN} \right)}_{6} } \right]}}}} \right. \kern-\nulldelimiterspace} {{\left[ {Fe{\left( {CN} \right)}_{6} } \right]}}^{{4 - }} $$ redox mediating system, which allowed amperometric detection of an analytical signal at +400-mV potential. The response time of the biosensor was less than 1 min. The biosensor showed a linear dependence of the signal vs. creatine concentration at physiological creatine concentration levels. The optimal pH in 0.1 M tris(hydroxymethyl)aminomethane (Tris)–HCl buffer was found to be at pH 8.0. The half-life of the biosensor was 8 days in 0.1 M Tris–HCl buffer (pH 8.0) at 20 °C. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The primary structures of the C and D subunits of sarcosine oxidase from Corynebacterium sp. U-96 were determined by sequencing the peptide fragments derived from their enzymatic digestions. The C and D subunits were shown to be composed of 199 and 92 residues, respectively. Each amino acid sequence showed a high homology with the sequence of the corresponding subunit from Corynebacterium sp. P-1. However, there were some differences between these two species, that is, four N-terminal residues were truncated in the C subunit, but six C-terminal residues were truncated in the D subunit. The D subunit contained three cysteine residues, but no disulfide bonds are in the subunit. Overall sequences of both subunit showed no homology with any other protein in the data base. [ABSTRACT FROM AUTHOR]

Synthetic protocols are presented both for D-PheSar and the corresponding cyclised diketopiperazine, prepared from N-t-butoxycarbonylprotected D-PheSar. Deprotection conditions could be manipulated to yield either D-Phenylalanylsarcosine or (R)-1-methyl-3-(phenylmethyl)-2,5-piperazinedione. Molecular modelling revealed several low energy conformers which contained a Z-peptide bond and which were readily amenable to cyclisation. Cyclisation was found by HPLC to be fastest in strongly acidic conditions. [ABSTRACT FROM AUTHOR]

Sarcosine reductase is the only reductase system present in Tissierella creatinophila when grown on creatinine plus formate. The acetyl-phosphate-forming component protein C was purified to homogeneity. SDS-PAGE of the purified protein revealed two protein bands with apparent mol. masses of 62 and 50 kDa. The N-terminal amino acid sequence of the two subunits was determined. Antibodies raised against each of the subunits of protein C from Eubacterium acidaminophilum cross-reacted with the corresponding protein present in T. creatinophila, Clostridium litorale and Clostridium sporogenes. The arsenate-dependent hydrolysis of acetyl phosphate catalyzed by protein C was partly inhibited by antibodies directed against the large subunit. Antibodies raised against the small subunit were twice as effective, which indicates that this subunit is the primary site of acetyl transfer from acetyl phosphate. The protein A component of the sarcosine reductase of T. creatinophila was purified to homogeneity by cochromatography with thioredoxin reductase on DEAE-Sephacel, hydroxylapatite, Q-Sepharose, and Sephacryl 100-HR. Protein A had an apparent mol. mass of 21 kDa. Its N-terminal amino acid sequence showed high similarities to that of other proteins A. Initial steps for the purification and preliminary characterization of the sarcosine-specific, substrate-binding protein Bsarcosine component of T. creatinophila indicated the involvement of a 50-kDa protein. [ABSTRACT FROM AUTHOR]

Alcaligenes spec. strain GL (IMET 11314) is able to grow on glyphosate (N-[phosphonomethyl]glycine) and other phosphonates as sole source of phosphorus. Degradation of glyphosate to inorganic phosphate and sarcosine by this strain is subject to several regulatory principles. While uptake and dephosphonation of glyphosate are regulated by P starvation, the intensity of glyphosate degradation is also controlled by the cellular ability to utilize the C-skeleton derived from glyphosate. Depending on the external concentration of glyphosate, the liberated sarcosine is differentially metabolised. Utilization of the sarcosine moiety and complete incorporation of 3-[C]-label of glyphosate into cellular material occur only in cultures adapted to higher concentrations (5 mM) of the herbicide. At low concentrations of glyphosate (1 mM) only the P required by the growing cultures is utilized but not the sarcosine. Initially high rates of glyphosate uptake obtained after P-starvation decrease in the presence of low glyphosate concentrations. It is suggested that uptake and metabolism of glyphosate are connected with the expression of the sarcosine metabolizing capacity of the Alcaligenes cells. [ABSTRACT FROM AUTHOR]

The article presents a study of properties of N-bis(2-ethylhexyloxy)phosphorylmethyl derivatives for sarcosine (I) and beta-alanine (II) as new agents for liquid extraction of Cu(II), Fe(III), Ni(II), and ?o(II) ions from nitric acid aqueous solutions. Results of the study demonstrated the increasing degree of the metal ions extraction with increasing pH of the aqueous phase, the extracting efficiency decreasing in the Cu(II) > Fe(III) > Ni(II) = ?o(II) series.

A letter to the editor is presented regarding the preparation and membrane transport properties of sarcosine's phosphorylated derivatives.