Omic Studies on In Vitro Cystinosis Model: siRNA-Mediated CTNS Gene Silencing in HK-2 Cells.

Cystinosis is an autosomal recessive disease caused by mutations in the CTNS gene encoding a protein called cystinosine, which is a lysosomal cystine transporter. Disease-causing mutations lead to accumulation of cystine crystals in the lysosomes, thereby causing dysfunction of vital organs. Determination of the increased leukocyte cystine level is one of the most used methods for diagnosis. However, this method is expensive, difficult to perform, and may yield different results in different laboratories. In this study, a disease model was created with CTNS gene-silenced HK2 cells, which can mimic cystinosis in cell culture, and multiomics methods (ie, proteomics, metabolomics, and fluxomics) were implemented at this cell culture to investigate new biomarkers for the diagnosis. CTNS-silenced cell line exhibited distinct metabolic profiles compared with the control cell line. Pathway analysis highlighted significant alterations in various metabolic pathways, including alanine, aspartate, and glutamate metabolism; glutathione metabolism; aminoacyl-tRNA biosynthesis; arginine and proline metabolism; beta-alanine metabolism; ascorbate and aldarate metabolism; and histidine metabolism upon CTNS silencing. Fluxomics analysis revealed increased cycle rates of Krebs cycle intermediates such as fumarate, malate, and citrate, accompanied by enhanced activation of inorganic phosphate and ATP production. Furthermore, proteomic analysis unveiled differential expression levels of key proteins involved in crucial cellular processes. Notably, peptidyl-prolyl cis-trans isomerase A, translation elongation factor 1-beta (EF-1beta), and 60S acidic ribosomal protein decreased in CTNS-silenced cells. Additionally, levels of P0 and tubulin α-1A chain were reduced, whereas levels of 40S ribosomal protein S8 and Midasin increased. Overall, our study, through the utilization of an in vitro cystinosis model and comprehensive multiomics approach, led to the way toward the identification of potential new biomarkers while offering valuable insights into the pathogenesis of cystinosis.

Molecularly imprinted electrochemical sensor for the selective and sensitive determination of octreotide in cancer patient plasma sample.

In this study, a molecularly imprinted polymer film (P (ANI)@MIP) on the electrode surface was fabricated using aniline as a functional monomer and octreotide (OC) as a template molecule. The developed P (ANI)@MIP was electrochemically electropolymerized on a glassy carbon electrode (GCE) surface. Each step of MIP production was evaluated by viewing the [Fe (CN)6]3-/4- signal obtained using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The P (ANI)@MIP film layer was studied with a scanning electron microscope (SEM), Raman, and contact angle measurements. The parameters consisting of monomer, template ratio, cycle number, removal solution, removal time, and rebinding time were optimized to obtain the best electrochemical sensor. The developed method was validated in line with ICH guidelines. The linear range, LOD, and LOQ were found as 10-80 fM, 0.801 fM, and 2.670 fM, respectively. The selectivity of the method was tested with the response of somatostatin and lanreotide from the same growth hormone family by comparing the OC response. The developed P (ANI)@MIP/GCE sensor is the first reported method for electrochemical analysis of OC. The P (ANI)@MIP/GCE sensor exhibited high sensitivity and selectivity for OC. The novel MIP sensor was used to determine OC in cancer patient plasma samples. The concentration of OC in cancer patients varied between 8.98 ng/mL and 10.10 ng/mL.

Metabolomic Analyses to Identify Candidate Biomarkers of Cystinosis.

Cystinosis is a rare, devastating hereditary disease secondary to recessive CTNS gene mutations. The most commonly used diagnostic method is confirmation of an elevated leukocyte cystine level; however, this method is expensive and difficult to perform. This study aimed to identify candidate biomarkers for the diagnosis and follow-up of cystinosis based on multiomics studies. The study included three groups: newly-diagnosed cystinosis patients (patient group, n = 14); cystinosis patients under treatment (treatment group, n = 19); and healthy controls (control group, n = 30). Plasma metabolomics analysis identified 10 metabolites as candidate biomarkers that differed between the patient and control groups [L-serine, taurine, lyxose, 4-trimethylammoniobutanoic acid, orotic acid, glutathione, PE(O-18:1(9Z)/0:0), 2-hydroxyphenyl acetic acid, acetyl-N-formil-5-metoxikinuramine, 3-indoxyl sulphate]. As compared to the healthy control group, in the treatment group, hypotaurine, phosphatidylethanolamine, N-acetyl-d-mannosamine, 3-indolacetic acid, p-cresol, phenylethylamine, 5-aminovaleric acid, glycine, creatinine, and saccharic acid levels were significantly higher, and the metabolites quinic acid, capric acid, lenticin, xanthotoxin, glucose-6-phosphate, taurine, uric acid, glyceric acid, alpha-D-glucosamine phosphate, and serine levels were significantly lower. Urinary metabolomic analysis clearly differentiated the patient group from the control group by means of higher allo-inositol, talose, glucose, 2-hydroxybutiric acid, cystine, pyruvic acid, valine, and phenylalanine levels, and lower metabolite (N-acetyl-L-glutamic acid, 3-aminopropionitrile, ribitol, hydroquinone, glucuronic acid, 3-phosphoglycerate, xanthine, creatinine, and 5-aminovaleric acid) levels in the patient group. Urine metabolites were also found to be significantly different in the treatment group than in the control group. Thus, this study identified candidate biomarkers that could be used for the diagnosis and follow-up of cystinosis.

GC-MS Based Metabolomics Analysis to Evaluate Short-Term Effect of Tumor Removal on Patients with Early-Stage Breast Cancer.

In this study, it was aimed to demonstrate the short-term effect of breast cancer surgery and tumor removal on the metabolomic profiles of patients with early-stage breast cancer. This cohort consisted of 18 early-stage breast carcinoma patients who had breast cancer surgery to remove tumor and surrounding tissues. The blood samples obtained preoperatively and 24 h after surgery were used in this investigation. Gas chromatography-mass spectrometry (GC-MS) based metabolomic analysis was performed to determine the metabolites. The GC-MS-based metabolomics profile enabled the identification of 162 metabolites in the plasma samples. Postoperatively, glyceric acid, phosphoric acid, O-phosphocolamine, 2-hydroxyethyliminodiacetic acid, N-acetyl-D-mannosamine, N-acetyl-5-hydroxytryptamine, methyl stearate, methyl oleate, iminodiacetic acid, glycerol 1-phosphate, ß-glycerol phosphate and aspartic acid were found to be significantly increased (P < 0.05 for all), whereas saccharic acid, leucrose, gluconic acid, citramalic acid and acetol were significantly decreased (P < 0.05 for all). Breast cancer surgery and tumor removal has an impact on the metabolomic profiles of patients with early-stage breast cancer. These findings can be used for understanding the pathogenesis of breast cancer biology and screening the success of the surgery.

Separation of the enantiomers of underivatized amino acids by using serially connected dual column high-performance liquid chromatography-tandem mass spectrometry.

In this article, a serially connected dual column liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is described for the simultaneous separation and enantioseparation of proteinogenic amino acids. For this purpose, different achiral and chiral stationary phases (CSP) and mobile phase compositions have been tested. As a result of the optimization studies, the best enatioseparation for amino acids were achieved with a combination of zwitterionic and crown ether stationary phases using a gradient of two mobile phases: A (water:TFA 99.5:0.5, % v/v) and B (acetonitrile:ethanol:TFA 85:15:0.5, % v/v/v). The developed method provided simultaneous enantioseparation of all proteinogenic amino acids under this study including isomeric and isobaric ones except for proline. The method was successfully applied to human lung adenocarcinoma cells (A549) and healthy human lung epithelial cells (BEAS-2B) cultivated with d-amino acid containing cocktails in order to evaluate d-amino acids transfer rate in normal and cancer lines. Thed/l amino acid ratios were different in cancer and normal cell lines cultivated as mentioned above for aspartic acid, cysteine, methionine, phenylalanine, and serine.

Liquid biopsy markers for early diagnosis of brain metastasis patients with breast cancer by metabolomics.

Introduction: Breast cancer is the most common cancer in women and is the second most common cause of cancer related mortality. Metabolomics, the identification of small metabolites, is a technique for determining the amount of these metabolites. Objectives: This study aimed to identify markers for the early diagnosis of brain metastasis by metabolomic methods in breast cancer patients. Methods: A total of 88 breast cancer patients with distant metastases were included in the study. The patients were divided into two groups according to their metastasis status: patients with brain metastases and distant metastases without any brain metastases. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-qTOF-MS) and gas chromatography-mass spectrometry (GC-MS) analysis methods were used for metabolomic analyses. Results: 33 of them, 88 patients had brain metastasis, and 55 patients had distant metastases without brain metastasis. A total of 72 and 35 metabolites were identified by the GC-MS and LC-qTOF-MS analysis, respectively. 47 of them were found to be significantly different in patients with brain metastasis. The pathway analysis, performed with significantly altered metabolites, showed that aminoacyl tRNA biosynthesis, valine, leucine and isoleucine biosynthesis, alanine, aspartate, and glutamate metabolism, arginine biosynthesis, glycine, serine, and threonine metabolism pathways significantly altered in patients with brain metastasis. Predictive accuracies for have identifying the brain metastasis were performed with receiver operating characteristic (ROC) analysis, and the model with fifteen metabolites has 96.9% accuracy. Conclusions: While these results should be supported by prospective studies, these data are promising for early detection of brain metastasis with markers in liquid biopsy samples.

A stability indicating RP-HPLC method for determination of the COVID-19 drug molnupiravir applied using nanoformulations in permeability studies.

Antiviral drugs have gained much more attention in recent years due to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection and many drug candidates are currently under investigation in order to end pandemic. Molnupiravir, a prodrug of the synthetic nucleoside derivative N4-hydroxycytidine, is one of the promising candidates for SARS-CoV-2 treatment. In this study, a RP-HPLC method was developed for the determination of Molnupiravir and applied for in vitro permeability studies of self-emulsifying drug delivery system (SEDDS) formulations using Caco-2 cell line. Discovery® HS C18 Column (75 ×4.6 mm, 3 µm) was used at 30 °C. Isocratic elution was performed with ACN:water (20:80 v/v) mixture. The flow rate was 0.5 mL/min and UV detection was at 240 nm. Molnupiravir eluted within 5 min. Molnupiravir was exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions. Peak homogeneity data of Molnupiravir in the stressed samples peak obtained using photodiode array detector, in the stressed sample chromatograms, demonstrated the specificity of the method for their estimation in presence of degradants. The developed method was validated according to the International Council for Harmonisation (ICH) guidelines and found to be linear within the range 0.1-60.0 µg/mL. The method was simple, rapid, selective, sensitive, accurate, precise, robust and rugged. Thus, it was applied successfully for permeability quantitation of Molnupiravir in nanoformulations. The apparent permeability of Molnupiravir in SEDDS formulations, which have droplet size under 350 nm, was calculated as 3.20 ± 0.44 × 10-6 cm/s.

The effects of systemic and local fatty acid amide hydrolase and monoacylglycerol lipase inhibitor treatments on the metabolomic profile of lungs.

The contribution of the endocannabinoid system to both physiology and pathological processes in the respiratory system makes it a promising target for inflammatory airway diseases. Previously, we have shown that increasing the tissue endocannabinoid levels by fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) inhibitors can prevent airway inflammation and hyperreactivity. In this study, the changes in the levels of major metabolites of endocannabinoids by systemic and local FAAH or MAGL inhibitor treatments were evaluated. Mice were treated with either the FAAH inhibitor URB597 or the MAGL inhibitor JZL184 by local (intranasal) or systemic (intraperitoneal) application. Bronchoalveolar lavage (BAL) fluids and lungs were isolated afterward in order to perform histopathological and metabolomic analyses. There were no significant histopathological changes in the lungs and neutrophil, and macrophage and lymphocyte numbers in BAL fluid were not altered after local and systemic treatments. However, GC-MS-based metabolomics profile allowed us to identify 102 metabolites in lung samples, among which levels of 75 metabolites were significantly different from the control. The metabolites whose levels were changed by treatments were mostly related to the endocannabinoid system and energy metabolism. Therefore, these changes may contribute to the anti-inflammatory effects of URB597 and JZL184 treatments in mice.

Integrative proteomics and metabolomics approach to elucidate the antimicrobial effect of simvastatin on Escherichia coli.

Globally, simvastatin is one of the most commonly used statin drugs. Its antimicrobial properties have been investigated against various pathogens. However, its effect on biological processes in bacteria has been unclear. This study focused on altered biological and metabolic processes at protein and metabolite levels induced by simvastatin. MS-based proteomics and metabolomics were used to investigate the altered proteins and metabolites between experimental groups. Proteomics results showed that simvastatin induced various antimicrobial targets such as chaperon protein DnaK and cell division protein FtsZ. Metabolomics results revealed phenotypic changes in cells under simvastatin stress. Integrated proteomics and metabolomics result indicated that various metabolic processes were altered to adapt to stress conditions. Energy metabolism (glycolysis, tricarboxylic acid cycle, etc.), amino acid synthesis and ribosomal proteins, and purine and pyrimidine synthesis were induced by the effect of simvastatin. This study will contribute to the understanding of antimicrobial properties of statin drugs.

Determination and validation of aprepitant in rat plasma using LC-MS/MS.

Aim: The assessment of efficacy should be paralleled with extensive pharmacokinetic parameters, and a valid bioanalytical method is a pre-condition for accurate plasma concentration. Materials & methods: A simple, specific, rapid and sensitive LC-MS/MS method has been developed for quantitative analysis of aprepitant in rat plasma. A C18 column was used as stationary phase and the mobile phase consisted of a mixture of formic acid in water and formic acid in acetonitrile. Quantification was performed using multiple reaction monitoring mode. Results: The selectivity, linearity, accuracy, precision, robustness and ruggedness of the method were evaluated in accordance with bioanalytical method validation guideline of ICH and all results were within the acceptable range. Conclusion: The validated LC-MS/MS method was found to be useful for the quantitative analysis of aprepitant in rat plasma samples.

Gas chromatography-mass spectrometry based 18O stable isotope labeling of Krebs cycle intermediates.

New technologies permit determining metabolomic profiles of human diseases by fingerprinting metabolites levels. However, to fully understand metabolomic phenotypes, metabolite levels and turnover rates are necessary to know. Krebs cycle is the major hub of energy metabolism and cell signaling. Traditionally, 13C stable isotope labeled substrates were used to track the carbon turnover rates in Krebs cycle metabolites. In this study, for the first time we introduce H2[18O] based stable isotope marker that permit tracking oxygen exchange rates in separate segments of Krebs cycle. The chromatographic and non-chromatographic parameters were systematically tested on the effect of labeling ratio of Krebs cycle mediators to increase selectivity and sensitivity of the method. We have developed a rapid, precise, and robust GC-MS method for determining the percentage of 18O incorporation to Krebs cycle metabolites. The developed method was applied to track the cancer-induced shift in the Krebs cycle dynamics of Caco-2 cells as compared to the control FHC cells revealing Warburg effects in Caco-2 cells. We demonstrate that unique information could be obtained using this newly developed 18O-labeling analytical technology by following the oxygen exchange rates of Krebs cycle metabolites. Thus, 18O-labeling of Krebs cycle metabolites expands the arsenal of techniques for monitoring the dynamics of cellular metabolism. Moreover, the developed method will allow to apply the 18O-labeling technique to numerous other metabolic pathways where oxygen exchange with water takes place.

Characterization of human bone marrow niches with metabolome and transcriptome profiling.

Bone marrow (BM) niches are special microenvironments that work in harmony with each other for the regulation and maintenance of hematopoiesis. Niche investigations have thus far been limited to various model organisms and animal studies; therefore, little is known about different niches in healthy humans. In this study, a special harvesting method for the collection of BM from two different anatomical regions in the iliac crest of humans was used to investigate the presence of different niches in BM. Additionally, metabolomic and transcriptomic profiles were compiled using comparative 'omics' technologies, and the main cellular pathways and corresponding transcripts and metabolites were identified. As a result, we found that the energy metabolism between the regions was different. This study provides basic broad data for regenerative medicine in terms of the design of the appropriate microenvironment for in vitro hematopoietic niche modeling, and identifies the normal reference values that can be compared in hematological disease.

Integration of GC-MS and LC-MS for untargeted metabolomics profiling.

Recently, metabolomics analyses have become increasingly common in the general scientific community as it is applied in several researches relating to diseases diagnosis. Identification and quantification of small molecules belonging to metabolism in biological systems have an important role in diagnosis of diseases. The combination of chromatography with mass spectrometry is used for the accurate and reproducible analysis of hundreds to thousands of metabolites in biological fluids or tissue samples. The number of metabolites that can be identified in biological fluids or tissue varies according to the gas (GC) or liquid (LC) chromatographic techniques used. The cover of these chromatographic techniques also differs from each other based on the metabolite group (polar, lipids, organic acid etc.). Consequently, some of the metabolites can only be analyzed using either GC or LC. However, more than one metabolite or metabolite group may be found altered in a particular disease. Thus, in order to find these alterations, metabolomics analyses that cover a wide range of metabolite groups are usually applied. In this regard, GC-MS and LC-MS techniques are mostly used together to identify completely all the altered metabolites during disease diagnosis. Using these combined techniques also allows identification of metabolite(s) with significantly altered phenotype. This review sheds light on metabolomics studies involving the simultaneous use of GC-MS and LC-MS. The review also discusses the coverage, sample preparation, data acquisition and data preprocessing for untargeted metabolomics studies. Moreover, the advantages and disadvantages of these methods were also evaluated. Finally, precautions and suggestions on how to perform metabolomics studies in an accurate, precise, complete and unbiased way were also outlined.

GC-MS analysis of seven metabolites for the screening of pregnant women with Down Syndrome fetuses.

Down Syndrome is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. Metabolomics is identification and quantification of small-molecule metabolites (molecular weight <1000 Da) in tissues, cells and physiological fluids within a certain period time. Metabolites are intermediate products of various types of biochemical reactions that participate in bonding metabolic pathways. In this study, metabolites such as 2-Hydroxybutyric acid, 3-Hydroxybutyric acid, ß-Hydroxyisovaleric acid, Uracil, Glutamic acid, Maltose and Melezitose were chosen as the possible determinants/markers for the prenatal screening of Down Syndrome. Quantitative analysis of the metabolites conducted by GCMS method using 5 % phenyl / 95 % dimethylpolysiloxane (30 m ×0.25 mm, 0.25 µm film thickness) capillary column. The oven temperature was held constant at 60 °C for 1 min and ramped at 10 °C /min to 200 °C then ramped at 30 °C/min to 320 °C and hold for 6 min before cool-down, as helium mobile phase and flow rate of 2.8 mL/min and adding Myristic acid-d27 as an internal standard. Our method was validated by parameters of system suitability, stability, linearity, sensitivity, accuracy, precision, selectivity, robustness and ruggedness. The developed and validated method was applied to plasma samples taken from pregnant women with Down Syndrome (study group) and euploid fetuses (healthy group). The levels of these seven metabolites are statistically different (p < 0.05 for all) between the groups. It can be concluded that these relevant metabolites might be used for the prenatal screening of Down Syndrome.

GC-MS Based Metabolic Profiling of Parkinson's Disease with Glutathione S-transferase M1 and T1 Polymorphism in Tunisian Patients.

AIM AND OBJECTIVE: Parkinson's disease (PD) is the second most common neurodegenerative disease. It is a multifactorial disorder (caused by aging, environmental, and genetic factors). Metabolomics can help explore the biomarker profiles for aging. Recent studies showed an association between the glutathione S-transferases (GSTs) polymorphisms and PD risk. The purpose of this study was to evaluate the association of this genetic polymorphism and the metabolomic profile in PD Tunisian patients, in order to identify effective biomarkers in the genetic differentiation. MATERIALS AND METHODS: In this study, the metabolomic profile changes related to GSTs polymorphism were searched in 54 Tunisian PD patients treated with L-dopa, using a gas chromatography-mass spectrometry (GC-MS) technique. RESULTS: The study results showed that mannose, methyl stearate, and three other unknown metabolites, increased in patients with GSTM1 positive genotype, while glycolic acid, porphine, monomethyl phosphate, fumaric acid, and three other unknown metabolites decreased in patients with GSTM1 positive genotype. Subsequently, the levels of glycolic acid, erythronic acid, lactic acid, citric acid, fructose, stearic acid, 2-amino-2-methyl-1,3-propanediol and three other unknown metabolites increased in patients with GSTM1 positive genotype, while the levels of proline, valine and two unknown metabolites decreased with GSTT1 positive genotype. CONCLUSION: All these altered metabolites are related to energy metabolism and it can be concluded that GSTs polymorphism based the shifting in energy metabolism and led to oxidative stress.

Metabolic infrastructure of pregnant women with methylenetetrahydrofolate reductase polymorphisms: A metabolomic analysis.

The aim of this study was to demonstrate the altered metabolic infrastructure of pregnant women with methylenetetrahydrofolate reductase (MTHFR) polymorphisms at first trimester and during delivery. Eight singleton pregnant women with MTHFR polymorphisms were compared with 10 normal pregnant women. Maternal blood samples were obtained twice during their pregnancy period (between the 11th and 14th gestational weeks and during delivery). Metabolomic analysis was performed using GC-MS. The GC-MS based metabolomic profile helped identify 95 metabolites in the plasma samples. In the MTHFR group, the levels of 1-monohexadecanoylglycerol, pyrophosphate, benzoin, and linoleic acid significantly decreased (P ˂ 0.05 for all), whereas the levels of glyceric acid, l-tryptophan, l-alanine, l-proline, norvaline, l-threonine, and myo-inositol significantly increased (P ˂ 0.01 for the first two metabolites, P ˂ 0.05 for the others) at 11-14 gestational weeks. Conversely, the levels of benzoin, 1-monohexadecanoylglycerol, pyruvic acid, l-proline, phosphoric acid, epsilon-caprolactam, and pipecolic acid significantly decreased in the MTHFR group, whereas metabolites such as hexadecanoic acid and 2-hydroxybutyric acid increased significantly in the study group during delivery. An impaired energy metabolism pathway, vitamin B complex disorders, tendency for metabolic acidosis (oxidative stress), and the need for cell/tissue support seem prevalent in pregnancies with MTHFR polymorphisms.

Metabolic Infrastructure of Pregnant Women With Trisomy 21 Fetuses; Metabolomic Analysis.

We aimed to configure impaired/altered metabolomic profiles of pregnant women carrying Down syndrome (DS) fetuses. The study involved 21 and 32 pregnant women with DS and euploid fetuses, respectively, as determined by prenatal screening and diagnosis as part of an antenatal care program. Metabolomic analyses were carried out using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-qTOF-MS) methods. A total of 95 metabolites were identified. GC-MS analysis indicated that levels of 2-hydroxybutyric acid, benzoic acid, nonanoic acid, 3-hydroxybutyric acid, and 2-ketoisocaproic acid were increased in the DS group, where beta-alanine, threonic acid, oxalic acid, alpha-tocopherol, uracil, 2-piperidone, and creatinine were decreased. However, LC-qTOF-MS analysis showed that lipid-related metabolites were decreased in women carrying DS fetuses, whereas creatine, N4-phosphoagmatine, citrate, 2,5-dioxopentanoate, 2-furoate, pyruvate, and fructose levels were increased. Pathway analysis was also performed using metabolites whose levels were significantly altered (p<0.05) between the groups, and the findings indicated that the biosynthesis pathways of aminoacyl-tRNA and "valine-leucine-isoleucine", and metabolism pathways of "glycine-serine-threonine", nitrogen, "alanine-aspartate-glutamate", propanoate, glycerophospholipid, cysteine, methionine, and phenylalanine were significantly altered. Our findings indicate a special type of metabolic status/syndrome in pregnant women with Down syndrome fetuses. It could be speculated that altered metabolic status might influence both gametogenesis and embryogenesis. Down syndrome is a complex genetic disorder that is important to detect prenatally, but may also be prevented by taking necessary precautions prior to pregnancy.

An LC-ESI-MS/MS method for the simultaneous determination of pronuciferine and roemerine in some Papaver species.

Papaver species, well known for their alkaloids, have been used for the treatment of several diseases, such as inflammation, diarrhea, depression, and sleep disorders in certain parts of Anatolia. In this study, four Papaver species (P. lacerum, P. syriacum, P. glaucum and P. rhoeas) were collected from different localities of Turkey. Methanolic extracts were prepared from the aerial parts of the plants. A rapid analytical method was developed for the simultaneously quantitative analysis of two alkaloids, pronuciferine and roemerine, using liquid chromatography tandem mass spectrometry. Multiple reaction monitoring in the positive ionization mode was used for detection. Pronuciferine and roemerine were analyzed on a C18 column (2.1 × 50 mm, 3 µm) with the mobile phase run in the gradient mode with 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile at a flow rate of 0.3 mL/min. The transitions 312.1→283.1 m/z and 280.0→249.0 m/z were used to monitor pronuciferine and roemerine, respectively. The assay was linear in the concentration range of 0.01 µg/mL to 1 µg/mL (r = 0.996 for roemerine, r = 0.998 for pronuciferine). The validation studies revealed that the method was linear, sensitive, accurate, precise, selective, repeatable, robust, and rugged. Finally, the developed method was applied to quantify pronuciferine and roemerine in the selected species. The amounts of pronuciferine and roemerine were respectively found as 8.5 to 48 µg/g and 4.4 to 43,000 µg/g.

Determination of Rivaroxaban in Human Plasma by Solid-Phase Extraction-High Performance Liquid Chromatography.

In this study, a solid-phase extraction (SPE)-high performance liquid chromatography (HPLC)-ultra violet (UV) method was developed for the determination of rivaroxaban (RIV), an oral anticoagulant drug, in human plasma samples. The concentration of RIV in plasma samples was increased 7.5 times and the interference coming from matrix components was avoided by using SPE. The extracted samples of RIV were analyzed by using an HPLC-UV method. RIV was approved in 2008 and many studies have been published in recent years in order to investigate its pharmacokinetic profile in various groups. In light of this information, it is clear that the RIV pharmacokinetic profile should be investigated in further studies; the HPLC-UV method presented in this study might be an easy method to apply, as it is a cheap and rapid alternative to HPLC-MS-MS for this purpose. A Phenomenex Luna 5-µm C18 100 Å LC column (250 × 4.6 mm) was used for the separation of RIV and prednisolone (internal standard). The total analysis time was <6 min. The method was validated according to the FDA guidelines and can be proposed for pharmacokinetic studies of RIV.

Maternal blood and amniotic fluid levels of moxifloxacin, levofloxacin and cefixime.

AIM: Moxifloxacin and levofloxacin are wide spectrum quinolones and cefixime is a third-generation cephalosporin with a wider spectrum of activity against gram-positive and gram-negative bacteria and anaerobics. Although they are widely used, little is known about the amniotic fluid levels of these antibiotics. The aim of the present investigation was to study and compare the maternal blood and amniotic fluid levels of these antibiotics in second trimester pregnancy. METHODS: To assess the amniotic fluid levels of these antibiotics, 10 pregnant women were given moxifloxacin, 10 were given levofloxacin and 6 were given cefixime orally 2 h before amniocentesis as a single dose for prophylaxis. During amniocentesis, an extra 2 mL amniotic fluid sample and 2 mL maternal venous blood were drawn. The levels of these agents in samples were analyzed using high performance liquid chromatography. RESULTS: The amniotic fluid levels of moxifloxacin and levofloxacin were 0.27 +/- 0.21 microg/mL and 0.60 +/- 0.41 microg/mL, respectively. The maternal blood levels were 3.53 +/- 0.65 microg/mL and 3.95 +/- 0.77 microg/mL in the moxifloxacin and levofloxacin groups, respectively. The maternal blood level of cefixime was 2.59 +/- 1.10 microg/mL and the amniotic fluid level was 0.85 +/- 0.42 microg/mL. The amniotic fluid passage rates were 7.83% for moxifloxacin, 15.67% for levofloxacin and 37.55% for cefixime. CONCLUSION: Of these three antibiotics, cefixime has the highest transplacental passage rate and, therefore, can be used as a therapeutic agent in infectious conditions in which membranes and the placenta are involved. Moxifloxacin and levofloxacin have low passage rates, which should be considered when using as a therapeutic agent.