Víctor González-Ruiz

University Foundation San Pablo CEU | CEU · Centre of Metabolomics and Bioanalysis (CEMBIO)

Selective targeting of cancer cells is a major challenge for cancer therapy. Many cancer cells overexpress the cystine/glutamate antiporter xCT/CD98 to increase the import of L-cystine for antioxidant defense, thus supporting tumour cell survival and progression 1,2 . We have exploited this feature of cancer cells by transforming xCT/CD98 overexpre...

Introduction A decrease in sperm cell count has been observed along the last several decades, especially in the most developed regions of the world. The use of metabolomics to study the composition of the seminal fluid is a promising approach to gain access to the molecular mechanisms underlying this fact. Objectives In the present work, we aimed...

Human adrenocortical H295R cells have been validated by the OECD Test Guideline 456 to detect chemicals disrupting testosterone and 17β-estradiol (estradiol) biosynthesis. This study evaluated a novel approach to detect disturbances of steroidogenesis in H295R cells, exemplified by prochloraz and five anabolic steroids. Steroid profiles were assess...

Monitoring the central carbon metabolism (CCM) network using liquid chromatography/mass spectrometry (LC-MS) analysis is hampered by the diverse chemical nature of its analytes, which are extremely difficult to analyze using single chromatographic conditions. Furthermore, CCM-related compounds present non-specific adsorption on metal surfaces, caus...

Morphine, a commonly used antinociceptive drug in hospitals, is known to cross the blood-brain barrier (BBB) by first passing through brain endothelial cells. Despite its pain-relieving effect, morphine also has detrimental effects, such as the potential induction of redox imbalance in the brain. However, there is still insufficient evidence of the...

Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (X. citri), is a plant disease affecting Citrus crops worldwide. However, little is known about defense compounds in Citrus. Here, we conducted a mass spectrometry-based metabolomic approach to obtain an overview of the chemical responses of Citrus leaves to X. citri infection. T...

Astrocyte reaction is a complex cellular process involving astrocytes in response to various types of CNS injury and a marker of neurotoxicity. It has been abundantly studied in rodents but relatively poorly in human cells due to limited access to the brain. Astrocytes play important roles in cerebral energy metabolism and are also key players in n...

This chapter covers all the steps of capillary electrophoresis (CE)–mass spectrometry (MS) data treatment with a focus on untargeted metabolomics, from both qualitative and quantitative points of view, to extract the most relevant biological information from the samples. Untargeted CE–MS acquisitions produce massive datasets containing three‐dimens...

Staphylococcus aureus adapts to different environments by sensing and responding to diverse environmental cues. The responses are coordinately regulated by regulatory proteins, and small regulatory RNAs at the transcriptional and translational levels. Here, we characterized teg58, a SarA repressed sRNA, using ChIP-Seq and RNA-Seq analysis of a sarA...

Capillary electrophoresis–mass spectrometry (CE-MS) coupling is a powerful analytical solution bringing together the separation power of CE and the wealth of chemical information afforded by MS. Nevertheless, interfaces making the hyphenation of both techniques possible have always been the subject of a quest for improvement by their users in searc...

The environmental presence of anions of natural origin or anthropogenic origin is gradually increasing. As a tool to tackle this problem, carbazole derivatives are an attractive gateway to the development of luminescent chemosensors. Considering the different mechanisms proposed for anion recognition, the fluorescence properties and anion-binding r...

Untargeted metabolomics is now widely recognized as a useful tool for exploring metabolic changes taking place in biological systems under different conditions. In this article, we aim to provide a short overview of the liquid-phase separation methods hyphenated to MS to perform untargeted metabolomics of biological samples. Each approach is comple...

The use of mass spectrometry methods with triple quadrupole instruments are well established for quantification. However, the preparation of calibration curves is time-consuming and prone to analytical errors. In this study, an innovative internal calibration (IC) approach using a one-standard calibration with a stable isotope-labeled (SIL) standar...

The importance of D-amino acids in mammals associated with enantio-dependent biological functions has been increasingly highlighted. In addition to naturally occurring, D-amino acid supplementation could have a positive biological impact, including cytoprotective implications. In this context, supplementation with D-cysteine has revealed beneficial...

The use of cyclodextrins as drug nano-carrier systems for drug delivery is gaining importance in the pharmaceutical industry due to the interesting pharmacokinetic properties of the resulting inclusion complexes. In the present work, complexes of the anti-cancer alkaloids camptothecin and luotonin A have been prepared with β-cyclodextrin and hydrox...

Capillary electrophoresis coupled to mass spectrometry (CE-MS) is increasingly gaining momentum as an analytical tool in metabolomics, thanks to its ability to obtain information about the most polar elements in biological samples. This has been helped by improvements of robustness in peak identification by means of mobility-scale representations o...

Astrogliosis has been abundantly studied in rodents but relatively poorly in human cells due to limited access to the brain. Astrocytes play important roles in cerebral energy metabolism, and are also key players in neuroinflammation. Astroglial metabolic and inflammatory changes as a function of age have been reported, leading to the hypothesis th...

Innovative methodological approaches are needed to conduct human health and environmental risk assessments on a growing number of marketed chemicals. Metabolomics is progressively proving its value as an efficient strategy to perform toxicological evaluations of new and existing substances, and it will likely become a key strategy to accelerate che...

For several decades now, the analysis of steroids has been a key tool in the diagnosis and monitoring of numerous endocrine pathologies. Thus, the available methods used to analyze steroids in biological samples have dramatically evolved over time following the rapid pace of technology and scientific knowledge. This review aims to synthetize the ad...

The performance of an original CE-MS interface that allows the in-axis positioning of the electrospray with respect to the MS inlet was evaluated. The variations in the geometrical alignment of this configuration in the absence of a nebulizing gas afforded a significant reduction in the sheath-liquid flow rate from 3 µL/min to as low as 300 nL/min....

Under eubiotic conditions commensal microbes are known to provide a competitive barrier against invading bacterial pathogens in the intestinal tract, on the skin or on the vaginal mucosa. Here, we evaluate the role of lung microbiota in Pneumococcus colonization of the lungs. In eubiosis, the lungs of mice were dominantly colonized by Lactobacillus...

Motivation Complex data structures composed of different groups of observations and blocks of variables are increasingly collected in many domains, including metabolomics. Analysing these high-dimensional data constitutes a challenge, and the objective of this article is to present an original multivariate method capable of explicitly taking into a...

Ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) is a powerful and essential technique for metabolite annotation in untargeted metabolomic applications. The aim of this study was to evaluate the performance of diverse tandem MS (MS/MS) acquisition modes, i.e., all ion fragmentation (AIF) and dat...

Capillary zone electrophoresis-mass spectrometry (CE-MS) is a mature analytical tool for the efficient profiling of (highly) polar and ionizable compounds. However, the use of CE-MS in comparison to other separation techniques remains underrepresented in metabolomics, as this analytical approach is still perceived as technically challenging and les...

Tramadol is a synthetic opioid drug used in the treatment of chronic and acute pain. An abnormal prevalence of its misuse in elite sport to overcome pain resulting from prolonged physical effort was recently reported. However, besides its antinociceptive effects, tramadol consumption is associated with negative effects such as numbness, confusion,...

One interesting aspect of antioxidant organic molecules is their use as probes for the detection and quantitation of biologically relevant reactive oxidant species (ROS). In this context, a small library of dihydroterphenyl derivatives has been synthesised and studied as fluorescent chemodosimeters for detecting reactive oxygen species and hypochlo...

Capillary electrophoresis coupled to mass spectrometry (CE-MS) is increasingly gaining momentum as an analytical tool in metabolomics, thanks to its ability to obtain information about the most polar elements in biological samples. This has been helped by improvements in peak robustness by means of mobility-scale representations of the electrophero...

div> Capillary electrophoresis coupled to mass spectrometry (CE-MS) is increasingly gaining momentum as an analytical tool in metabolomics, thanks to its ability to ob- tain information about the most polar elements in biological samples. This has been helped by improvements in peak robustness by means of mobility-scale representations of the elec...

Proliferating cells must coordinate central metabolism with the cell cycle. How central energy metabolism regulates bacterial cell cycle functions is not well understood. Our forward genetic selection unearthed the Krebs cycle enzyme citrate synthase (CitA) as a checkpoint regulator controlling the G1→S transition in the polarized alpha-proteobacte...

In this work, the impact of biological matrices, such as plasma and urine, was evaluated under SFC-HRMS in the field of metabolomics. For this purpose, a representative set of 49 metabolites were selected. The assessment of the matrix effects (ME), the impact of biological fluids on the quality of MS/MS spectra and the robustness of the SFC-HRMS me...

Untargeted metabolomics is now widely recognized as a useful tool for exploring metabolic changes taking place in biological systems under different conditions. By its nature, this is a highly interdisciplinary field of research, and mastering all of the steps comprised in the pipeline can be a challenging task, especially for those researchers new...

Anabolic-androgenic steroids (AAS) are testosterone derivatives developed for steroid-replacement and treatment of debilitating conditions. They are widely used by athletes in elite sports and bodybuilding due to their muscle-building and performance-enhancing properties. Excessive AAS use is associated with cardiovascular diseases, mood changes, e...

Steroids are essential hormones that play a crucial role in homeostasis of many biological processes including sexual development, spermatogenesis, sperm physiology and fertility. Although steroids have been largely studied in many biological matrices (such as urine and plasma), there is very limited information of the steroid content and their stu...

This review describes the analytical methods that have been developed over the years to tackle the high polarity and non-chromophoric nature of amino acids (AAs). First, the historical methods are briefly presented, with a strong focus on the use of derivatization reagents to make AAs detectable with spectroscopic techniques (ultraviolet and fluore...

Coordination of cell cycle progression with central metabolism is fundamental to all cell types and likely underlies differentiation into dispersal cells in bacteria. How central metabolism is monitored to regulate cell cycle functions is poorly understood. A forward genetic selection for cell cycle regulators in the alpha-proteobacterium Caulobact...

Untargeted metabolomics aims to provide a global picture of the metabolites present in the system under study. To this end, making a careful choice of sample preparation is mandatory to obtain reliable and reproducible biological information. In this study, eight different sample preparation techniques were evaluated using Caulobacter crescentus as...

For years, d-amino acids were thought to have a minor function in biological processes compared to that of l-enantiomers. Recently, many studies have shown that d-amino acids are present in high concentrations in microorganisms, plants, mammals and humans and execute specific biological functions. One relevant example is that of d-cysteine, whose h...

Trimethyltin is an organometallic compound, described to be neurotoxic and to trigger neuroinflammation and oxidative stress. Previous studies associated TMT with the perturbation of mitochondrial function, or neurotransmission. However, the mechanisms of toxicity may differ depending on the duration of exposure and on the stage of maturation of br...

Since the ultimate goal of untargeted metabolomics is the analysis of the broadest possible range of metabolites, some new metrics have to be used by researchers to evaluate and select different analytical strategies when multi-platform analyses are considered. In this context, we aimed at developing a scoring approach allowing to compare the perfo...

: Steroidomics studies face the challenge of separating analytical compounds with very similar structures (i.e., isomers). Liquid chromatography (LC) is commonly used to this end, but the shared core structure of this family of compounds compromises effective separations among the numerous chemical analytes with comparable physico-chemical properti...

Toxicology studies can take advantage of omics approaches to better understand the phenomena underlying the phenotypic alterations induced by different types of exposure to certain toxicants. Nevertheless, in order to analyse the data generated from multifactorial omics studies, dedicated data analysis tools are needed. In this work, we propose a n...

The three-component reaction between alkyl- or arylamines, β-ketoesters and chalcones in refluxing ethanol containing a catalytic amount of Ce(IV) ammonium nitrate allowed the construction of a large library of highly substituted dihydro-m-terphenyl derivatives containing β-alkylamino- or β-arylamino ester moieties. This process generates three new...

La métabolomique non ciblée exige des stratégies adéquates pour exploiter au mieux les informations biologiques contenues dans les signaux mesurés. Cette étude propose une approche basée sur la combinaison d’une acquisition LC-HRMS non ciblée, de l’annotation de métabolites en utilisant une base de données de standards et d’un traitement de données...

Capillary electrophoresis (CE) presents many advantageous features as an analytical technique in metabolomics, such as very low consumption of a sample or the possibility to easily detect very polar and ionizable compounds. However, CE remains an approach only used by a few research groups due to a relatively lower sensitivity and, higher analysis...

The aim of this study was to evaluate the suitability of SFC-MS for the analysis of a wide range of compounds including lipophilic and highly hydrophilic substances (log P values comprised between -6 and 11), for its potential application toward human metabolomics. For this purpose, a generic unified chromatography gradient from 2 to 100% organic m...

The use of capillary electrophoresis coupled to mass spectrometry (CE-MS) in metabolomics remains an oddity compared to the widely adopted use of liquid chromatography. It is traditionally regarded as lacking the reproducibility to adequately identify metabolites by their migration times. The major reason is the variability of the velocity of the b...

Although several interfaces for CE-MS hyphenation are commercially available, the development of new versatile, simple and yet efficient and sensitive alternatives remains an important field of research. In a previous work, a simple low sheath-flow interface was developed from inexpensive parts. This interface features a design easy to build, maint...

This work introduces a strategy for decomposing variable contributions within the data obtained from structured metabolomic studies. This approach was applied in the context of an in vitro human neural model to investigate biochemical changes related to neuroinflammation. Neural cells were exposed to the neuroinflammatory toxicant trimethyltin at d...

This chapter focuses on recent examples of the on-line coupling of capillary electrophoresis (CE) and related electrophoresis-based techniques with mass spectrometry (MS) in pharmaceutical and biomedical analyses. The main difference between pharmaceutical and biomedical analysis involves the sample that is analyzed by the analytical system and its...

The current trend for increasing technical complexity in the field of CE-ESI-MS interfaces has incited for more accessible alternatives. In this work, a simple low sheath-flow ESI interface operating in the sub-microliter nanospray regime without nebulizing gas assistance was evaluated. The use of sheath liquid enabled improving the ionization of t...

*Highlights: • Core-shell particles are one of the hottest topics in analytical chemistry • We review the analytical advantages of columns packed with core-shell particles • We review fundamentals and applications of columns packed with core-shell particles • We overview the theory of columns packed with core-shell particles from a practical viewp...

Topoisomerase 1 inhibition is an important strategy in targeted cancer chemotherapy. The drugs currently in use acting on this enzyme belong to the family of the camptothecins, and suffer severe limitations because of their low stability, which is associated with the hydrolysis of the δ-lactone moiety in their E ring. Luotonin A is a natural campto...

A miniaturized fluorescence assay on multi-well plates has been developed to study the solubility enhancement effect of (2-hydroxypropyl)-β-cyclodextrin on three anti-tumor alkaloids. The measurement of the fluorescence emission on a multi-well plate format has been proved to be a rapid and efficient technique to evaluate the solubility of pharmace...

(E)-6-Methyl-4′-amino-2-styrylquinoline (3) is a small molecule with the proper features to potentially diagnose, deliver therapy and monitor response to therapy in protein misfolding diseases. These features include compound fluorescent emission in the NIR region and its ability to interact with both Aβ and prion fibrils, staining them with high s...

Non-steroidal anti-inflammatory drugs are widespread employed in both human and animal health care to reduce ongoing inflammation, pain and fever due to their anti-inflammatory, analgesic and, antipyretic actions. Apart from the well-known biological samples, nowadays these compounds are frequently found in the environment, leading to longterm expo...

Sampling mainstream cigarette smoke is a challenging and stimulating laboratory activity for undergraduate students. In addition to the public health significance, cigarette smoke is an unusual source of analytes to examine the differences between gaseous matrices versus liquid or solid matrices. Sophisticated automated smoking machines complying w...

Luotonin A is an alkaloid structurally related to the natural anti-tumour agent camptothecin. The fluorescence behaviour of luotonin A and a series of six analogues is described in the present work. The influence of solvent polarity and pH on the native fluorescence properties of these alkaloids was studied, finding that in organic solvents or in a...

The interaction between DNA and several newly synthesized derivatives of the natural anticancer compound luotonin A has been studied. The results from our work reveal an effective and selective alkaloid/double-stranded DNA (ds-DNA) interaction. In the presence of increasing amounts of ds-DNA, a noticeable fluorescence quenching of the luotonin A de...

Acetonitrile and methanol are the most popular solvents employed in analytical HPLC, but they suffer from a number of drawbacks from the environmental point of view. Alternative, greener mobile phases employing methanol or the less toxic solvent ethanol as the sole organic solvent are proposed in this paper, and applied to the problem of the separa...

The analysis of beta-carboline alkaloids presents a renewed interest due to their biological relevance and their increasing popularity as recreational drugs. In the present work, a novel chromatographic reverse-phase high-performance liquid chromatography (RP-HPLC) method with fluorimetric detection has been applied to the determination of beta-car...

The quantitation of the natural cytotoxic and anti-inflammatory alkaloid luotonin A and five recently synthesized derivatives is described, constituting the first report of a HPLC method for the analysis of these compounds in human serum samples. The conditions for the chromatographic separation were optimized and the method was validated for the a...