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Simo C.,Laboratory of Foodomics | Cifuentes A.,Laboratory of Foodomics | Kasicka V.,Czech Institute of Organic Chemistry And Biochemistry
Methods in Molecular Biology

In this chapter, the potential of capillary electrophoresis-mass spectrometry (CE-MS) for peptide analysis is demonstrated by the presentation of two different strategies typically followed in analysis of these biomolecules by CE-MS. The first one is a target-based approach and it is used to detect a toxic oligopeptide in a complex matrix. Namely, CE-MS using an ion trap MS analyzer is applied to detect and quantify γ-glutamyl-S-ethenyl-cysteine (GEC) bioactive dipeptide in a legume plant. The second one is a shotgunlike methodology used for proteomic analysis. Particularly, CE-MS using a time-of- flight MS analyzer is employed to investigate the substantial equivalence between a genetically modified (GM) variety of soybean and its conventional isogenic counterpart. These generic methods have broad applications for the analysis of peptides in a large variety of matrices, including applications in the area of proteomics and peptidomics. © Springer Science+Business Media, LLC 2013. Source

Valdes A.,Laboratory of Foodomics | Garcia-Canas V.,Laboratory of Foodomics | Cifuentes A.,Laboratory of Foodomics

Nowadays, new solutions focused on the replacement of reagents hazardous to human health are highly demanded in laboratories and Green Chemistry. In the present work, GelGreen, a new nonhazardous DNA staining reagent, has been assayed for the first time to analyze double-stranded DNA by CGE with LIF detection. The effect of GelGreen concentration on S/N ratio and migration time of a wide concentration range of standard DNA mixtures was evaluated. Under optimum GelGreen concentration in the sieving buffer efficient and sensitive separations of DNA fragments with sizes from 100-500 base pairs (bp) were obtained. A comparison in terms of resolution, time of analysis, LOD, LOQ, reproducibility, sizing performance, and cost of analysis was established between two optimized CGE-LIF protocols for DNA analysis, one based on the dye YOPRO-1 (typically used for CGE-LIF of DNA fragments) and another one using the new GelGreen. Analyses using YOPRO-1 were faster than those using GelGreen (ca. 31 min versus 34 min for the analysis of 100-500 bp DNA fragments). On the other side, sensitivity using GelGreen was twofold higher than that using YOPRO-1. The cost of analysis was significantly cheaper (ninefold) using GelGreen than with YOPRO-1. The resolution values and sizing performance were not significantly different between the two dyes (e.g. both dyes allowed the separation of fragments differing in only 2 bp in the 100-200 bp range). The usefulness of the separation method using GelGreen is demonstrated by the characterization of different amplicons obtained by PCR. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ibanez C.,Laboratory of Foodomics | Simo C.,Laboratory of Foodomics | Cifuentes A.,Laboratory of Foodomics

Alzheimer's disease (AD) is a neurodegenerative multifactorial disease whose cause is still unknown. The majority of AD biochemical markers currently available have been developed as an extension of targeted physiological studies on the basis of the "amyloid hypothesis." The potential of metabolomics for the discovery of novel biomarkers and elucidation of new biochemical pathways modified in the progression of AD is highlighted in this review work. A variety of nontargeted metabolomic approaches for the discrimination between healthy subjects and AD patients are described. Moreover, the feasibility of metabolomics to predict progression to AD in individuals with mild cognitive impairment is also presented. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ibanez C.,Laboratory of Foodomics | Simo C.,Laboratory of Foodomics | Garcia-Canas V.,Laboratory of Foodomics | Gomez-Martinez A.,University Miguel Hernandez | And 2 more authors.

In this study, an analytical multiplatform is presented to carry out a broad metabolomic study on the anti-proliferative effect of dietary polyphenols on human colon cancer cells. CE, RP/UPLC, and HILIC/UPLC all coupled to TOF MS were combined to achieve a global metabolomic examination of the effect of dietary polyphenols on HT29 colon cancer cells. By the use of a nontargeted metabolomic approach, metabolites showing significant different expression after the polyphenols treatment were identified in colon cancer cells. It was demonstrated that this multianalytical platform provided extensive metabolic information and coverage due to its complementary nature. Differences observed in metabolic profiles from CE-TOF MS, RP/UPLC-TOF MS, and HILIC/UPLC-TOF MS can be mainly assigned to their different separation mechanisms without discarding the influence of the different tools used for data processing. Changes in glutathione metabolism with an enhanced reduced glutathione/oxidized glutathione (GSH/GSSG) ratio were detected in polyphenols-treated cells. Moreover, significant alterations in polyamines content with important implications in cancer proliferation were observed after the treatment with polyphenols. These results from metabolomics can explain the chemopreventive effect of the tested dietary polyphenols on colon cancer and may be of importance for future prevention and/or treatment of this disease. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ibanez C.,Laboratory of Foodomics | Simo C.,Laboratory of Foodomics | Martin-Alvarez P.J.,Laboratory of Foodomics | Kivipelto M.,Karolinska Institutet | And 3 more authors.
Analytical Chemistry

Alzheimer's disease (AD) is the most prevalent form of dementia with an estimated worldwide prevalence of over 30 million people, and its incidence is expected to increase dramatically with an increasing elderly population. Up until now, cerebrospinal fluid (CSF) has been the preferred sample to investigate central nervous system (CNS) disorders since its composition is directly related to metabolite production in the brain. In this work, a nontargeted metabolomic approach based on capillary electrophoresis-mass spectrometry (CE-MS) is developed to examine metabolic differences in CSF samples from subjects with different cognitive status related to AD progression. To do this, CSF samples from 85 subjects were obtained from patients with (i) subjective cognitive impairment (SCI, i.e. control group), (ii) mild cognitive impairment (MCI) which remained stable after a follow-up period of 2 years, (iii) MCI which progressed to AD within a 2-year time after the initial MCI diagnostic and, (iv) diagnosed AD. A prediction model for AD progression using multivariate statistical analysis based on CE-MS metabolomics of CSF samples was obtained using 73 CSF samples. Using our model, we were able to correctly classify 97-100% of the samples in the diagnostic groups. The prediction power was confirmed in a blind small test set of 12 CSF samples, reaching a 83% of diagnostic accuracy. The obtained predictive values were higher than those reported with classical CSF AD biomarkers (Aβ42 and tau) but need to be confirmed in larger samples cohorts. Choline, dimethylarginine, arginine, valine, proline, serine, histidine, creatine, carnitine, and suberylglycine were identified as possible disease progression biomarkers. Our results suggest that CE-MS metabolomics of CSF samples can be a useful tool to predict AD progression. © 2012 American Chemical Society. Source

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