Um protocolo livre de metais foi desenvolvido para sintetizar indanos através da contração de anel de 1,2-di-hidronaftalenos promovida por PhI(OH)OTs (HTIB ou reagente de Koser). Este rearranjo oxidativo pode ser realizado em diversos solventes (MeOH, CH 3 CN, 2,2,2-trifluoroetanol (TFE), 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), e uma mistura 1:4 de TFE:CH 2 Cl 2 ) em condições brandas. A contração de anel fornece indanos trans-1,3-dissubstituídos diastereosseletivamente, os quais são difíceis de obter em química orgânica sintética.A metal-free protocol was developed to synthesize indanes by ring contraction of 1,2-dihydronaphthalenes promoted by PhI(OH)OTs (HTIB or Koser's reagent). This oxidative rearrangement can be performed in several solvents (MeOH, CH 3 CN, 2,2,2-trifluoroethanol (TFE), 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), and a 1:4 mixture of TFE:CH 2 Cl 2 ) under mild conditions. The ring contraction diastereoselectively gives functionalized trans-1,3-disubstituted indanes, which are difficult to obtain in synthetic organic chemistry.Keywords: indanes, hypervalent iodine, ring contraction, 1,2-dihydronaphthalenes, rearrangements IntroductionThe indane ring system is present in several natural products and in non-natural compounds with remarkable biological activity.1 Consequently, efforts have continuously been made to develop new routes to obtain molecules with this unit.2 A typical strategy to synthesize a functionalized indane is by selecting an appropriate indanone, which is then elaborated into the target molecule. 2,3 As tetralones are usually cheaper than indanones, the preparation of indanes starting from a tetralone (or a derivative) through a ring contraction rearrangement could be advantageous. 4 In the last years, hypervalent iodine reagents have become an essential tool in synthetic organic chemistry due to the plethora of reactions that can be performed with them in excellent yield and selectivities. 5 Moreover, hypervalent iodine compounds represent in many cases an alternative to toxic heavy metals. 5 Although the oxidative rearrangement of alkenes mediated by iodine(III) has been described in some papers, 6 the ring contraction of 1,2-dihydronaphthalenes was reported for a few substrates using only p-Me-C 6 H 4 -IF 2 , 6 which led to fluorinated indanes.Herein, we describe an efficient metal-free protocol for the synthesis of indanes under mild conditions. In a preliminary communication, we report the ring contraction of 1,2-dihydronaphthalenes (which are obtained from 1-tetralones) mediated by PhI(OH)OTs (HTIB or Koser's reagent) for a few substrates. 7 In this article, the oxidation of several additional substrates is presented, better defining the reaction scope. Additionally, other reaction conditions were Metal-Free Synthesis of Indanes by Iodine(III)-Mediated Ring Contraction J. Braz. Chem. Soc. 1796 discovered using fluoroalcohols as solvent, which highly improved isolated yields. The best condition employed a 4:1 mixture of CH 2 Cl 2 -TFE that led to indanes in...

Nowadays, there is a growing interest in deeply understanding biological mechanisms not only at the molecular level (biological components) but also the effects of an ongoing biological process in the organism as a whole (biological functionality), as established by the concept of systems biology. Within this context, metabolomics is one of the most powerful bioanalytical strategies that allow obtaining a picture of the metabolites of an organism in the course of a biological process, being considered as a phenotyping tool. Briefly, metabolomics approach consists in identifying and determining the set of metabolites (or specific metabolites) in biological samples (tissues, cells, fluids, or organisms) under normal conditions in comparison with altered states promoted by disease, drug treatment, dietary intervention, or environmental modulation. The aim of this chapter is to review the fundamentals and definitions used in the metabolomics field, as well as to emphasize its importance in systems biology and clinical studies.

METABOLOMICS: DEFINITIONS, STATE-OF-THE-ART AND REPRESENTATIVE APPLICATIONS.Metabolomics is an emerging and promising omics approach used to understand biological mechanisms. By untargeted and targeted metabolomics analyses, metabolites are determined in biological samples (fluids, cells, tissues, etc.) by comparison of control groups with altered groups, undergoing different therapies, submitted to differing stress levels, dietary modulation, or promoted by a disease, or specific condition, etc., using sophisticated analytical techniques, and advanced data treatment and statistical analyses. In this review, the concepts involved in metabolomics studies were presented, describing in details all steps involved in the metabolomics workflow, for untargeted and targeted strategies. Finally, the potential of metabolomics is illustrated by applications in representative areas: clinical, environmental, food and nutrition, forensic toxicology, microbiology, parasitology, plants, and sports. Relevant reviews were compiled to characterize each of these areas, and a corresponding application of untargeted and targeted metabolomics were described.Keywords: metabolomics; untargeted metabolomics; targeted metabolomics; metabolomics workflow. INTRODUÇÃOAs ciências ômicas buscam o entendimento do funcionamento celular dos organismos e suas alterações biológicas. Fazem parte deste conjunto de ciências, a genômica (estudo da alteração dos genes), a transcriptômica (estudo das alterações dos transcritos), a proteômica (estudo das alterações das proteínas), e a metabolômica (estudo das alterações dos metabólitos). Metabólitos são produtos intermediários ou finais do metabolismo em uma amostra biológica.1 O conjunto de todos os metabólitos de baixa massa molecular (até 1500 Da), presentes ou alterados em um sistema biológico, é chamado de metaboloma (do inglês, metabolome).2 A pesquisa relacionada a metabólitos vem sendo desenvolvida há décadas, mas em 1999, Nicholson et al. definiram a metabonômica (do inglês, metabonomics), como sendo a medida quantitativa da resposta metabólica de um sistema biológico após estímulos fisiopatológicos ou modificações genéticas.3 Já o termo metabolômica (do inglês, metabolomics) foi introduzido em 2001, por Oliver Fiehn, como sendo a análise abrangente e quantitativa do metaboloma de um sistema biológico. 4 Além disso, a literatura nos apresenta outras denominações envolvendo esse campo da ciência, tais como: perfil metabólico (do inglês, metabolic profiling), descrito como sendo a análise de metabólitos previamente selecionados de rotas bioquímicas específicas, 5 a impressão digital metabólica (do inglês, metabolic fingerprinting), que é definida como sendo "uma classificação de amostras de acordo com sua origem ou sua relevância biológica", 3 e, por último, análise footprinting (ainda sem tradução para o português), para se referir aos metabólitos excretados por uma célula em condições controladas. Observa-se, portanto, uma divergência em relação às terminologias aplicadas às análises metabolômic...

The present data provide an overall view of the metabolic changes in mitochondrial function produced by (2R,6R)-HNK and related ketamine compounds and offer an insight into the source of the observed variance in antidepressant response elicited by the compounds.

This review article compiles in a critical manner literature publications regarding seven neglected diseases (ND) prioritized in Brazil (Chagas disease, dengue, leishmaniasis, leprosy, malaria, schistosomiasis, and tuberculosis) under the perspective of metabolomics. Both strategies, targeted and untargeted metabolomics, were considered in the compilation. The majority of studies focused on biomarker discovery for diagnostic purposes, and on the search of novel or alternative therapies against the ND under consideration, although temporal progression of the infection at metabolic level was also addressed. Tuberculosis, followed by schistosomiasis, malaria and leishmaniasis are the diseases that received larger attention in terms of number of publications. Dengue and leprosy were the least studied and Chagas disease received intermediate attention. NMR and HPLC-MS technologies continue to predominate among the analytical platforms of choice in the metabolomic studies of ND. A plethora of metabolites were identified in the compiled studies, with expressive predominancy of amino acids, organic acids, carbohydrates, nucleosides, lipids, fatty acids, and derivatives.

Current risk stratification strategies for coronary artery disease (CAD) have low predictive value in asymptomatic subjects classified as intermediate cardiovascular risk. This is relevant because not all coronary events occur in individuals with traditional multiple risk factors. Most importantly, the first manifestation of the disease may be either sudden cardiac death or acute coronary syndrome, after rupture and thrombosis of an unstable non-obstructive atherosclerotic plaque, which was previously silent. The inaccurate stratification using the current models may ultimately subject the individual to excessive or insufficient preventive therapies. A breakthrough in the comprehension of the molecular mechanisms governing the atherosclerosis pathology has driven many researches toward the necessity for a better risk stratification. In this Review, we discuss how metabolomics screening integrated with traditional risk assessments becomes a powerful approach to improve non-invasive CAD subclinical diagnostics. In addition, this Review highlights the findings of metabolomics studies performed by two relevant analytical platforms in current use–mass spectrometry (MS) hyphenated to separation techniques and nuclear magnetic resonance spectroscopy (NMR) –and evaluates critically the challenges for further clinical implementation of metabolomics data. We also discuss the modern understanding of the pathophysiology of atherosclerosis and the limitations of traditional analytical methods. Our aim is to show how discriminant metabolites originated from metabolomics approaches may become promising candidate molecules to aid intermediate risk patient stratification for cardiovascular events and how these tools could successfully meet the demands to translate cardiovascular metabolic biomarkers into clinical settings.

Altered cell metabolism is a hallmark of cancer and critical for its development. Particularly, activation of one-carbon metabolism in tumor cells can sustain oncogenesis while contributing to epigenetic changes and metabolic adaptation during tumor progression. We assessed whether increased one-carbon metabolism activity is a metabolic feature of invasive ductal carcinoma (IDC). Differences in the metabolic profile between biopsies from IDC (n = 47) and its adjacent tissue (n = 43) and between biopsies from different breast cancer subtypes were assessed by gas spectrometry in targeted (Biocrates Life Science ®) and untargeted approaches, respectively. The metabolomics data were statistically treated using MetaboAnalyst 4.0, SIMCA P+ (version 12.01), Statistica 10 software and t test with p < 0.05. The Cancer Genome Atlas breast cancer dataset was also assessed to validate the metabolomic profile of IDC. Our targeted metabolomics analysis showed distinct metabolomics profiles between IDC and adjacent tissue, where IDC displayed a comparative enrichment of metabolites involved in one-carbon metabolism (serine, glycine, threonine, and methionine) and a predicted increase in the activity of pathways that receive and donate carbon units (i.e., folate, methionine, and homocysteine). In addition, the targeted and untargeted metabolomics analyses showed similar metabolomics profiles between breast cancer subtypes. The gene set enrichment analysis identified different transcription-related functions between IDC and non-tumor tissues that involved onecarbon metabolism. Our data suggest that one-carbon metabolism may be a central pathway in IDC and even in general breast tumors, representing a potential target for its treatment and prevention.

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