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.