Hydrogen magnetic resonance spectroscopy (H MRS) performed at low fields is a non-invasive method... more Hydrogen magnetic resonance spectroscopy (H MRS) performed at low fields is a non-invasive method and a useful tool for the diagnosis of tumors in vivo. High field H MRS, on the other hand, has been used to study biochemical changes in distinct pathologies in vitro based on the pattern of metabolite distribution in tissue extracts. It is also useful for identifying the distinct metabolic profiles of specific histological subtypes of brain tumors, aiming for the optimization of the in vivo H NMR spectroscopy protocols. The accurate analysis and classification of different spectra, however, remains a challenge. In this work, brain tissue samples from patients with various types of brain tumors were analyzed by high field (B0 = 11.7 ) H MRS in the region 1.22 – 4.25 ppm. Spectra were corrected to phase shift, baseline corrected using a linear fit and point wise scaled by the sum of all intensities (normalized to unit area). Partial Least Square Discriminant Analysis (PLS-DA) on autosca...
Este trabalho consistiu em aplicacoes independentes da RMN dentro nas areas da quimica de produto... more Este trabalho consistiu em aplicacoes independentes da RMN dentro nas areas da quimica de produtos naturais e da bioquimica. Inicialmente, a implantacao e consolidacao de estudos de rotas biossinteticas em nosso instituto foram alcancadas mediante experimentos de marcacao com C da terreina e do terreinol, ambos produtos naturais isolados do fungo Aspergillus terreus. No caso do metabolito inedito terreinol, o padrao de incorporacao de [1-C ]-D-glicose determinado atraves de RMN de C revelou uma origem mista, predominantemente policetidica com o envolvimento de seis unidades de acetil-/malonil adicionadas via coenzima A. A marcacao da metila aromatica do terreinol, adjacente a outra posicao enriquecida, indica alquilacao de um intermediario policetidico pela metionina. Ainda neste trabalho, extratos de tumores de cerebro foram investigados por RMN de H de alta resolucao para determinar a composicao quimica dos tecidos buscando identificar possiveis alteracoes metabolicas associadas a caracteristicas bioquimicas de tecidos tumorais e determinar marcadores quimicos capazes de classificar os tumores quanto ao tipo e grau de agressividade. A aplicacao de analise discriminatoria de minimos quadrados parciais em nossos dados mostrou, uma correlacao inedita entre a razao glicina/inositol e o grau de agressividade em tumores neurogliais. Alem disso, foi possivel relacionar metastases a concentracoes de inositol muito baixas comparadas aos tumores primarios do SNC. Estas alteracoes metabolicas foram interpretadas em termos da indiferenciacao celular, dos mecanismos de resistencia e perpetuacao dos tumores em meios adversos e da sua capacidade anti-apoptotica. Abstract
O objetivo deste trabalho e o estudo espectroscopico de derivados 8,9-seco-lanostanos e 8,9-seco-... more O objetivo deste trabalho e o estudo espectroscopico de derivados 8,9-seco-lanostanos e 8,9-seco- 7,9-ciclo-lanostanos utilizando-se espectros de RMNH e C em 1 e 2 Dimensoes, que atualmente, sao utilizados de forma rotineira. A partir do lanosterol 1obtivemos 4 derivados do tipo 8,9-seco-lanostanos, sendo que um deles e inedito e, 2 derivados do tipo 8,9-seco-7,9-ciclo-lanostanos, sendo que um deles e inedito. O estudo es - pectroscopico destes 6 derivados foi bastante minucioso. Dentre os derivados estudados, a 3b-acetoxi-9-hidroxi-5a-8,9-seco- lanostan-8-ona (monoalcool 6) e o 3b-acetoxi-8,9-diidroxi-5a-8,9-seco-lanostano (diol 8), sofrem processos de permuta intramoleculares lentos para a escala de tempo da Ressonância Magnetica Nuclear, fazendo com que alguns carbonos e protons destes dois derivados, tenham vizinhancas quimicas e magneticas diferentes. Para o monoalcool 6 foram feitos calculos de mecânica molecular do tipo MM2, que nos mostraram a existencia de dois conformeros preferenciais (de menor energia) com barreiras de energia iguais a 48,72 e a 55,41 KJ/mol. A razao entre as populacoes dos conformeros de 6 e de aproximadamente 1:21 e isso faz com que, nos espectros de RMNC a temperaturas baixas, observemos somente os sinais referentes ao conformero que tem maior populacao. Ja no caso do diol 8, os calculos de mecânica molecular do tipo MM2, mostraram a existencia de 4 conformeros de menor energia. Entretanto, observando-se os valores de suas populacoes, notamos que no caso de 2 destes conformeros, estes valores sao despreziveis. Assim, a relacao entre as populacoes dos 2 conformeros preferenciais do diol 8 e de aproximadamente 1:2 e os valores de barreiras de energia entre eles sao iguais a 47,28 e a 48,59 KJ/mol. Os sinais observados no espectro de RMNC a 90°C do diol 8 se referem a media dos sinais dos 2 conformeros. No caso do estudo espectroscopico dos outros 2 derivados ciclo-decânicos (3b- ace - toxi-5a-8,9-seco-lanostano-8,9-dicetona-dicetona 4 e 3b-acetoxi-5a-8,9-seco-(9E)-lanost-ten-8-ona - cetona olefinica 9) e dos derivados lanos - tânicos contendo aneis fundidos de 5 e 7 membros (3 b-acetoxi-8,9-diidro-8,9-seco-7,9-ciclo-5a,7a-Ianostano - alcool 7 e 3 b-acetoxi-5a-8,9-seco-7,9-ciclo-7-lanosten-8-ona - cetona ab insaturada 10) nao foram observados processos de permuta intramoleculares. Vale salientar que a existencia de interconversoes intramoleculares para derivados do tipo ciclo-decânicos como os estudados por nos e bastante incomum. Abstract
Low-calorie structured lipids (SLs) rich in behenic and oleic acids were produced by enzymatic (E... more Low-calorie structured lipids (SLs) rich in behenic and oleic acids were produced by enzymatic (EI) and chemical interesterification (CI) of high oleic sunflower oil and fully hydrogenated Crambe abyssinica oil in proportions of 60:40, 50:50, 40:60 and 30:70 (w/w), respectively. The immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) was used for 3 h at 70 °C at a dosage of 7% (w/w) free of organic solvents. The original blend (BE) and the reaction products were evaluated for their fatty acid (FA) and triacylglycerols (TAG) compositions, solid fat contents, thermal analysis, regiospecific distribution of the FA, microstructure and polymorphism. The tendency was towards a reduction in the C52, C54, C60, C62 and C64 TAG contents and an increase in the C56, C58 e C66 TAG contents, therefore the solid fat content was reduced. There was lower acyl migration at the sn-2 position of the TAGs in EI as compared to CI in all the blends ratios. Needle-like crystals were predominan...
Omics : a journal of integrative biology, Jul 1, 2016
Roux-en-Y gastric bypass (RYGB) surgery goes beyond weight loss to induce early beneficial hormon... more Roux-en-Y gastric bypass (RYGB) surgery goes beyond weight loss to induce early beneficial hormonal changes that favor glycemic control. In this prospective study, ten obese subjects diagnosed with type 2 diabetes underwent bariatric surgery. Mixed-meal tolerance test was performed before and 12 months after RYGB, and the outcomes were investigated by a time-resolved hydrogen nuclear magnetic resonance ((1)H NMR)-based metabolomics. To the best of our knowledge, no previous omics-driven study has used time-resolved (1)H NMR-based metabolomics to investigate bariatric surgery outcomes. Our results presented here show a significant decrease in glucose levels after bariatric surgery (from 159.80 ± 61.43 to 100.00 ± 22.94 mg/dL), demonstrating type 2 diabetes remission (p < 0.05). The metabolic profile indicated lower levels of lactate, alanine, and branched chain amino acids for the operated subject at fasting state after the surgery. However, soon after food ingestion, the levels o...
Parameters and symbols for use in Nuclear Magnetic Resonance (IUPAC recomendations 1997): NMR is ... more Parameters and symbols for use in Nuclear Magnetic Resonance (IUPAC recomendations 1997): NMR is now frequently the technique of choice for determination of chemical structure in solution. Its uses also span structure in solids and mobility at the molecular level in all phases. The research literature in the subject is vast and ever-increasing. Unfortunately, many articles do not contain sufficient information for experiments to be repeated elsewhere, and there are many variations in the usage of symbols for the same physical quantity. It is the aim of the present recommendations to provide simple check-lists that will enable such problems to be minimised in a way that is consistent with general IUPAC formulation. The area of medical NMR and imaging is not specifically addressed in these recommendations, which are principally aimed at mainstream use of NMR by chemists (of all sub-disciplines) and by many physicists, biologists, material scientists and geologists etc. working with NMR.
An overview of the recent discoveries concerning the ecology and chemistry of pollination in Braz... more An overview of the recent discoveries concerning the ecology and chemistry of pollination in Brazilian orchids is presented, preceded by a brief summary of orchid systematics, morphology and breeding systems. Floral features promoting cross-pollination are described in detail. Recent discoveries in Brazilian orchids pollinated by Euglossini and oil-gathering bees are discussed and illustrated. Pollination in Brazilian Maxillariinae orchids is described in detail. Fragrance main components in some rewardless species are provided and illustrated. In addition, floral secretions in some reward-offering species are discussed and illustrated in detail. Study cases concerning sexual mimicry, or " pseudo-copulation " , in which morphological and chemical flower features elicit the attraction of sexually-excited insects that promote pollination during copulation attempts with the flowers, are emphasized. We expect that the study of the chemistry and ecology of pollination in Orchid...
Quorum Sensing vs Quorum Quenching: A Battle with No End in Sight, 2014
Bacteria communicate with each other by producing and detecting small diffusible molecules in a p... more Bacteria communicate with each other by producing and detecting small diffusible molecules in a process called quorum sensing (QS). This mechanism allows bacteria to coordinate their activities in response to their populations. For instance, QS regulates diverse phenotypes, such as virulence factors bioluminescence, biofilm formation, and antibiotic production, in various bacteria that survived in plants and mammals, only after reaching critical populations (Waters and Bassler 2005).
Hydrogen magnetic resonance spectroscopy (H MRS) performed at low fields is a non-invasive method... more Hydrogen magnetic resonance spectroscopy (H MRS) performed at low fields is a non-invasive method and a useful tool for the diagnosis of tumors in vivo. High field H MRS, on the other hand, has been used to study biochemical changes in distinct pathologies in vitro based on the pattern of metabolite distribution in tissue extracts. It is also useful for identifying the distinct metabolic profiles of specific histological subtypes of brain tumors, aiming for the optimization of the in vivo H NMR spectroscopy protocols. The accurate analysis and classification of different spectra, however, remains a challenge. In this work, brain tissue samples from patients with various types of brain tumors were analyzed by high field (B0 = 11.7 ) H MRS in the region 1.22 – 4.25 ppm. Spectra were corrected to phase shift, baseline corrected using a linear fit and point wise scaled by the sum of all intensities (normalized to unit area). Partial Least Square Discriminant Analysis (PLS-DA) on autosca...
Este trabalho consistiu em aplicacoes independentes da RMN dentro nas areas da quimica de produto... more Este trabalho consistiu em aplicacoes independentes da RMN dentro nas areas da quimica de produtos naturais e da bioquimica. Inicialmente, a implantacao e consolidacao de estudos de rotas biossinteticas em nosso instituto foram alcancadas mediante experimentos de marcacao com C da terreina e do terreinol, ambos produtos naturais isolados do fungo Aspergillus terreus. No caso do metabolito inedito terreinol, o padrao de incorporacao de [1-C ]-D-glicose determinado atraves de RMN de C revelou uma origem mista, predominantemente policetidica com o envolvimento de seis unidades de acetil-/malonil adicionadas via coenzima A. A marcacao da metila aromatica do terreinol, adjacente a outra posicao enriquecida, indica alquilacao de um intermediario policetidico pela metionina. Ainda neste trabalho, extratos de tumores de cerebro foram investigados por RMN de H de alta resolucao para determinar a composicao quimica dos tecidos buscando identificar possiveis alteracoes metabolicas associadas a caracteristicas bioquimicas de tecidos tumorais e determinar marcadores quimicos capazes de classificar os tumores quanto ao tipo e grau de agressividade. A aplicacao de analise discriminatoria de minimos quadrados parciais em nossos dados mostrou, uma correlacao inedita entre a razao glicina/inositol e o grau de agressividade em tumores neurogliais. Alem disso, foi possivel relacionar metastases a concentracoes de inositol muito baixas comparadas aos tumores primarios do SNC. Estas alteracoes metabolicas foram interpretadas em termos da indiferenciacao celular, dos mecanismos de resistencia e perpetuacao dos tumores em meios adversos e da sua capacidade anti-apoptotica. Abstract
O objetivo deste trabalho e o estudo espectroscopico de derivados 8,9-seco-lanostanos e 8,9-seco-... more O objetivo deste trabalho e o estudo espectroscopico de derivados 8,9-seco-lanostanos e 8,9-seco- 7,9-ciclo-lanostanos utilizando-se espectros de RMNH e C em 1 e 2 Dimensoes, que atualmente, sao utilizados de forma rotineira. A partir do lanosterol 1obtivemos 4 derivados do tipo 8,9-seco-lanostanos, sendo que um deles e inedito e, 2 derivados do tipo 8,9-seco-7,9-ciclo-lanostanos, sendo que um deles e inedito. O estudo es - pectroscopico destes 6 derivados foi bastante minucioso. Dentre os derivados estudados, a 3b-acetoxi-9-hidroxi-5a-8,9-seco- lanostan-8-ona (monoalcool 6) e o 3b-acetoxi-8,9-diidroxi-5a-8,9-seco-lanostano (diol 8), sofrem processos de permuta intramoleculares lentos para a escala de tempo da Ressonância Magnetica Nuclear, fazendo com que alguns carbonos e protons destes dois derivados, tenham vizinhancas quimicas e magneticas diferentes. Para o monoalcool 6 foram feitos calculos de mecânica molecular do tipo MM2, que nos mostraram a existencia de dois conformeros preferenciais (de menor energia) com barreiras de energia iguais a 48,72 e a 55,41 KJ/mol. A razao entre as populacoes dos conformeros de 6 e de aproximadamente 1:21 e isso faz com que, nos espectros de RMNC a temperaturas baixas, observemos somente os sinais referentes ao conformero que tem maior populacao. Ja no caso do diol 8, os calculos de mecânica molecular do tipo MM2, mostraram a existencia de 4 conformeros de menor energia. Entretanto, observando-se os valores de suas populacoes, notamos que no caso de 2 destes conformeros, estes valores sao despreziveis. Assim, a relacao entre as populacoes dos 2 conformeros preferenciais do diol 8 e de aproximadamente 1:2 e os valores de barreiras de energia entre eles sao iguais a 47,28 e a 48,59 KJ/mol. Os sinais observados no espectro de RMNC a 90°C do diol 8 se referem a media dos sinais dos 2 conformeros. No caso do estudo espectroscopico dos outros 2 derivados ciclo-decânicos (3b- ace - toxi-5a-8,9-seco-lanostano-8,9-dicetona-dicetona 4 e 3b-acetoxi-5a-8,9-seco-(9E)-lanost-ten-8-ona - cetona olefinica 9) e dos derivados lanos - tânicos contendo aneis fundidos de 5 e 7 membros (3 b-acetoxi-8,9-diidro-8,9-seco-7,9-ciclo-5a,7a-Ianostano - alcool 7 e 3 b-acetoxi-5a-8,9-seco-7,9-ciclo-7-lanosten-8-ona - cetona ab insaturada 10) nao foram observados processos de permuta intramoleculares. Vale salientar que a existencia de interconversoes intramoleculares para derivados do tipo ciclo-decânicos como os estudados por nos e bastante incomum. Abstract
Low-calorie structured lipids (SLs) rich in behenic and oleic acids were produced by enzymatic (E... more Low-calorie structured lipids (SLs) rich in behenic and oleic acids were produced by enzymatic (EI) and chemical interesterification (CI) of high oleic sunflower oil and fully hydrogenated Crambe abyssinica oil in proportions of 60:40, 50:50, 40:60 and 30:70 (w/w), respectively. The immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) was used for 3 h at 70 °C at a dosage of 7% (w/w) free of organic solvents. The original blend (BE) and the reaction products were evaluated for their fatty acid (FA) and triacylglycerols (TAG) compositions, solid fat contents, thermal analysis, regiospecific distribution of the FA, microstructure and polymorphism. The tendency was towards a reduction in the C52, C54, C60, C62 and C64 TAG contents and an increase in the C56, C58 e C66 TAG contents, therefore the solid fat content was reduced. There was lower acyl migration at the sn-2 position of the TAGs in EI as compared to CI in all the blends ratios. Needle-like crystals were predominan...
Omics : a journal of integrative biology, Jul 1, 2016
Roux-en-Y gastric bypass (RYGB) surgery goes beyond weight loss to induce early beneficial hormon... more Roux-en-Y gastric bypass (RYGB) surgery goes beyond weight loss to induce early beneficial hormonal changes that favor glycemic control. In this prospective study, ten obese subjects diagnosed with type 2 diabetes underwent bariatric surgery. Mixed-meal tolerance test was performed before and 12 months after RYGB, and the outcomes were investigated by a time-resolved hydrogen nuclear magnetic resonance ((1)H NMR)-based metabolomics. To the best of our knowledge, no previous omics-driven study has used time-resolved (1)H NMR-based metabolomics to investigate bariatric surgery outcomes. Our results presented here show a significant decrease in glucose levels after bariatric surgery (from 159.80 ± 61.43 to 100.00 ± 22.94 mg/dL), demonstrating type 2 diabetes remission (p < 0.05). The metabolic profile indicated lower levels of lactate, alanine, and branched chain amino acids for the operated subject at fasting state after the surgery. However, soon after food ingestion, the levels o...
Parameters and symbols for use in Nuclear Magnetic Resonance (IUPAC recomendations 1997): NMR is ... more Parameters and symbols for use in Nuclear Magnetic Resonance (IUPAC recomendations 1997): NMR is now frequently the technique of choice for determination of chemical structure in solution. Its uses also span structure in solids and mobility at the molecular level in all phases. The research literature in the subject is vast and ever-increasing. Unfortunately, many articles do not contain sufficient information for experiments to be repeated elsewhere, and there are many variations in the usage of symbols for the same physical quantity. It is the aim of the present recommendations to provide simple check-lists that will enable such problems to be minimised in a way that is consistent with general IUPAC formulation. The area of medical NMR and imaging is not specifically addressed in these recommendations, which are principally aimed at mainstream use of NMR by chemists (of all sub-disciplines) and by many physicists, biologists, material scientists and geologists etc. working with NMR.
An overview of the recent discoveries concerning the ecology and chemistry of pollination in Braz... more An overview of the recent discoveries concerning the ecology and chemistry of pollination in Brazilian orchids is presented, preceded by a brief summary of orchid systematics, morphology and breeding systems. Floral features promoting cross-pollination are described in detail. Recent discoveries in Brazilian orchids pollinated by Euglossini and oil-gathering bees are discussed and illustrated. Pollination in Brazilian Maxillariinae orchids is described in detail. Fragrance main components in some rewardless species are provided and illustrated. In addition, floral secretions in some reward-offering species are discussed and illustrated in detail. Study cases concerning sexual mimicry, or " pseudo-copulation " , in which morphological and chemical flower features elicit the attraction of sexually-excited insects that promote pollination during copulation attempts with the flowers, are emphasized. We expect that the study of the chemistry and ecology of pollination in Orchid...
Quorum Sensing vs Quorum Quenching: A Battle with No End in Sight, 2014
Bacteria communicate with each other by producing and detecting small diffusible molecules in a p... more Bacteria communicate with each other by producing and detecting small diffusible molecules in a process called quorum sensing (QS). This mechanism allows bacteria to coordinate their activities in response to their populations. For instance, QS regulates diverse phenotypes, such as virulence factors bioluminescence, biofilm formation, and antibiotic production, in various bacteria that survived in plants and mammals, only after reaching critical populations (Waters and Bassler 2005).
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Papers by Anita Jocelyne Marsaioli