Cariniana estrellensis (Raddi) Kuntze seedlings have been used in forest restoration programs in the Atlantic Forest biome. However, despite the economic and ecological relevance of this species, to date no general method for rapid identification of primary and secondary metabolites of C. estrellensis leaves has been reported. In this work, we explore the feasibility of using rapid analysis by nuclear magnetic resonance techniques and liquid chromatography coupled to diode array, charged aerosol, and mass detection. The main secondary metabolites identified were hydrolysable tannins, quinic acid, hydroxycinnamic acids (trans-p-coumaric acid, cis p coumaric acid, and trans-ferulic acid), and flavonoids (kaempferol and quercetin derivatives). These compounds are particularly useful as chemotaxonomic markers for the genus Cariniana and for the family Lecythidaceae, and may also be important for pharmacological uses and for the survival of the seedlings in reforestation programs.

Abstract The oil from the fruit of peach palm or Pupunha (Bactris gasipaes) is an example of a material with low-cost and good antioxidant capacity. However, Conventional methods for measuring oil content are time-consuming, labor-intensive and use toxic chemicals. In this sense, the aim of this study was evaluated fast and non-destructive spectroscopy methods, such as Near Infrared (NIR) and Time-Domain Nuclear Magnetic Resonance (TD-NMR) (CPMG and ROSE pulse sequences), to quantify the oil content in pupunha flours collected in the amazon forest. For this, 93 samples were used and the results showed three distinct levels of oil in the samples: high, medium and low oil content. Furthermore, the determination coefficient (R2) reached values of 0.92, 0.92 and 0.70 for NIR, TD-NMR (ROSE) and TD-NMR (CPMG), respectively. Therefore, the NIR and TD-NMR (ROSE) methods demonstrate a higher prediction efficiency, with the NIR achieving 100% classification of the samples.

Abstract Kafirins, water-insoluble proteins from Sweet Sorghum BR501 grains, have been an alternative to prepare edible coatings for food due to their hydrophobic character. In this work, the secondary structures (SS) content of reduced (SSr) and unreduced (SSu) kafirins were determined by 13C solid-state-NMR spectroscopy using areas of carbonyl peak. The SS elucidate by fitting the signal with the Lorentzian function shows 56% and 59% of α-helix and 40% and 12% of β-sheet structures for SSr and SSu, respectively. The SS also were elucidated by a Singular value decomposition- SVD method shows 55% and 49% of α-helix and 12% and 8% of β-sheet structure for SSr and SSu, respectively. Since SVD does not depend on the operator and has higher correlation coefficients for α-helix (0.96%) and β-sheet (0.91%), it is a reliable method to quantify the SS of insoluble proteins using the 13C NMR signal.

Growth in the international popularity of Brazil nuts oil (Bertholletia excelsa, Bonpl.) has demanded a closer look at quality aspects of the nuts. In this context, time-domain 1H nuclear magnetic resonance spectroscopy (TD-NMR) can be a useful tool for assessing the lipid portion of such matrices. In this work, a TD-NMR method was developed and validated to assess the oil content directly from Brazil nuts following the ISO 10565:1998 and DOQ-CGCRE-008. Full validation was addressed covering the working range from 0.67 to 25.00 g (coefficient of determination, R2= 0.9993). Limits of detection (LOD) and quantification (LOQ) were 0.20 and 0.67 g, respectively. The repeatability and intermediate precision assays met the guide requirements. Oil contents obtained in two laboratories (different equipment) were statistically similar (66.93 ± 4.69 and 70.13 ± 4.15%), highlighting the method’s robustness. The developed approach has the potential to be adopted as an industrial reference method for in situ monitoring of Brazil nuts oil contents.

Abstract ‘BRS 421’ and ‘BRS 423’ are high-oleic runner type peanut cultivars, adapted to the main peanut-producing areas in Brazil and partially resistant to spotted wilt. ‘BRS 421’ has a medium cycle and large seed size, while BRS ‘423’ has a short cycle and regular runner seed size.

Abstract BRS 425 is a high-oleic runner peanut cultivar related to wild ancestral parents, partially resistant to early and late leaf spot and spotted wilt. It is large-seeded and contains 46% oil. BRS 425 is adapted to the main peanut-producing regions of Brazil.

A fast procedure using time-domain nuclear magnetic resonance (TD-NMR) to detect olive oil adulteration with polyunsaturated vegetable oils in filled bottles is proposed. The 1H transverse relaxation times (T2) of 37 commercial samples were measured using low-field nuclear magnetic resonance (LF-NMR) spectrometer and a unilateral nuclear magnetic resonance (UNMR) sensor. Results obtained with LF-NMR revealed better feasibility when compared with the UNMR sensor, with higher signal-to-noise (S/N) ratio and larger difference in the T2 decays. Principal component analysis (PCA) exhibited tight and well-separated clusters of pure olive oil (OO), pure soybean oil (SO), and blends of OO/SO (adulterated samples). Soft independent modeling of class analogies analysis (SIMCA) classification model indicated that five brands of olive oil commercialized in Brazil were adulterated with polyunsaturated fatty acids, further confirmed by high-resolution NMR. Overall, LF-NMR provided a fast procedure for screening olive oil authenticity directly in the sealed bottles.

The aim of this paper was to present a simple and fast way of simulating Nuclear Magnetic Resonance signals using the Bloch equations. These phenomenological equations describe the classical behavior of macroscopic magnetization and are easily simulated using rotation matrices. Many NMR pulse sequences can be simulated with this formalism, allowing a quantitative description of the influence of many experimental parameters. Finally, the paper presents simulations of conventional sequences such as Single Pulse, Inversion Recovery, Spin Echo and CPMG.

The need for effective and reliable quality control in products from pharmaceutical industries renders the analyses of their active ingredients and constituents of great importance. This study presents the theoretical basis of ¹H NMR for quantitative analyses and an example of the method validation according to Resolution RE Nº 899 by the Brazilian National Health Surveillance Agency (ANVISA), in which the compound paracetamol was the active ingredient. All evaluated parameters (selectivity, linearity, accuracy, repeatability and robustness) showed satisfactory results. It was concluded that a single NMR measurement provides structural and quantitative information of active components and excipients in the sample.

Atomic Force Microscopy (AFM) can be used to obtain high-resolution topographical images of bacteria revealing surface details and cell integrity. During scanning however, the interactions between the AFM probe and the membrane results in distortion of the images. Such distortions or artifacts are the result of geometrical effects related to bacterial cell height, specimen curvature and the AFM probe geometry. The most common artifact in imaging is surface broadening, what can lead to errors in bacterial sizing. Several methods of correction have been proposed to compensate for these artifacts and in this study we describe a simple geometric model for the interaction between the tip (a pyramidal shaped AFM probe) and the bacterium (Escherichia coli JM-109 strain) to minimize the enlarging effect. Approaches to bacteria immobilization and examples of AFM images analysis are also described.

Nuclear magnetic resonance (NMR) is one of the most versatile analytical techniques for chemical, biochemical and medical applications. Despite this great success, NMR is seldom used as a tool in industrial applications. The first application of NMR in flowing samples was published in 1951. However, only in the last ten years Flow NMR has gained momentum and new and potential applications have been proposed. In this review we present the historical evolution of flow or online NMR spectroscopy and imaging, and current developments for use in the automation of industrial processes.

Analizou-se o papel do exopolissacarídeo (EPS) no mecanismo de resistência ao Cu2+ da Xanthomonas axonopodis pv. citri (Xac) com as espectroscopias de infravermelho com transformada de Fourier (FTIR), ressonância paramagnética eletrônica (RPE) e ressonância magnética nuclear (RMN). Os dados de FTIR demonstraram que as células cultivadas na presença de 0.2 mmol L-1 de CuSO4 produziram uma maior quantidade de exopolissacarídeo piruvatado do que as células cultivadas na sua ausência. Os dados de RPE indicaram que a quantidade de íons Cu2+ diminuiu com o tempo de cultura. Os dados de RMN de 13C mostraram a complexação dos íons de Cu2+ com o EPS. Esses resultados mostraram que o EPS tem um papel importante no mecanismo de proteção da Xac ao Cu2+ e este age no mecanismo inicial de proteção, ligando-se aos íons de Cu2+ livres, reduzindo sua difusão e o transporte ativo ao citoplasma . O Cu2+ também induz a produção de EPS piruvatado, que aumenta a capacidade de coleta e complexação desses íons.

We analyzed the role of exopolysaccharide in the Xanthomonas axonopodis pv. citri (Xac) Cu2+ resistance mechanism by Fourier transform infrared (FTIR), electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopies. The FTIR data show that cells cultivated in the presence of 0.2 mmol L-1 of CuSO4 produce larger amounts of pyruvated exopolissacharide (EPS) than the ones cultivated in its absence. The EPR data indicate that the amount of Cu2+ decreases with cultivation time. The 13C-CPMAS NMR data also show the complexation of Cu2+ ions to the EPS. The results demonstrate that EPS plays an important role in Xac Cu2+ protection. Both capsular and slime EPS act as an initial protection mechanism, binding free Cu2+ ions, reducing their diffusion and their active transport to the cytoplasm. Cu2+ also induces the production of a highly pyruvated negative EPS, increasing its capture and binding capacity.

The Steady-State Free Precession (SSFP) sequence has been widely used in low-field and low-resolution imaging NMR experiments to increase the signal-to-noise ratio (s/n) of the signals. Here, we analyzed the Scrambled Steady State - SSS and Unscrambled Steady State - USS sequences to suppress phase anomalies and sidebands of the 13C NMR spectrum acquired in the SSFP regime. The results showed that the application of the USS sequence allowed a uniform distribution of the time interval between pulses (Tp), in the established time range, allowing a greater suppression of phase anomalies and sidebands, when compared with the SSS sequence.

A aplicação do lodo de esgoto é utilizada como alternativa de conservação e manutenção da fertilidade dos solos sem prejudicar o ecossistema. O objetivo do presente trabalho foi avaliar a influência da aplicação de lodo de esgoto sobre a matéria orgânica (MO) de um Latossolo vermelho amarelo brasileiro, através da fluorescência induzida por laser (LIF). A LIF foi utilizada para analisar a fluorescência do solo intacto e suas frações químicas e físicas. Houve grande contribuição da fração humina à fluorescência do solo intacto, remarcando a importância de estudar a matéria orgânica (MO) associada à matriz mineral do solo. Para cada fração granulométrica foram obtidos espectros com diferentes perfis, indicando diferenças nos compostos orgânicos a elas ligados. A fração 2-20 µm, que apresentou maior conteúdo de carbono (~5%), representa somente 10% do solo mas acumula 34-39 % do conteúdo total de carbono do mesmo e mostrou a maior intensidade de fluorescência. O espectro desta fração mostra sua heterogeneidade e alta concentração de compostos cuja fluorescência é centrada nos 510 nm, o que indica alta concentração de sistemas com ligações insaturadas, com alto grau de ressonância e maior conjugação do sistema de eletrons pi, indicando maior aromaticidade quando comparado as outras frações. Não foram observadas diferenças significativas entre os tratamentos de lodo de esgoto. A LIF é uma técnica promissora para caraterizar a MO de solos intatos, permitindo estudar sua distribuição na matriz mineral do solo, inclusive nos Latossolos.

Sludge applications have been used to maintain fertility of agricultural soils without damaging the natural ecosystem. The aim of this study was evaluating the influence of sewage-sludge addition on the quality of organic matter (OM) of a Brazilian Oxisol by Laser Induced Fluorescence (LIF). LIF was used to analyze OM of whole soil and different soil fractions separated by chemical and physical methods. The high fluorescence contribution of humin fraction to the fluorescence of whole soils was shown, stressing the importance of studying OM associated to mineral matrix of soil. Spectra with different shapes were obtained for every particle size fraction, indicating differences in organic compounds bounded to them. The fraction with the higher carbon content was the 2-20 µm, that contains ~5% C and represents only 10% in soil, but stores 34-39 % of total C and shows the highest fluorescence intensity. The spectrum of this fraction shows its heterogeneity and a higher concentration of compounds which fluorescence is centered at 510 nm. This indicates a higher concentration of unsaturated bond systems capable of high degree of resonance, increased conjugation of the electron pi system, and higher aromaticity comparing with other fractions. No differences were detected for treatments of sewage-sludge applications. LIF spectroscopy is a promising technique for OM studies in whole soils, allowing to study spatial distribution of OM within the soil's mineral matrix, including Oxisols.