Glaucia Braz Alcantara

NMR-Based Metabolomic Analysis of Huanglongbing-Asymptomatic and -Symptomatic Citrus Trees.

Huanglongbing (HLB) is one of the most severe diseases that affects citrus trees worldwide and is associated with the yet uncultured bacteria Candidatus Liberibacter spp. To assess the metabolomic differences between HLB-asymptomatic and -symptomatic tissues, extracts from leaf and root samples taken from a uniform 6-year-old commercial orchard of Valencia trees were subjected to nuclear magnetic resonance (NMR) and chemometrics. The results show that the symptomatic trees had higher sucrose content in their leaves and no variation in their roots. In addition, proline betaine and malate were detected in smaller amounts in the HLB-affected symptomatic leaves. The changes in metabolic processes of the plant in response to HLB are corroborated by the relationship between the bacterial levels and the metabolic profiles.

HR-MAS NMR metabolomics of 'Swingle' citrumelo rootstock genetically modified to overproduce proline.

The accumulation of proline is a typical physiological response to abiotic stresses in higher plants. ‘Swingle’ citrumelo, an important rootstock for citrus production, has been modified with a mutated Δ1‐pyrroline‐5‐carboxylate synthetase gene (VaP5CSF129A) linked to the cauliflower mosaic virus 35S promoter to induce the overproduction of free proline. This paper presents a comparative metabolomic study of nontransgenic versus transgenic ‘Swingle’ citrumelo plants with high endogenous proline. 1H high‐resolution magic angle spinning nuclear magnetic resonance spectroscopy and multivariate analysis showed significant differences in some metabolites between the nontransgenic and transgenic leaves and roots. The overproduction of proline has reduced the sucrose content in transgenic leaves, revealing a metabolic cost for these plants. In roots, the high level of free proline acts for the adjustment of cation–anion balance, causing the reduction of acetic acid content. The same sucrose level in roots indicates that they can be considered as sucrose sink. Similar behavior may be waited for fruits produced on transgenic rootstock. Copyright

Ethanol determination in frozen fruit pulps: an application of quantitative nuclear magnetic resonance

This study reports the chemical composition of five types of industrial frozen fruit pulps (acerola, cashew, grape, passion fruit and pineapple fruit pulps) and compares them with homemade pulps at two different stages of ripening. The fruit pulps were characterized by analyzing their metabolic profiles and determining their ethanol content using quantitative Nuclear Magnetic Resonance (qNMR). In addition, principal component analysis (PCA) was applied to extract more information from the NMR data. We detected ethanol in all industrial and homemade pulps; and acetic acid in cashew, grape and passion fruit industrial and homemade pulps. The ethanol content in some industrial pulps is above the level recommended by regulatory agencies and is near the levels of some post‐ripened homemade pulps. This study demonstrates that qNMR can be used to rapidly detect ethanol content in frozen fruit pulps and food derivatives. Copyright

Decomposition Dynamics of Typha angustifolia under Aerobic Conditions

The study of the Typha species has gained attention in tropical areas due to their rapid growth, nutrient release, and contribution to detritus in lakes. Analysis of the degradation of Typha angustifolia has shown that the first stage of decomposition is marked primarily by the release of soluble compounds, indicating that microorganisms have a minor influence at this stage. In subsequent stages, microorganisms act by degrading and consuming phenolic compounds and phosphorus. The remaining compounds form humic substances and are retained in the detritus. Thus, microorganisms significantly degrade organic matter, resulting in a two-fold increase in decomposition. Different forms of phosphorus could be detected in the remaining mass by 31P NMR (nuclear magnetic resonance). By comparing the 31P NMR data between the samples with and without the antibiotic, we can better understand the slow decomposition process of Typha angustifolia.

HR-MAS NMR for Rapid Identification of Illicit Substances in Tablets and Blotter Papers Seized by Police Department

Illicit substances found in blotter papers and tablets seized by police are traditionally identified and characterized from extracts of these materials. However, the procedures involved in extraction stages can result in artifacts and even contamination of the samples to be analyzed. On the other hand, high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) is a technique that requires no pretreatment steps, enabling direct analysis of the material, including the analysis of new illegal synthetic psychoactive substances. This study presents and discusses applications of the HR-MAS NMR in the analysis of tablets and blotter papers seized. Additional analysis in solution of the extracts of these materials was performed to compare the obtained spectral resolution signals. The results demonstrated that the HR-MAS NMR allowed the rapid identification of 3,4-methylenedioxy-N-methylcathinone (methylone), 4-methylmethcathinone (mephedrone), 2,5-dimethoxy-4-bromoamphetamine (DOB) and 2-(4-bromo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25B-NBOMe) in samples of tablets and blotter papers seized in Goias State, Brazil.

1H HR-MAS NMR and S180 cells: metabolite assignment and evaluation of pulse sequence

High resolution magic angle spinning 1H nuclear magnetic resonance spectroscopy (HR-MAS NMR) is a useful technique for evaluation of intact cells and tissues. However, optimal NMR parameters are crucial in obtaining reliable results. To identify the key steps for the optimization of HR-MAS NMR parameters, we assessed different pulse sequences and NMR parameters using sarcoma 180 (S180) cells. A complete assignment of the metabolites of S180 is given to assist future studies.

Qualitative and quantitative control of pediatric syrups using Nuclear Magnetic Resonance and chemometrics

Graphical abstract Figure. No Caption available. HighlightsThe 1H NMR was applied to qualitative and quantitative analyses of pediatric syrup.This approach allows identifying several added compounds.Some syrups presented both sugar and sweeteners, and high ethanol content.The governments must demand information of the amount of added compounds.Consumers must follow guidelines of amount of sugars and sweeteners intake. Abstract Several flavoring and sweetening agents added to excipient of pediatric syrups are not declared in the package leaflet. Therefore, the aim of this study was to develop a non‐target, simple, and precise method for qualitative and quantitative evaluation of pediatric syrups using NMR spectroscopy combined with chemometrics. This approach allowed the identification of several added compounds as citric acid, cyclamate, ethanol, glycerol, propylene glycol, saccharin, sorbitol, fructose, glucose, and sucrose. Among the sugared syrups, sucrose was the main carbohydrate with approximately 59.1%, and for sweetened syrups, glycerol with 25.5%. The ethanol was found with highest concentration of 4.0%, approximately. In addition, some syrups presented both sugar and sweetener, which is inconsistent according to the purpose of the addition. Consequently, institutional structures of countries as Brazil that are in charge of public health should put additional compliance pressure on pharmaceutical companies to clearly declare in package leaflet the presence and exact amount of the main compounds (at least) existent in the pediatric excipients.

Metabolic Study of Dioecy in Mauritia flexuosa: NMR-based and Chemometric Approaches: Metabolic Study of Dioecy in Mauritia flexuosa

INTRODUCTION Mauritia flexuosa is a dioecious species native to the Amazon, and the gender identification can currently be determined through the differentiation between female and male flowers in the first flowering. OBJECTIVES To identify variations in the metabolome profiles of pooled and individual samples of leaves from female and male plants of M. flexuosa in reproductive phase, and the plant in its vegetative phase, using two extraction systems. MATERIAL AND METHODS Extractions of leaves were separately conducted using deuterated water and methanol. The extracts were evaluated by NMR spectroscopy and chemometric methods. RESULTS Different NMR spectroscopic profiles were observed for females, males, and plants in the vegetative phase. Significant variations were found in the carbohydrate and fatty acid contents for the aqueous and methanolic extracts, respectively. Although principal component analysis (PCA) has not been efficient to distinguish the genders, orthogonal signal correction/partial least squares-discriminant analysis (OPLS-DA) was able to successfully differentiate male and female plants in the reproductive phase, independently on the sampling approach. For plants in the vegetative phase, OPLS-DA method from aqueous extracts of M. flexuosa leaves also distinguished female samples from the others and showed a small overlap between male and young plants, while the classification model was not able to be used for prediction. CONCLUSIONS NMR spectroscopy and chemometric-based approach was demonstrated to be useful in the metabolic study of dioecy in M. flexuosa. The extracts of the leaves allowed for differentiation between male and female plants; however, for plants in the vegetative phase, the identification of the gender was not effective. Copyright

NMR-based approach reveals seasonal metabolic changes in mate (Ilex paraguariensis A. St.-Hil.)

Ilex paraguariensis (mate) is a species native to South America and is widely consumed in countries such Argentina, Uruguay, Paraguay, and Brazil. Mate consumption is associated with several phytotherapeutic functions, in addition to its cultural and regional importance. However, the harvest period can affect the properties of the mate, due to variations in the constituent proportions, as a consequence of seasonal changes. In this work, we employed nuclear magnetic resonance and chemometrics to evaluate the chemical variations in leaf extracts of I. paraguariensis over the four seasons of the year. We found significant changes in the levels of glucose, myo‐inositol, caffeine, theobromine, and fatty acids. These changes can be related to resource allocation for the flowering period, or to responses to environmental stresses, such as temperature.

Ozonolysis of neem oil: preparation and characterization of potent antibacterial agents against multidrug resistant bacterial strains

Neem, Azadirachta indica A. Juss, is endowed with relevant biological properties and its oil contains unsaturated fatty acids that are susceptible to structural modification by oxidative processes such as ozonolysis to form peroxides. Therefore, the aim of this work was the synthesis, physicochemical characterization, study of thermal behavior, and evaluation of the antimicrobial potential of neem ozonated oils. The ozonolysis reaction was performed over different periods of time, in the presence or absence of water at an ozone concentration of 63 mg L−1 O3/O2. The samples were characterized by 1H and 13C NMR spectroscopy, acid and iodine values and, DSC and TG/DTG thermal analyses. Additionally, quantitative 1H NMR spectroscopy was a very successful and useful tool to determine the unsaturation degree of samples. The products showed excellent broad-spectrum antimicrobial activity in comparison to other ozonated oils reported in the literature, with an MIC of <0.5 mg mL−1 for standard E. faecalis and clinical vancomycin resistant E. faecium, 5.0 mg mL−1 for clinical multiresistant K. pneumoniae (KPC), 2 mg mL−1 for standard S. aureus, and 3 mg mL−1 for methicillin-resistant S. aureus (MRSA). This is the first report on the antimicrobial action of neem oil after the ozonation process. The ozonated neem oils were investigated for their cytotoxicity against two normal human cell lines (HaCaT and HCEC). And the results show the products possess low toxicity. Our studies suggest the compounds can find potential application in the treatment of chronic wounds and skin infections.