This study reports the isolation and structural characterization of ravenelin (RVL) and ravenelin B (RVL B), a novel xanthone derivative produced by the endophytic fungus Exserohilum rostratum from the Brazilian Amazon. The compound was obtained in minute quantities with partial purity, presenting significant challenges for traditional structural characterization. Through the combined application of NMR spectroscopy (1D/2D) and DFT/GIAO calculations, we achieved unequivocal structural determination, demonstrating an effective strategy for investigating scarce natural products. Extensive computational analysis revealed key insights into the molecular properties: RVL B exhibits a predominantly locally excited character (61 δ ) values, and coupling constants (J) are given in Hertz (Hz). Concerning theoretical methods, all molecular optimizations and NMR calculations were performed within the DFT/GIAO framework using ω B97X-D/6-311++G(d, p). When necessary, the solvent was accounted for by the integral equation formalism of the polarizable continuum model. The electronic excitations of the ground and first excited state, as well as two-photon absorption cross-sections, were calculated within the TD-DFT framework by using different degrees of Hartree-Fock exchange (CAM-B3LYP, ω B97X-D, and M06-2H), also associated with the Pople 6-311++G(d, p) basis set and the continuum model of solvation.

In this study, we combined Hydrogen Nuclear Magnetic Resonance (1H NMR) and carbon isotope analysis to investigate honey fraud, focusing on a real case involving Brazilian producers. The adulteration methods identified included the use of partially Inverted Sugar derived from sugarcane, a thickening gel primarily composed of Maltodextrin, and artificial colorants. Carbon isotope analysis was employed to estimate the proportion of carbon from C4 sources, which is indicative of sugarcane adulteration. Out of 75 seized samples, 65 were found to be adulterated. In these cases, the amount of inverted sugar from sugarcane exceeded 65 %, and in many instances, reached 100 %, indicating that the final product contained no honey at all. 1H NMR analysis further revealed that the adulterated samples had a simpler composition compared to reference samples, primarily detecting alpha,beta-glucose, Fructose, and Sucrose, with Sucrose being the most significant compound for distinguishing adulterated from pure honey samples in the PCA. Additionally, the PCA analysis clearly differentiated pure honey from adulterated samples, revealing three distinct clusters of adulterated samples, which suggests the presence of different sources of adulterants. Thus, the combination of these analytical techniques proved effective in detecting honey adulteration, providing critical tools for combating the growing issue of fraud in the honey industry, which directly affects the health and economy of the population.

Ten anhydrous rare-earth (RE) chloride solvates were prepared by dehydration of RECl3·6H2O with triethylorthoformate (teof) in O-donor solvents as an accessible and general synthetic route. Reactions are quick, safe, mild, easily reproducible, and cost-effective. They run at room temperature or under reflux to give high-yield, pure crystalline products that are either new, such as [Gd2Cl4(μ-Cl)2(PriOH)6] (1) and [{GdCl(μ-Cl)2(thf)2}∞] (2), or obtained for the first time from teof, such as [GdCl3(thf)4] (3), trans-[MCl2(thf)5]trans-[MCl4(thf)2], M = Gd (4), Dy (6), and Y (7), [YbCl3(thf)3] (8), and [MCl3(dme)2], M = Gd (5), Dy (9), and Er (10). Structural and spectroscopic characterization is presented for all products, and variable-temperature magnetic susceptibility data are discussed for the Dy3+ complexes 6 and 9. The latter behaves as a field-induced single-ion magnet for which theoretical (ab initio) and experimental data allowed a non-trivial assignment of overlapping high- (Orbach, Ueff 139 cm-1) and low-temperature (Raman, weff 46.8(2) cm-1) magnetic relaxation mechanisms (1 kOe field). Besides the main products, unanticipated Lewis and redox reactivity led to serendipitous 11, [({Gd3Cl4(μ-Cl)4(μ-H3CCOO)(C3H8O2)(PriOH)4}·PriOH)∞], and 12, [{(thf)2Cl2Gd(μ-Cl)2(μ3-O2)Gd(thf)3}2]·3thf, whose formation is discussed. The final RE3+ anhydrous complexes serve as valuable starting materials for numerous substitution reactions in coordination and organometallic chemistry.

Essential oils are a complex matrix of volatile compounds produced by many plants of different families with diverse bioactivities. Eugenia uniflora (Myrtaceae), popularly known as the pitangueira, is native to Brazil and a source of essential oils, mainly composed of sesquiterpenes such as Furanodiene. Curzerene is the major contributor to most of the bioactive properties assigned to E. uniflora. Gas chromatography (GC) is the primary technique for characterizing essential oils. However, sesquiterpenes of the germacrene type may undergo a [3,3]-sigmatropic rearrangement in GC, converting into Elemene-type, leading to these compounds' misidentification. Curzerene is an Elemene-type compound known to result from the sigmatropic rearrangement of furanodiene. Aiming to demonstrate this evidence, the objective of this study was to perform a thermal treatment of the essential oil from E. uniflora, to simulate the heating conditions during GC to identify the chemical transformations in this essential oil. Essential oil from E. uniflora leaves were obtained by hidrodistillation and was characterized by GC-MS. Nine major sesquiterpenes were identified in the GC-MS analysis of the oil, with the most prevalent being Germacrene B (16.19%), Curzerene (13.28%), and Germacrene D (12.64%). Additionally, β-Elemene and β-Elemenone were identified in lower concentrations. In the NMR analysis, it was possible to identify only four germacrene-type compounds and a small amount of Curzerene. After thermal treatment (240 °C), the Elemenes resulting from the sigmatropic rearrangement were identified. These results suggest that most of the properties assigned to Curzerene throughout the years, which do not combine cold techniques, such as NMR spectroscopy, to characterize the essential oil of E. uniflora, were incorrectly assigned and likely belong to furanodiene, evidencing the importance of apply different methods of analysis in some situations.

A sustainable hydrogen source is essential for improving the environmental performance of industries that are heavily reliant on hydrogen. Transitioning from commercial hydrogen to cleaner sources is vital for reducing fossil fuel dependence. This study investigated the technical feasibility of a more environmentally friendly hydrogenation method for acid oils using in situ hydrogen generation. This approach uses sustainable ethanol under supercritical conditions combined with cost‐effective zinc oxidation in an aqueous medium. The technology enhances environmental sustainability while improving safety, storage, and transportation, offering significant economic advantages. The process also produces zinc oxide, a value‐added material, widely used industrially and typically priced at about 10% higher than metallic zinc. Various strategies optimized hydrogen production by enhancing both hydrogen generation and fatty acid hydrogenation. Using zinc, fatty acid saturation reached 55% at 220 °C, while near‐complete saturation (95%) was achieved at 280 °C with supercritical ethanol and a cost‐effective nickel catalyst. These findings highlight promising pathways for sustainable hydrogen production and hydrogenation using low‐cost catalysts, milder reaction conditions, and recyclable materials, supporting a circular economy.

A new luminescent molecular thermometer (LMT) was prepared, characterized, and investigated. The sensor works based on the temperature effect on the spin-crossover equilibrium between two spin states of a nickelcyclen derivative (cyclen = 1,4,7,10-tetraazacyclododecane) containing a naphthalene fragment as the emitting unit. DFT and TD- DFT calculations revealed that photoelectron transfer (PET) can partially quenches the fluorescence of the naphthalene fragment to varying degrees in both high- and low-spin states of the sensor. UV-visible spectra in coordinating solvents such as acetonitrile revealed that 80% of the predominant species adopt five-coordination in the triplet state ([Ni(cycna)(CH3CN)]2+) at 20 degrees C, while 20 % of the molecules are square planar in the singlet spin state. The fluorescence spectra showed excellent correlation of luminescence intensity with temperature (R2 = 1.00) from 10 to 70 degrees C, proving that the coordination compound can function as LMT.

Butter is among the most popular and commercially valuable dairy products. Its high commercial value makes it a major target for adulteration, which aims to reduce production costs by using lower-quality fats and oils from other sources. The annual global market is around USD 30 billion (2023), expected to reach USD 36 billion in 2028, which also justifies the enormous interest in adulteration. In this work, a confirmed case of butter adulteration was studied by Nuclear Magnetic Resonance (NMR) and Stable Carbon Isotopic Ratio Analysis (SCIRA) techniques, employed to detect the inclusion in butter production of vegetable oils, such as soybean and palm oils. A total of 21 samples seized by the Brazilian Federal Police were analysed by NMR and SCIR, and compared to original butter obtained from commercial sources. The composition of all the seized samples was a mixture of butter (dairy fat of animal origin) with fat of vegetable origin (soybean and palm oil) and did not contain milk as a major component. While NMR was an unequivocal choice to discriminate the chemical composition of food samples, identifying the short-chain saturated fatty acids present in milk fat, including the butyryl alkyl chain, SCIRA was able to discriminate the origin of fat present in the butter samples as C3 sources, such as palm vegetable oils.

IntroductionSome papers describe the presence of creatine in plants, based on a singlet signal at 3.02–3.05 ppm in the 1H NMR spectra. Although is there creatine in plants? Therefore, to answer this question, a comprehensive NMR investigation has been performed aiming the unambiguous assignment of the compound responsible for that signal.ObjectiveDetermine whether the compound behind the signal at 3.05 ppm is truly creatine or if it was just a misassignment, instead.MethodsSamples of leaves and cherries from Eugenia uniflora in their natural swollen state were submitted to HR-MAS NMR analysis.ResultsIt was found that the signal at 3.05 ppm was misassigned to creatine. The exhaustive NMR investigation revealed that the signal is related to the amino acid 4-hydroxy-N-methyl proline, instead.ConclusionThe comprehensive NMR investigation revealed that there is no creatine in plants, it was just a misassignment.

Fridericia chica is widely distributed in Brazil, where it is commonly known as crajiru or pariri in several regions. Despite its popular use for treating inflammations and as an insect repellent, there has been limited assessment of its chemical and biological properties, including its bioinsecticide activities. In this study, we conducted phytochemical analyses and investigated the larvicidal and repellent effects of F. chica against the mosquito Aedes aegypti. The F. chica (HEFc) hydroalcoholic extract was partitioned using column chromatography, and subfractions were analyzed using chromatographic and spectroscopic analyses (ESI-IT-MSn and NMR). In addition, HEFc was evaluated for its larvicidal and repellent activities. Phytochemical analyses revealed the presence of 17 constituents, including 2,4-dihydroxybenzoic and p-coumaric acids, along with umbelliferone, acetovanilone, myricetin-3-O-glucuronide, and cis-isorhapontigenin, which are reported for the first time in this species. Although no larvicidal effect was observed at the doses tested, the HEFc exhibited promising repellent effects against A. aegypti, which aligns with its ethnopharmacological potential. In addition, molecular docking studies demonstrated that the compounds of HEFc interacted efficiently with insect odorant binding proteins (OBPs), providing repellent effects. Consistent with the chemical profile and in silico studies, preparations of F. chica have considerable repellent potential.

Green tea is a product obtained from the processing of fresh leaves of Camellia sinensis (L.) O. Kuntze species. In this study, the influence of climatic parameters on the chemical composition of green tea cultivars ('Yabukita' and 'Yutakamidori') over the harvest was evaluated using HR-MAS NMR. 'Yabukita' showed higher concentrations of epicatechin while higher amounts of theanine and caffeine were found in 'Yutakamidori'. The decline of theanine was associated with high average maximum temperature and solar radiation index, this latter also seemed to be responsible for relevant changes in epicatechin concentrations. It was not possible to associate any trend between climatic parameters and caffeine concentration. Fluctuations in linolenic acid concentration were monitored during the harvest period and were associated with the plant's defense mechanism. Monitoring of green tea over seasons and correlating the fluctuations of compounds to climatic parameters might become an efficient strategy for establishing quality standards for green teas.

The potential for substantial economic gain, counterfeiting of branded spirits is becoming more and more prevalent and become a worldwide chronic problem, since it is not trivial to organoleptically detect counterfeit spirits by consumers. In addition to endangering consumers' health, by the presence of dangerous chemicals, counterfeit spirits market is imposing significant financial liability for the genuine suppliers as well as constitute in substantial loss of revenue for governments. The counterfeiting dynamics, the hardship of detecting counterfeit spirits, and the difficulty in using the available analytical methods may result in delays on the reports, inconclusive results, and lack of proof of the materiality of the crime. Counterfeiting process generally take places by refilling bottles of brand spirits with cheaper ones or even produced by counterfeiters and then resealing with the same authentic bottle caps. Fortunately, this practice can leave traces of evidence in bottle caps, which could be used to identify counterfeit spirits. This work shows that Infrared Spectroscopy and TimeDomain Nuclear Magnetic Resonance can be used to identify counterfeit spirits based on the analysis of its bottle caps, being valuable tools in the battle against counterfeit product market.

The receptivity of NMR spectroscopy is low when compared to other techniques. Historically, increasing the strength of the static magnetic field has been the major approach to increase NMR sensitivity. In recent years several polarization transfer protocols have been used to enhance the signal-to-noise ratio (SNR), although they require special accessories and/or sample preparation. In this paper, we consider both the challenges and opportunities of steady-state free precession (SSFP) pulse sequences as a simple and efficient alternative to enhance SNR, in standard high-resolution and benchtop low-resolution NMR spectrometers. The maximum gain in these sequences is obtained with the shortest time between the pulses (Tp). However, when Tp

Cooking is essential for preparing starch-based food, however thermal treatment promotes the complexation of biopolymers, impacting their final properties. Comprehensive Multiphase (CMP) NMR allows all phases (liquids, gels, and solids) to be differentiated and monitored within intact samples. This study acts as a proof-of-principle to introduce CMP-NMR to food research and demonstrate its application to monitor the various phases in spaghetti, black turtle beans, and white long-grain rice, and how they change during the cooking process. When uncooked, only a small fraction of lipids and structurally bound water show any molecular mobility. Once cooked, little “crystalline solid” material is left, and all components exhibit increased molecular dynamics. Upon cooking, the solid-like components in spaghetti contains signals consistent with cellulose that were buried beneath the starches in the uncooked product. Thus, CMP-NMR holds potential for the study of food and related processes involving phase changes such as growth, manufacturing, and composting.

The international public health emergency related to COVID-19 caused by the SARS-CoV-2 virus has altered several production and registration criteria for sanitary products, including alcohol-based hand sanitizers. In this work, we investigate the concentration of alcohol in sanitizers presented in gel form applying the principal component regression method on measurements using Infrared and Raman spectroscopic methods. The chemometric calibration is performed using isopropanol or ethanol as active agents, and the method is used to characterize several commercial samples. Furthermore, the results of the prediction of alcohol concentration, obtained by applying the principal component regression and partial least squares methods, in the spectroscopic techniques, were compared with each other and with the results provided by nuclear magnetic resonance. Our results show that spectroscopic techniques coupled with principal component regression are fast, low-cost, and safe tools for the determination of alcohol concentration, regardless the gelling agent used.

In this review, the disease and immunogenicity affected by COVID-19 vaccination at the metabolic level are described considering the use of nuclear magnetic resonance (NMR) spectroscopy for the analysis of different biological samples. Consistently, we explain how different biomarkers can be examined in the saliva, blood plasma/serum, bronchoalveolar-lavage fluid (BALF), semen, feces, urine, cerebrospinal fluid (CSF) and breast milk. For example, the proposed approach for the given samples can allow one to detect molecular biomarkers that can be relevant to disease and/or vaccine interference in a system metabolome. The analysis of the given biomaterials by NMR often produces complex chemical data which can be elucidated by multivariate statistical tools, such as PCA and PLS-DA/OPLS-DA methods. Moreover, this approach may aid to improve strategies that can be helpful in disease control and treatment management in the future.

This research characterizes key metabolites in the leaf from Citronella gongonha Martius (Mart.) Howard (Cardiopteridaceae). All metabolites were assessed in intact leaf tissue by proton ( 1 H) high-resolution magic angle spinning (HR-MAS) nuclear magnetic resonance (NMR) spectroscopy integrated with the principal component analysis (PCA) to depict molecular association with the seasonal change. The major ‘known unknown’ metabolites detected in 1 H HR-MAS NMR were derivatives of flavonoid, polyphenolic and monoterpenoid compounds such as kaempferol-3- O -dihexoside, caffeoyl glucoside ( 2 ), 3- O -caffeoylquinic acid ( 3 ), 5- O -caffeoylquinic acid ( 4 ), kingiside ( 5 ), 8-epi-kingisidic acid ( 6 ), (7 α )-7- O -methylmorroniside ( 7 ), (7 β )-7- O -methylmorroniside ( 8 ) and alpigenoside ( 9 ) together with the universally occurring sucrose ( 10 ), α -glucoses ( 11, 12 ), alanine ( 13 ), and fatty (linolenic) acid ( 14 ). Several of the major metabolites (1, 2–9) were additionally confirmed by liquid chromatography tandem mass spectrometry (LC–MS/MS). In regard with the PCA results, metabolites 1, 2–9 and 14 were influenced by seasonal variation and/or from further (a) biotic environmental conditions. The findings in this work indicate that C. gongonha Mart. is an effective medicinal plant by preserving particularly compounds 2, 3–9 in abundant amounts. Because of close susceptibility with seasonal shift and ecological trends, further longitudinal studies are needed to realize the physiology and mechanism involved in the production of these and new metabolites in this plant under controlled conditions. Also, future studies are recommended to classify different epimers, especially of the phenolics and monoterpenoids in the given plant.

In the present study, it was evaluated the chemical composition and the antinociceptive activity of the essential oil obtained from the leaves of Guatteria friesiana. Seven compounds corresponding to 96.2% of the crude essential oil were identified. The main components identified were the mixture of β-eudesmol and α-eudesmol (58.1%), and γ-eudesmol (16.8%). A new α-eudesmol derivative, named 5-hydroxy-α-eudesmol, was isolated together with the known compounds β-eudesmol and a mixture of α-eudesmol, β-eudesmol and γ-eudesmol of the essential oil. The chemical structures were determined by 1D and 2D NMR, and MS experiments. Essential oil has significant antinociceptive properties, which are related probably with the involvement of the opioid receptors and K+-ATP channels.

In the no-tillage system, soils generally exhibit some degree of compaction that limits agricultural production. In this scenario, the use of soil cover plants is one of the alternatives capable of improving the structural quality of the soil and increasing the productivity of crops, such as soybeans. In the context, the objective of this study was to evaluate the effect of plant cover species and management systems on the improvement of the physical characteristics of a Oxisol and its effects on the production and content of soybean oil. The treatments consisted of control, no-tillage system with gypsum, chiseling system, and 12 treatments with soil cover species composed of 6 summer species and 6 winter species, in completely randomized design. Soil samples were collected in the 0-0.1; 0.1-0.2 and 0.2-0.3 m layers for determination of bulk density (BD), total porosity (TP), microporosity, macroporosity, and saturated soil hydraulic conductivity (Ksat) in 2014, 2017, 2018. Grain yield, oil content, thousand-seed weight, mean plant height and number of plants per meter were evaluated in soybean crop. Mean treatment values were compared by Tukey’s test at 5% significance. Five months after the chiseling system, there was no influence on BD. The treatments did not present differences six months after the application of gypsum. BD, TP, micro and macroporosity and Ksat were the variables most influenced by the periods of the year in the three soil layers. Grain yield, oil content, thousand-seed weight, plant height and number of plants per meter were influenced by the seasons.

Abstract Phytochemical investigation of the atemoya aerial parts was carried out by LC-MS-IT and cytotoxic activities were evaluated as well. These results led to the identification of a new N-oxide alkaloid (dehydroanomuricine-N-oxide) and eight other alkaloids: scoulerine, reticuline, isocorydine, norisocorydine, asimilobine, nornuciferine, anonaine, and liriodenine. The new alkaloid dehydroanomuricine-N-oxide and anomuricine were also isolated. The structures of these compounds were determined by spectroscopic and spectrometric techniques. The cytotoxic capacity of crude methanolic extract and the alkaloidal fraction were evaluated, showing moderate cytotoxicity. The isolation and identification of these alkaloids are an important contribution to the chemotaxonomy of the genus Annona and the Annonaceae family.