RESUMO
Vitamin B12 (VitB12) is a micronutrient and acts as a cofactor for fundamental biochemical reactions: the synthesis of succinyl-CoA from methylmalonyl-CoA and biotin, and the synthesis of methionine from folic acid and homocysteine. VitB12 deficiency can determine a wide range of diseases, including nervous system impairments. Although clinical evidence shows a direct role of VitB12 in neuronal homeostasis, the molecular mechanisms are yet to be characterized in depth. Earlier investigations focused on exploring the biochemical shifts resulting from a deficiency in the function of VitB12 as a coenzyme, while more recent studies propose a broader mechanism, encompassing changes at the molecular/cellular levels. Here, we explore existing study models employed to investigate the role of VitB12 in the nervous system, including the challenges inherent in replicating deficiency/supplementation in experimental settings. Moreover, we discuss the potential biochemical alterations and ensuing mechanisms that might be modified at the molecular/cellular level (such as epigenetic modifications or changes in lysosomal activity). We also address the role of VitB12 deficiency in initiating processes that contribute to nervous system deterioration, including ROS accumulation, inflammation, and demyelination. Consequently, a complex biological landscape emerges, requiring further investigative efforts to grasp the intricacies involved and identify potential therapeutic targets.
Assuntos
Depressores do Sistema Nervoso Central , Deficiência de Vitamina B 12 , Humanos , Vitamina B 12 , Modelos Biológicos , Biotina , Sistema NervosoRESUMO
BACKGROUND: Cauliflower (Brassica oleracea L.) and globe artichoke (Cynara scolymus L.) are vegetables with a high waste index mainly related to stems and leaves. In this study, enzymatic hydrolysates obtained from these wastes were proposed to be used as plant biostimulants. Life cycle assessment methodology was also applied to evaluate environmental performances related to cauliflower and artichoke byproducts. RESULTS: Hydrolysates (HYs) were chemically and biologically characterized. Amino acids, organic acids, amines, polyols, mineral elements, phenols, tannins, flavonoids and sulfur compounds were identified and quantified by means of NMR, inductively coupled plasma mass spectrometry and UV-visible analyses. Cauliflower leaf and flower HYs showed the highest concentration of free amino acids, whereas stems showed the highest concentration of Ca. Regarding artichoke, asparagine, glutamine and aspartic acid were exclusively detected in stems, whereas artichoke leaves showed the highest Mg and Mn levels together with the highest antioxidant activity. The HYs diluted in water were tested as biostimulants. The impacts of five concentrations of HYs (0.00, 0.28, 0.84, 2.52 and 7.56 g L-1) on seed germination and early seedling growth of crimson clover, alfalfa, durum wheat and corn were investigated. CONCLUSIONS: The application of artichoke biostimulant (0.28 g L-1) positively influenced the coefficient of velocity of germination in alfalfa, crimson clover and durum wheat, whereas cauliflower biostimulant significantly improved corn germination speed. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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The discovery of new bioactivities is closely related to the generation of novel scaffolds, and in the past few years different strategies have been proposed to obtain unknown architectures from the manipulation of known compounds. In the present study, we exploited a vintage photochemical approach for the discovery of an unexpected pathway of reactivity related to Δ1-3-oxo-pentacyclic triterpenic acids gaining access to a new class of natural-unnatural 5(10â1)abeo-pentacyclic triterpenic acids.
Assuntos
Triterpenos , Triterpenos Pentacíclicos/farmacologia , Triterpenos/farmacologia , Triterpenos/análise , Cromatografia Líquida de Alta PressãoRESUMO
Currently, the leaves of the hop plant (Humulus lupulus L.) are an unexploited and still little-investigated agricultural by-product. In our study, with the aim of exploring the metabolome of dried hop leaves (Chinook cultivar), a metabolomic approach was applied using multiple analytical tools such as SPME/GC-MS, GC-MS, PTR-ToF-MS, and NMR to identify the secondary metabolites. The obtained results showed the presence of a high number of components belonging to different chemical classes. In fact, thanks to the multi-methodological approach, volatile organic compounds (VOCs) with low molecular weight, terpenic compounds, fatty acids, sugars, amino acids, organic acids, and alcohols have been detected and identified. Among the revealed terpenes in the untreated matrix, the sesquiterpenes α-humulene, ß-caryophyllene, and α-copaene were the most abundant. Among the saturated and unsaturated fatty acids, palmitic and linolenic acids, respectively, were those with the highest relative percentages. Particularly relevant was the sugar content, where sucrose was the main exponent while glutamate and asparagine were the principal detected amino acids. Conversely, alcohols and organic acids were the least abundant compound classes, and xanthohumol was also identified in the methanolic extract.
Assuntos
Humulus , Metabolômica , Aminoácidos , Metaboloma , Ácido GlutâmicoRESUMO
The recovery of bioactive compounds from crop byproducts leads to a new perspective way of waste reutilization as a part of the circular economy. The present study aimed at an exhaustive metabolite profile characterization of globe artichoke and cauliflower byproducts (leaves, stalks, and florets for cauliflower only) as a prerequisite for their valorization and future implementations. The metabolite profile of aqueous and organic extracts of byproducts was analyzed using the NMR-based metabolomics approach. Free amino acids, organic acids, sugars, polyols, polyphenols, amines, glucosinolates, fatty acids, phospho- and galactolipids, sterols, and sesquiterpene lactones were identified and quantified. In particular, globe artichoke byproducts are a source of health-beneficial compounds including chiro-inositol (up to 10.1 mg/g), scyllo-inositol (up to 1.8 mg/g), sesquiterpene lactones (cynaropicrin, grosheimin, dehydrocynaropicrin, up to 45.5 mg/g in total), inulins, and chlorogenic acid (up to 7.5 mg/g), whereas cauliflower byproducts enclose bioactive sulfur-containing compounds S-methyl-L-cysteine S-oxide (methiin, up to 20.7 mg/g) and glucosinolates. A variable content of all metabolites was observed depending on the crop type (globe artichoke vs. cauliflower) and the plant part (leaves vs. stalks). The results here reported can be potentially used in different ways, including the formulation of new plant biostimulants and food supplements.
Assuntos
Cynara scolymus , Sesquiterpenos , Cynara scolymus/química , Fenóis/química , Conservação de Recursos Energéticos , Glucosinolatos/metabolismo , Lactonas/química , Sesquiterpenos/química , Extratos Vegetais/químicaRESUMO
Unambiguous identification of the components of a natural mixture remains a challenging and meticulous issue. Usually, different analytical techniques and laborious separation protocols are employed; nevertheless, in some cases, delicate and equivocal problems are hardly addressed by traditional methods. In this context, an original methodology for the analysis of natural samples consisting of recent mass spectrometry methods based on ion mobility (MS-IM) is proposed. As an example, a polar fraction obtained by the essential oil prepared from Senecio transiens, an endemic plant harvested on the Corsica Island, was selected for this study to show how IM-MS-based methods easily provide very useful insights suggesting the presence of two diastereomers. To unambiguously confirm this hypothesis and verify reliability of the IM-MS results, the purified compounds were further analysed by means of nuclear magnetic resonance (NMR) methodologies, allowing the structural elucidation and the identification of two new natural compounds, diastereomers of 4-acetoxy-5,9-dimethyl-3-(2-methylpropenyl)-2-oxabicyclo[4.4.0] dec-9-ene, reported here for the first time.
Assuntos
Óleos Voláteis , Senécio , Espectroscopia de Ressonância Magnética , Espectrometria de Massas/métodos , Óleos Voláteis/química , Reprodutibilidade dos Testes , Senécio/químicaRESUMO
In this review, the three different NMR-based approaches usually used to study foodstuffs are described, reporting specific examples. The first approach starts with the food of interest that can be investigated using different complementary NMR methodologies to obtain a comprehensive picture of food composition and structure; another approach starts with the specific problem related to a given food (frauds, safety, traceability, geographical and botanical origin, farming methods, food processing, maturation and ageing, etc.) that can be addressed by choosing the most suitable NMR methodology; finally, it is possible to start from a single NMR methodology, developing a broad range of applications to tackle common food-related challenges and different aspects related to foods.
Assuntos
Análise de Alimentos , Alimentos , Análise de Alimentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Imageamento por Ressonância Magnética , Manipulação de AlimentosRESUMO
Extra virgin olive oil (EVOO) is a high-quality product that has become one of the stars in the food fraud context in recent years. EVOO can encounter different types of fraud, from adulteration with cheaper oils to mislabeling, and for this reason, the assessment of its authenticity and traceability can be challenging. There are several officially recognized analytical methods for its authentication, but they are not able to unambiguously trace the geographical and botanical origin of EVOOs. The application of nuclear magnetic resonance (NMR) spectroscopy to EVOO is reviewed here as a reliable and rapid tool to verify different aspects of its adulteration, such as undeclared blends with cheaper oils and cultivar and geographical origin mislabeling. This technique makes it possible to use both targeted and untargeted approaches and to determine the olive oil metabolomic profile and the quantification of its constituents.
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Metabolômica , Óleos de Plantas , Fraude , Espectroscopia de Ressonância Magnética , Azeite de Oliva/análise , Azeite de Oliva/químicaRESUMO
Untargeted (NMR) and targeted (RP-HPLC-PDA-ESI-MSn, RP-HPLC-FD) analytical methodologies were used to determine the bioactive components of 19 tea samples, characterized by different production processes (common tea and GABA tea), degrees of fermentation (green and oolong teas), and harvesting season (autumn and spring). The combination of NMR data and a multivariate statistical approach led to a statistical model able to discriminate between GABA and non-GABA teas and green and oolong teas. Targeted analyses showed that green and GABA green teas had similar polyphenol and caffeine contents, but the GABA level was higher in GABA green teas than in regular green tea samples. GABA oolong teas showed lower contents of polyphenols, caffeine, and amino acids, and a higher content of GABA, in comparison with non-GABA oolong teas. In conclusion, the results of this study suggest that the healthy properties of teas, especially GABA teas, have to be evaluated via comprehensive metabolic profiling rather than only the GABA content.
Assuntos
Camellia sinensis/química , Chá/química , Aminoácidos/química , Cafeína/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia de Fase Reversa/métodos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Extratos Vegetais/química , Folhas de Planta/química , Polifenóis/químicaRESUMO
Cannabis sativa L. crops have been traditionally exploited as sources of fibers, nutrients, and bioactive phytochemicals of medical interest. In the present study, two terpene-rich organic extracts, namely FOJ and FOS, obtained from Felina 32 hemp inflorescences collected in June and September, respectively, have been studied for their in vitro anticancer properties. Particularly, their cytotoxicity was evaluated in different cancer cell lines, and the possible entourage effect between nonintoxicating phytocannabinoids (cannabidiol and cannabichromene) and caryophyllane sesquiterpenes (ß-caryophyllene, ß-caryophyllene oxide and α-humulene), as identified at GC/MS analysis, was characterized. Modulation of cannabinoid CB1 and CB2 receptors was studied as a mechanistic hypothesis. Results highlighted marked cytotoxic effects of FOJ, FOS, and pure compounds in triple negative breast cancer MDA-MB-468 cells, likely mediated by a CB2 receptor activation. Cannabidiol was the main cytotoxic constituent, although low levels of caryophyllane sesquiterpenes and cannabichromene induced potentiating effects; the presence in the extracts of unknown antagonistic compounds has been highlighted too. These results suggest an interest in Felina 32 hemp inflorescences as a source of bioactive phytocomplexes with anticancer properties and strengthen the importance of considering the possible involvement of minor terpenes, such as caryophyllane sesquiterpenes, in the entourage effect of hemp-based extracts.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Inflorescência/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Sesquiterpenos Policíclicos/farmacologia , Antineoplásicos Fitogênicos/química , Cannabis/química , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Humanos , Sesquiterpenos Monocíclicos/química , Sesquiterpenos Monocíclicos/farmacologia , Compostos Fitoquímicos/química , Extratos Vegetais/química , Sesquiterpenos Policíclicos/química , Receptor CB2 de Canabinoide/metabolismo , Neoplasias de Mama Triplo NegativasRESUMO
The chemical profile of the female inflorescence extracts from seven Cannabis sativa L. dioecious cultivars (Carmagnola, Fibranova, Eletta Campana, Antal, Tiborszallasi, Kompolti, and Tisza) was monitored at three harvesting stages (4, 14, and 30 September), reaching from the beginning of flowering to end of flowering/beginning of seed formation, using untargeted nuclear magnetic resonance (NMR) and targeted (ultra-high-performance liquid chromatography (UHPLC) and spectrophotometry) analyses. The tetrahydrocannabinol content was always below the legal limits (<0.6%) in all the analyzed samples. The NMR metabolite profile (sugars, organic acids, amino acids, and minor compounds) subjected to principal components analysis (PCA) showed a strong variability according to the harvesting stages: samples harvested in stage I were characterized by a high content of sucrose and myo-inositol, whereas the ones harvested in stage II showed high levels of succinic acid, alanine, valine, isoleucine, phenylalanine, and threonine. Samples harvested in stage III were characterized by high levels of glucose, fructose, choline, trigonelline, malic acid, formic acid, and some amino acids. The ratio between chlorophylls and carotenoids content indicated that all plants grew up exposed to the sun, the Eletta Campana cultivar having the highest pigment amount. Tiborszallasi cultivar showed the highest polyphenol content. The highest antioxidant activity was generally observed in stage II. All these results suggested that the Cannabis sativa L. inflorescences of each analyzed dioecious hemp cultivar presented a peculiar chemical profile affected by the harvesting stage. This information could be useful for producers and industries to harvest inflorescences in the appropriate stage to obtain samples with a peculiar chemical profile suitable for proper applications.
Assuntos
Cannabis/crescimento & desenvolvimento , Inflorescência/crescimento & desenvolvimento , Antioxidantes/análise , Canabinoides/análise , Itália , Espectroscopia de Ressonância Magnética , Metabolômica , Fenóis/análise , Compostos Fitoquímicos/análise , Pigmentos Biológicos/análise , Extratos Vegetais/química , Análise de Componente PrincipalRESUMO
The metabolite profile of fresh Goji berries from two cultivars, namely Big Lifeberry (BL) and Sweet Lifeberry (SL), grown in the Lazio region (Central Italy) and harvested at two different periods, August and October, corresponding at the beginning and the end of the maturation, was characterized by means of nuclear magnetic resonance (NMR) and electrospray ionization Fourier transform ion cyclotron resonance (ESI FT-ICR MS) methodologies. Several classes of compounds such as sugars, amino acids, organic acids, fatty acids, polyphenols, and terpenes were identified and quantified in hydroalcoholic and organic Bligh-Dyer extracts. Sweet Lifeberry extracts were characterized by a higher content of sucrose with respect to the Big Lifeberry ones and high levels of amino acids (glycine, betaine, proline) were observed in SL berries harvested in October. Spectrophotometric analysis of chlorophylls and total carotenoids was also carried out, showing a decrease of carotenoids during the time. These results can be useful not only to valorize local products but also to suggest the best harvesting period to obtain a product with a chemical composition suitable for specific industrial use. Finally, preliminary studies regarding both the chemical characterization of Goji leaves generally considered a waste product, and the biological activity of Big Lifeberry berries extracts was also investigated. Goji leaves showed a chemical profile rich in healthy compounds (polyphenols, flavonoids, etc.) confirming their promising use in the supplements/nutraceutical/cosmetic field. MG63 cells treated with Big Lifeberry berries extracts showed a decrease of iNOS, COX-2, IL-6, and IL-8 expression indicating their significant biological activity.
Assuntos
Antioxidantes/química , Lycium/química , Extratos Vegetais/química , Carotenoides/química , Ácidos Graxos/química , Frutas , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Metabolômica , Polifenóis/químicaRESUMO
The chemical composition of the inflorescences from four Cannabis sativa L. monoecious cultivars (Ferimon, Uso-31, Felina 32 and Fedora 17), recently introduced in the Lazio Region, was monitored over the season from June to September giving indications on their sensorial, pharmaceutical/nutraceutical proprieties. Both untargeted (NMR) and targeted (GC/MS, UHPLC, HPLC-PDA/FD and spectrophotometry) analyses were carried out to identify and quantify compounds of different classes (sugars, organic acids, amino acids, cannabinoids, terpenoids, phenols, tannins, flavonoids and biogenic amines). All cultivars in each harvesting period showed a THC content below the Italian legal limit, although in general THC content increased over the season. Citric acid, malic acid and glucose showed the highest content in the late flowering period, whereas the content of proline drastically decreased after June in all cultivars. Neophytadiene, nerolidol and chlorogenic acid were quantified only in Felina 32 cultivar, characterized also by a very high content of flavonoids, whereas alloaromadendrene and trans-cinnamic acid were detected only in Uso-31 cultivar. Naringenin and naringin were present only in Fedora 17 and Ferimon cultivars, respectively. Moreover, Ferimon had the highest concentration of biogenic amines, especially in July and August. Cadaverine was present in all cultivars but only in September. These results suggest that the chemical composition of Cannabis sativa L. inflorescences depends on the cultivar and on the harvesting period. Producers can use this information as a guide to obtain inflorescences with peculiar chemical characteristics according to the specific use.
Assuntos
Cannabis/química , Cannabis/crescimento & desenvolvimento , Inflorescência/química , Canabinoides/química , Cromatografia Líquida de Alta Pressão , Flavonoides/química , Flores/química , Cromatografia Gasosa-Espectrometria de Massas , Itália , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Desenvolvimento VegetalRESUMO
New pentanuclear porphyrazine complexes of formula [{Pd(CBT)2}4LM]· xH2O (L = tetrakis-2,3-[5,6-di(2-pyridyl)pyrazino]porphyrazinato anion, CBT = m-carborane-1-thiolate, and M = MgII(H2O), ZnII, PdII) were prepared in good yield as dark green hydrated amorphous solids by reaction of the respective pentanuclear species [(PdCl2)4LM] with m-carboran-1-thiol in CH3CN. Physicochemical characterization of the new species was carried out by elemental and thermogravimetric analysis along with IR and 1H/13C NMR measurements. UV-vis spectral characterization performed in DMSO, DMF, and pyridine solution provided information about the stability of the new homo/heteropentanuclear species and their tendency to undergo detachment of the peripheral Pd(CBT)2 groups. The data from NMR, UV-vis, and electrochemical experiments indicate that external coordination of the Pd(CBT)2 units to the mononuclear [LM] species affects only slightly the π electron distribution within the internal macrocyclic choromophore. The Pd(CBT)2 units are released in pyridine solution and in the case of the ZnII complex [{Pd(CBT)2}4LZn] give rise to a finely crystalline light-yellow solid identified by single-crystal X-ray work as the trans isomer of the bispyridine adduct [py2(CBT)2Pd]. The new pentanuclear macrocyclic complexes behave in DMF solution as active photosensitizers for singlet oxygen production, 1O2, the cytotoxic agent in anticancer photodynamic therapy, and have larger quantum yield values (ΦΔ = 0.6-0.7) than those found on average for the related tetrapyrazinoporphyrazine analogs (ΦΔ = 0.4-0.6). The presence of the CBT groups in the currently investigated complexes opens up the possibility for their use in boron neutron capture therapy, leading potentially to new bimodal anticancer curative drugs.
Assuntos
Antineoplásicos/química , Metaloporfirinas/química , Porfirinas/química , Piridinas/química , Antineoplásicos/síntese química , Técnicas Eletroquímicas , Fluorescência , Metaloporfirinas/síntese química , Modelos Moleculares , Estrutura Molecular , Porfirinas/síntese química , Oxigênio Singlete/químicaRESUMO
Due to renewed interest in the cultivation and production of Italian Cannabis sativa L., we proposed a multi-methodological approach to explore chemically and biologically both the essential oil and the aromatic water of this plant. We reported the chemical composition in terms of cannabinoid content, volatile component, phenolic and flavonoid pattern, and color characteristics. Then, we demonstrated the ethnopharmacological relevance of this plant cultivated in Italy as a source of antioxidant compounds toward a large panel of enzymes (pancreatic lipase, α-amylase, α-glucosidase, and cholinesterases) and selected clinically relevant, multidrug-sensible, and multidrug-resistant microbial strains (Staphylococcus aureus, Helicobacter pylori, Candida, and Malassezia spp.), evaluating the cytotoxic effects against normal and malignant cell lines. Preliminary in vivo cytotoxicity was also performed on Galleria mellonella larvae. The results corroborate the use of this natural product as a rich source of important biologically active molecules with particular emphasis on the role exerted by naringenin, one of the most important secondary metabolites.
Assuntos
Cannabis/química , Flavonoides/química , Flavonoides/farmacologia , Óleos Voláteis/análise , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Células CACO-2 , Linhagem Celular Tumoral , Etnofarmacologia , Humanos , Itália , Células MCF-7 , Testes de Sensibilidade Microbiana , Óleos Voláteis/farmacologia , Fenóis/química , Fenóis/farmacologia , Plâncton/efeitos dos fármacosRESUMO
The nuclear magnetic resonance (NMR)-based metabolomic approach was used as analytical methodology to study the urine samples of chronic inflammatory rheumatic disease (CIRD) patients. The urine samples of CIRD patients were compared to the ones of both healthy subjects and patients with multiple sclerosis (MS), another immuno-mediated disease. Urine samples collected from 39 CIRD patients, 25 healthy subjects, and 26 MS patients were analyzed using 1H NMR spectroscopy, and the NMR spectra were examined using partial least squares-discriminant analysis (PLS-DA). PLS-DA models were validated by a double cross-validation procedure and randomization tests. Clear discriminations between CIRD patients and healthy controls (average diagnostic accuracy 83.5 ± 1.9%) as well as between CIRD patients and MS patients (diagnostic accuracy 81.1 ± 1.9%) were obtained. Leucine, alanine, 3-hydroxyisobutyric acid, hippuric acid, citric acid, 3-hydroxyisovaleric acid, and creatinine contributed to the discrimination; all of them being in a lower concentration in CIRD patients as compared to controls or to MS patients. The application of NMR metabolomics to study these still poorly understood diseases can be useful to better clarify the pathologic mechanisms; moreover, as a holistic approach, it allowed the detection of, by means of anomalous metabolic traits, the presence of other pathologies or pharmaceutical treatments not directly connected to CIRDs, giving comprehensive information on the general health state of individuals. Graphical abstract NMR-based metabolomic approach as a tool to study urine samples in CIRD patients with respect to MS patients and healthy controls.
Assuntos
Espectroscopia de Ressonância Magnética/métodos , Metabolômica , Doenças Reumáticas/urina , Adulto , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/urinaRESUMO
An NMR and chemometric analytical approach to classify beers according to their brand identity was developed within the European TRACE project (FP6-2003-FOOD-2-A, contract number: 0060942). Rochefort 8 Trappist beers (47 samples), other Trappist beers (76 samples) and non-Trappist beers (110 samples) were analyzed by 1 H NMR spectroscopy. Selected NMR signals were measured and used to build classification models. Three different classification problems were identified, namely Trappist versus non-Trappist, Rochefort versus Non-Rochefort, and Rochefort 8 versus non-Rochefort 8. In all the three cases, both a discriminant and a modeling approaches were followed, using partial least squares discriminant analysis (PLS-DA) and soft independent modeling of class analogies (SIMCA), respectively, leading to very high classification accuracy as evaluated by external validation. Information regarding chemical composition was also obtained: Trappist beers contain a higher amount of formic and pyruvic acids and a lower amount of acetic acid and alanine with respect to non-Trappist ones. Rochefort beers turned out to have also a higher content of propanol and isopentanol with respect to non-Rochefort samples. Finally, Rochefort 8, shows the highest content of pyruvic acid and the lowest content of gallic, fumaric, acetic acids, adenosine, uridine, 2-phenylethanol, GABA, and alanine.
Assuntos
Cerveja/análise , Cerveja/classificação , Análise de Alimentos/métodos , Espectroscopia de Ressonância Magnética/métodos , Análise Discriminante , Análise dos Mínimos Quadrados , Modelos Químicos , Compostos Orgânicos/análise , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Three new and easily accessible chiral compounds, containing the pharmacophore 1,3,4-thiadiazoline nucleus joined by a spiro center to a monoalkyl (methyl or t-butyl) substituted cyclohexyl fragment, have been synthesized and fully characterized from the structural and stereochemical point of view. The formation of a spiro-cyclohexyl-thiadiazoline system (sCT) offered the rare opportunity to generate at room temperature both anancomeric structures, displaying alkyl groups bound to the cyclohexyl ring in equatorial position, and other quite stable stereoisomers in which the same alkyl moieties are, instead, inserted in axial position, even for the extreme case represented by the really bulky t-butyl group. DFT calculations led to a clear rationalization of such stereochemical behaviors, pointing out that in all cases they arise from the unexpected strong anancomeric character possessed by the sCT framework in its 4-acetyl substituted version. In consideration of the large number of substances in which the 1,3,4-thiadiazoline heterocycle has been found as the active pharmacophore, the results discussed in this work may provide solid bases to allow a rational design of new chiral bioactive spiro-thiadiazolines characterized by well-defined stereochemical structures and single anancomeric geometries.
RESUMO
In this review, fundamental aspects of the untargeted NMR-based methodology applied to fruit characterization are described. The strategy to perform the structure elucidation of fruit metabolites is discussed with some examples of spectral assignments by 2D experiments. Primary ubiquitous metabolites as well as secondary species-specific metabolites, identified in different fruits using an untargeted 1H-NMR approach, are summarized in a comprehensive way. Crucial aspects regarding the quantitative elaboration of spectral data are also discussed. The usefulness of the NMR-based metabolic profiling was highlighted using some results regarding quality, adulteration, varieties and geographical origin of fruits and fruit-derived products such as juices.
Assuntos
Frutas/metabolismo , Espectroscopia de Ressonância Magnética/métodos , MetabolomaRESUMO
An NMR analytical protocol based on complementary high and low field measurements is proposed for blueberry characterization. Untargeted NMR metabolite profiling of blueberries aqueous and organic extracts as well as targeted NMR analysis focused on anthocyanins and other phenols are reported. Bligh-Dyer and microwave-assisted extractions were carried out and compared showing a better recovery of lipidic fraction in the case of microwave procedure. Water-soluble metabolites belonging to different classes such as sugars, amino acids, organic acids, and phenolic compounds, as well as metabolites soluble in organic solvent such as triglycerides, sterols, and fatty acids, were identified. Five anthocyanins (malvidin-3-glucoside, malvidin-3-galactoside, delphinidin-3-glucoside, delphinidin-3-galactoside, and petunidin-3-glucoside) and 3-O-α-l-rhamnopyranosyl quercetin were identified in solid phase extract. The water status of fresh and withered blueberries was monitored by portable NMR and fast-field cycling NMR. (1) H depth profiles, T2 transverse relaxation times and dispersion profiles were found to be sensitive to the withering.