RESUMO
Invited for the cover of this issue are Jesús Ferrando-Soria, Donatella Armentano, Antonio Leyva-Pérez, Emilio Pardo and co-workers at University of Valencia, Technical University of Valencia and University of Calabria. The image depicts the crystal structure of a novel ZnII biological metal-organic framework that mimics ß-lactamase enzymes. Read the full text of the article at 10.1002/chem.202301325.
Assuntos
Biomimética , Estruturas Metalorgânicas , Humanos , Catálise , Penicilinas , beta-Lactamases , Antibacterianos , ZincoRESUMO
ß-Lactam antibiotics are one of the most commonly prescribed drugs to treat bacterial infections. However, their use has been somehow limited given the emergence of bacteria with resistance mechanisms, such as ß-lactamases, which inactivate them by degrading their four-membered ß-lactam rings. So, a total knowledge of the mechanisms governing the catalytic activity of ß-lactamases is required. Here, we report a novel Zn-based metal-organic framework (MOF, 1), possessing functional channels capable to accommodate and interact with antibiotics, which catalyze the selective hydrolysis of the penicillinic antibiotics amoxicillin and ceftriaxone. In particular, MOF 1 degrades, very efficiently, the four-membered ß-lactam ring of amoxicillin, acting as a ß-lactamase mimic, and expands the very limited number of MOFs capable to mimic catalytic enzymatic processes. Combined single-crystal X-ray diffraction (SCXRD) studies and density functional (DFT) calculations offer unique snapshots on the host-guest interactions established between amoxicillin and the functional channels of 1. This allows to propose a degradation mechanism based on the activation of a water molecule, promoted by a Zn-bridging hydroxyl group, concertedly to the nucleophilic attack to the carbonyl moiety and the cleaving of C-N bond of the lactam ring.
Assuntos
Estruturas Metalorgânicas , beta-Lactamases , beta-Lactamases/química , Penicilinas , Biomimética , Antibacterianos/química , beta-Lactamas , Catálise , Amoxicilina , Zinco/químicaRESUMO
Achieving a precise control of the final structure of metal-organic frameworks (MOFs) is necessary to obtain desired physical properties. Here, we describe how the use of a metalloligand design strategy and a judicious choice of ligands inspired from nature is a versatile approach to succeed in this challenging task. We report a new porous chiral MOF, with the formula Ca5II{CuII10[(S,S)-aspartamox]5}·160H2O (1), constructed from Cu2+ and Ca2+ ions and aspartic acid-decorated ligands, where biometal Cu2+ ions are bridged by the carboxylate groups of aspartic acid moieties. The structure of MOF 1 reveals an infinite network of basket-like cages, built by 10 crystallographically distinct Cu(II) metal ions and five aspartamox ligands acting as bricks of a tubular motif, composed of seven basket-like cages each. The pillared hepta-packed cages generate pseudo-rhombohedral nanosized channels of ca. 0.7 and 0.4 nm along the b and a crystallographic axes. This intricate porous 3D network is anionic and chiral, each cage displaying receptor properties toward three-nuclear [Ca3(µ-H2O)4(H2O)17]6+ entities. 1 represents the first example of an extended porous structure based on essential biometals Cu2+ and Ca2+ ions together with aspartic acid as amino acid. 1 shows good biocompatibility, making it a good candidate to be used as a drug carrier, and hydrolyzes in acid water. The hypothesis has been further supported by an adsorption experiment here reported, as a proof-of-principle study, using dopamine hydrochloride as a model drug to follow the encapsulation process. Results validate the potential ability of 1 to act as a drug carrier. Thus, these make this MOF one of the few examples of biocompatible and degradable porous solid carriers for eventual release of drugs in the stomach stimulated by gastric low pH.
Assuntos
Ácido Aspártico/química , Materiais Biocompatíveis/química , Estruturas Metalorgânicas/química , Materiais Biocompatíveis/síntese química , Humanos , Estruturas Metalorgânicas/síntese química , Modelos Moleculares , Estrutura Molecular , Células Tumorais CultivadasRESUMO
Citrus aurantium is a widespread tree in the Mediterranean area, and it is mainly used as rootstock for other citrus. In the present study, a vacuum infiltration centrifugation procedure, followed by solid phase extraction matrix-assisted laser desorption ionization tandem mass spectrometry (SPE MALDI MS/MS) analysis, was adopted to isolate proteins from leaves. The results of mass spectrometry (MS) profiling, combined with the top-down proteomics approach, allowed the identification of 78 proteins. The bioinformatic databases TargetP, SignalP, ChloroP, WallProtDB, and mGOASVM-Loc were used to predict the subcellular localization of the identified proteins. Among 78 identified proteins, 20 were targeted as secretory pathway proteins and 36 were predicted to be in cellular compartments including cytoplasm, nucleus, and cell membrane. The largest subcellular fraction was the secretory pathway, accounting for 25% of total proteins. Gene Ontology (GO) of Citrus sinensis was used to simplify the functional annotation of the proteins that were identified in the leaves. The Kyoto Encyclopedia of Genes and Genomes (KEGG) showed the enrichment of metabolic pathways including glutathione metabolism and biosynthesis of secondary metabolites, suggesting that the response to a range of environmental factors is the key processes in citrus leaves. Finally, the Lipase GDSL domain-containing protein GDSL esterase/lipase, which is involved in plant development and defense response, was for the first time identified and characterized in Citrus aurantium.
Assuntos
Citrus/química , Folhas de Planta/química , Proteínas de Plantas/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem , Sequência de Aminoácidos , Citrus/enzimologia , Citrus/genética , Biologia Computacional , Esterases/metabolismo , Genes de Plantas , Lipase/metabolismo , Proteínas de Plantas/química , Domínios Proteicos , Frações Subcelulares/metabolismoRESUMO
Extra virgin olive oil provides an important intake of α-tocopherol, which is part of vitamin E complex. A fast analytical method for its quantification, based on paper spray mass spectrometry, has been developed. The methodology possesses the ability to record mass spectra without sample preparation or preseparation steps. The experiments were performed in Multiple Reaction Monitoring scan mode; in particular, the transitions m/z 429 â m/z 163 for α-tocopherol and m/z 435 â m/z 169 for the labeled internal standard were monitored, in order to obtain the greatest specificity and the best sensitivity. The accuracy of the method was tested analyzing spiked samples prepared at concentrations within the dynamic range of the calibration curve, which returned values near 100%. Furthermore, good values of LOQ and LOD were obtained, demonstrating that this approach can be applied for a rapid screening of tocopherols in different vegetable oils. The results were compared with analyses performed by traditional chromatographic methods. Graphical abstract.
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Here, we show that a 2:1 mixture of Brutieridin and Melitidin, termed "BMF", has a statin-like properties, which blocks the action of the rate-limiting enzyme for mevalonate biosynthesis, namely HMGR (3-hydroxy-3-methylglutaryl-CoA-reductase). Moreover, our results indicate that BMF functionally inhibits several key characteristics of CSCs. More specifically, BMF effectively i) reduced ALDH activity, ii) blocked mammosphere formation and iii) inhibited the activation of CSC-associated signalling pathways (STAT1/3, Notch and Wnt/beta-catenin) targeting Rho-GDI-signalling. In addition, BMF metabolically inhibited mitochondrial respiration (OXPHOS) and fatty acid oxidation (FAO). Importantly, BMF did not show the same toxic side-effects in normal fibroblasts that were observed with statins. Lastly, we show that high expression of the mRNA species encoding HMGR is associated with poor clinical outcome in breast cancer patients, providing a potential companion diagnostic for BMF-directed personalized therapy.
Assuntos
Produtos Biológicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Hidroximetilglutaril-CoA Redutases/metabolismo , Ácido Mevalônico/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Óleos de Plantas/química , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico/metabolismo , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Metástase Neoplásica , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Prognóstico , Transdução de Sinais/efeitos dos fármacos , Taxa de SobrevidaRESUMO
A rapid and reliable method to assay the total amount of tyrosol and hydroxytyrosol derivatives in extra virgin olive oil has been developed. The methodology intends to establish the nutritional quality of this edible oil addressing recent international health claim legislations (the European Commission Regulation No. 432/2012) and changing the classification of extra virgin olive oil to the status of nutraceutical. The method is based on the use of high-performance liquid chromatography coupled with tandem mass spectrometry and labeled internal standards preceded by a fast hydrolysis reaction step performed through the aid of microwaves under acid conditions. The overall process is particularly time saving, much shorter than any methodology previously reported. The developed approach represents a mix of rapidity and accuracy whose values have been found near 100% on different fortified vegetable oils, while the RSD% values, calculated from repeatability and reproducibility experiments, are in all cases under 7%. Graphical abstract Schematic of the methodology applied to the determination of tyrosol and hydroxytyrosol ester conjugates.
Assuntos
Antioxidantes/análise , Cromatografia Líquida de Alta Pressão/métodos , Azeite de Oliva/análise , Álcool Feniletílico/análogos & derivados , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/economia , Análise de Alimentos/economia , Análise de Alimentos/métodos , Hidrólise , Limite de Detecção , Micro-Ondas , Álcool Feniletílico/análise , Espectrometria de Massas em Tandem/economiaRESUMO
A simple and fast method based on paper spray mass spectrometry for the determination of caffeine in commercial beverages and drugs has been developed; the analyses were carried out in MRM mode, monitoring the transitions m/z 195 â m/z 138 for caffeine and m/z 198 â m/z 140 for the labeled internal standard. To verify the reliability of the proposed approach, a spiked sample (soda drink and paracetamol tablet) with a known amount of caffeine has been prepared and analyzed by PS-MS, providing accuracy values about 100 %; the LOQ and LOD values were calculated at 1.2 and 1.6 µg/mL, respectively. Both beverages and drugs were also analyzed with the classic analytical method based on LC-UV measurements, showing consistent results between the two approaches, thus confirming the reliability of the developed ambient MS determination. Graphical Abstract The assay of caffeine by paper mass spectrometry.
Assuntos
Bebidas/análise , Cafeína/análise , Preparações Farmacêuticas/análise , Espectrometria de Massas em Tandem/métodos , Limite de Detecção , Padrões de Referência , Espectrofotometria UltravioletaRESUMO
A method for the determination and quantification of ketosteroid hormones in meat by mass spectrometry, based on the derivatization of the carbonyl moiety of steroids by O-methylhydroxylamine, is presented. The quantitative assay is performed by means of multiple-reaction-monitoring (MRM) scan mode and using the corresponding labelled species, obtained by reaction with d 3-methoxylamine, as internal standard. The accuracy of the method was established by evaluating artificially spiked samples, obtaining values in the range 90-110%. Recovery tests were performed on blank matrix samples spiked with non-natural steroids including trenbolone and melengestrol acetate. The latter experiment revealed that the yield of the extraction processes was approximately 60%. Good values of LOQ and LOD were achieved, making this method competitive with current hormone assay methods.
Assuntos
Cetosteroides/análise , Carne/análise , Espectrometria de Massas em Tandem/métodos , Cetosteroides/isolamento & purificação , Microextração em Fase SólidaRESUMO
A simple procedure is proposed for selective protein solubilization and trypsin digestion, followed by off-line liquid chromatography-matrix assisted laser desorption ionization mass spectrometry (LC-MALDI MS) analysis of Oenococcus oeni (O. oeni) bacterium. Peptides were identified from tryptic digests using sequencing by tandem mass spectrometry and database searches. Cytoplasmic and membrane related proteins (MRP) were identified in the O. oeni bacterium. MS/MS data analysis points out 13 peptides having one point mutation from 9 proteins. The major microheterogeneity was found for Zn-dependent alcohol dehydrogenase (Zn-ADH, Q04GE6) and 60 kDa chaperonin (GroEL, Q04E64) that are involved in methionine catabolism and post-translational protein folding, respectively. MS/MS data processing also leads to the identification of 34 unique phosphorylation sites from 19 phosphoproteins.
Assuntos
Proteínas de Bactérias/química , Oenococcus/metabolismo , Proteoma/química , Sequência de Aminoácidos , Proteínas de Bactérias/isolamento & purificação , Proteínas de Bactérias/metabolismo , Cromatografia Líquida de Alta Pressão , Dados de Sequência Molecular , Fosfoproteínas/isolamento & purificação , Fosfoproteínas/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Proteólise , Proteoma/isolamento & purificação , Proteoma/metabolismo , Proteômica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrometria de Massas em Tandem , Tripsina/química , Vinho/microbiologiaRESUMO
Turmeric and ginger are extensively employed as functional ingredients due to their high content of curcuminoids and gingerols, considered the key bioactive compounds found in these roots. In this study, we present an innovative and fast method for the assay of curcuminoids and gingerols in different foods containing the two spices, with the aim of monitoring the quality of products from a nutraceutical perspective. The proposed approach is based on paper spray tandem mass spectrometry coupled with the use of a labeled internal standard, which has permitted to achieve the best results in terms of specificity and accuracy. All the calculated analytical parameters were satisfactory; accuracy values are around 100% for all spiked samples and the precision data result lower than 15%. The protocol was applied to several real samples, and to demonstrate its robustness and reliability, the results were compared to those arising from the common liquid chromatographic method.
Assuntos
Curcuma , Álcoois Graxos , Espectrometria de Massas em Tandem , Zingiber officinale , Zingiber officinale/química , Curcuma/química , Espectrometria de Massas em Tandem/métodos , Álcoois Graxos/análise , Reprodutibilidade dos Testes , Limite de Detecção , Catecóis/análise , Análise de Alimentos/métodos , Curcumina/análise , Curcumina/análogos & derivados , PapelRESUMO
Background: Pure bergamot juice exerts lipid lowering effects in dyslipidemic subjects. It is unknown whether bergamot-based beverages exert similar effects in healthy subjects. Aim: To assess the effects, if any, of a bergamot-based beverage (BBB, bergamot juice ≤25%) on lipid, metabolic and inflammatory biomarkers. Methods: Forty-five healthy subjects were randomised 1 : 1 to BBB intake (400 mL day-1) (55.5%) or control (44.5%) for 12 weeks. Anthropometric (waist circumference, body mass index (BMI)) and clinical (blood pressure) parameters, blood samples (glucose, glycated haemoglobin, insulinemia, lipid profile, liver and renal function, inflammatory biomarkers) and 24-h urine for the analysis of (poly)phenol metabolites were collected at the baseline and at 12 weeks. Intakes of energy, nutrients and food groups were assessed by a 7-day dietary record. Results: Both groups exhibited a time-related significant decrease in total cholesterol (p = 0.02), fasting plasma glucose (p = 0.016), insulin (p = 0.034), BMI (p < 0.001) and waist circumference (p = 0.04), but with no significant between-arm difference. The urinary profile of metabolites from the BBB-derived (poly)phenols well discriminated the two study groups, documenting good compliance in the intervention arm. Notably, urinary bergamot 3-hydroxy-3-methylglutaryl (HMG) -containing flavanones or derived HMG-containing metabolites were not detectable. BBB was well tolerated and no adverse events were recorded. Conclusion: This first randomized controlled trial of BBB consumption in healthy subjects showed no effects of BBB on the cardiometabolic risk profile. BBB consumption is a safe nutritional adjunct in the context of a well balanced diet.
Assuntos
Biomarcadores , Glicemia , Lipídeos , Humanos , Masculino , Feminino , Adulto , Biomarcadores/sangue , Biomarcadores/urina , Pessoa de Meia-Idade , Glicemia/metabolismo , Lipídeos/sangue , Fatores de Risco Cardiometabólico , Voluntários Saudáveis , Adulto Jovem , Insulina/sangue , Sucos de Frutas e Vegetais , Índice de Massa Corporal , Inflamação , Circunferência da Cintura , Doenças Cardiovasculares/prevenção & controleRESUMO
The structural characterization of a new flavonoid from bergamot fruit (Citrus bergamia Risso) carrying the 3-hydroxy-3-methyl glutaryl (HMG) ester moiety has been accomplished, and its antioxidant ability was tested from a chemical point of view. The peculiarity of the new molecule, named peripolin, relies on the presence of the HMG chemical group linked to the sugar portion of neoeriocitrin; the structure was elucidated using both high-resolution mass spectrometry and nuclear magnetic resonance experiments performed on the purified molecule extracted from the fruit. The antioxidant ability of the new molecule was tested by classical chemical approaches, such as DPPH, ABTS and FRAP assays, and from a theoretical point of view. 1H and 13C NMR experiments and HR-ESI-MS/MS experiments show unequivocally that the HMG moiety is linked to the primary position of the glucose unit of neohesperidose, while the chemical tests and the computational results show that peripolin possesses strong antioxidant behavior, similar to that of neoeriocitrin and remarkably higher respect to the other flavonoids present in the fruit. Furthermore, the quantitative assays carried out by UPLC-MS/MS showed that its amount in the fruit is similar to that of the other main flavonoids. Furthermore, molecular dynamics simulations allowed us to investigate the possible conformations adopted by the antioxidants in the presence of water molecules. In particular, the switch of open-closed conformations of HMG-containing species was evidenced. As far as the reaction with DPPH, the calculation of ΔGrea supported the experimental outcomes regarding the peripolin and neoeriocitrin activity. In conclusion, bergamot fruit, already known for its potential to lower the level of blood cholesterol, has been proven to contain molecules such as neoeriocitrin and the newly characterized peripolin, which could have important in-vivo antioxidant characteristics.
RESUMO
Cold storage is used to extend peach commercial life, but can affect quality. Quality changes are assessed through the content of nutritionally relevant compounds, aroma, physical characters and/or sensorially. Here, six peach and nectarine cultivars were sampled at commercial harvest and after 7 days of 1 °C storage. A trained panel was used to evaluate sensorial characters, while carotenoids, phenolics, vitamin C, total sugars, and qualitative traits including firmness, titrable acidity and soluble solid content were integrated with volatile organic compound (VOC) analysis previously reported. The different analyses reveal interesting patterns of correlation, and the six cultivars responded differently to cold storage. Sensory parameters were correlated with 64 VOCs and seven intrinsic characters. Acidity, firmness, and 10 VOCs were strongly negatively correlated with harmony and sweetness, but positively correlated with bitterness, astringency, and crunchiness. In contrast, Brix, b-carotene, and six VOCs were positively correlated with harmony and sweetness.
RESUMO
The quality of extra virgin olive oil is associated with the presence of microcomponents whose healing effects have been proved in some special cases. The enzymatic hydrolysis of oleuropein and ligstroside, and of their demethylated analogues, affords four different pentanedialdehydes, and for one of which, 2-(4-hydroxyphenyl)ethyl (3S,4E)-4-formyl-3-(2-oxoethyl)hex-4-enoate, also known as oleocanthal, an anti-inflammatory effect was quite recently carefully assessed. Extra virgin olive oil is now worldwide considered as a functional food whose daily intake, as for the Mediterranean diet, helps consumers in keeping a constant level of nonsteroidal anti-inflammatory drug (NSAID) in the blood. The presence of these active principles provides, therefore, olive oil with an important added value. In the framework of the actions of the recently funded Agrifood Regional Center, which should coordinate the scientific research and production worlds, an absolute analytical method was developed for the mass spectrometric detection of the two most abundant NSAIDs, Tyr-OLPD and HTyr-OLPD (oleopentanedialdehydes (OLPDs) conjugated to p-hydroxyphenylethanol and 3,4-dihydroxyphenylethanol, respectively), by UHPLC-ESI-MS/MS.
Assuntos
Aldeídos/análise , Aldeídos/química , Cromatografia Líquida de Alta Pressão/métodos , Óleos de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/normas , Limite de Detecção , Azeite de Oliva , Padrões de Referência , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray/normas , Espectrometria de Massas em Tandem/normasRESUMO
A fast and accurate methodology for the quantification of the most abundant flavanone glycosides in citrus beverages has been developed. The approach relies on the use of paper spray mass spectrometry, which allows to record data in few minutes and without sample pre-treatment. The experiments have been carried out in Multiple Reaction Monitoring scan mode, in order to obtain the best specificity and sensitivity. The analytical parameters were all satisfactory. The results coming from the analysis of real samples were compared to the data obtained by the commonly used chromatographic method, proving the robustness of the proposed approach.
Assuntos
Bebidas/análise , Citrus/metabolismo , Glicosídeos/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão , Citrus/química , Flavanonas/química , Limite de Detecção , Papel , Espectrometria de Massas em Tandem/instrumentaçãoRESUMO
A new original process has been set-up to obtain hydroxytyrosol-enriched food by means of CO2 supercritical fluid extraction. The process is based on the direct adsorption of hydroxytyrosol on selected foodstuff (e.g., flour, whole-wheat flour, and sugar) when placed in contact with olive oil (which is known to contain this phenol) under controlled temperature and pressure conditions of supercritical CO2. The transfer of the nutraceutical to the foodstuff was initially evaluated using a fortified olive oil model and was then applied to commercial olive oil and foodstuff. The yield of the hydroxytyrosol transfer was demonstrated to be quantitative. In order to prove the suitability of the final products, hydroxytyrosol-enriched flour was used to prepare a bread roll, which maintained the nutraceutical characteristics after the cooking. Finally, DPPH based experiments were performed to prove the radical scavenging activity of the functionalized foodstuff.
RESUMO
The solid phase isobaric mass tagging (SPIMT) approach is presented for simultaneous protein quantitation and identification. The novelty of the SPIMT strategy relies on a CID-based differentiation of regioisomeric species for quantitation of tagged proteolytic peptides. SPIMTs are unlabeled mass-tagging reagents, which consist of a reporter group, a mass balance group, and a spacer with a amine-specific reactive group, able to be linked to any N-terminal peptide. Therefore SPIMT-linked peptides from a two-plex set appear as a single unresolved precursor ion in MS, whereas the reporter groups lead to quantitation signals of m/z 168.2 and 182.2 Da upon tandem mass spectrometry (MS/MS) analysis with matrix-assisted laser desorption time-of-flight/time-of-flight (MALDI TOF/TOF). This strategy allows ease protein identification by direct submission of MS and MS/MS data to the MASCOT database. SPIMT approach showed an excellent quantitation linearity, detecting any relative concentration differences of peptides in two solutions over a 5-fold concentration range without losing sequencing information. Therefore, SPIMTs are an attractive, simple, and low cost alternative for two-plex quantitation of proteins and offer possibilities of tuning the two-plex signal mass window by replacing the spacer.
Assuntos
Proteínas/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Espectrometria de Massas em Tandem/métodos , Sequência de Aminoácidos , Cromatografia Líquida/métodos , Glutationa/química , Peptídeos/análise , Peptídeos/química , Proteínas/química , Proteínas/metabolismo , Tripsina/metabolismoRESUMO
A rapid analytical method for the determination of phenylethanoids content in extra virgin olive oil has been developed. The method intends to address the European regulation EU 432/2012 on health claims, which allows to report on the front label of olive oil, the positive health effects due to the consumption of this food. The innovative method is based on paper spray tandem mass spectrometry using deuterated standards. It relies on a two-step analysis, needed to assess the free form of tyrosol and hydroxytyrosol and their ester conjugates after hydrolysis treatment. Different olive oil samples have been analyzed and the classical analytical parameters such as accuracy, LOQ and LOD were calculated from fortified samples. The good values of the latters show the reliability of the new approach, that limits the time of analysis and sample preparation to few minutes.
Assuntos
Técnicas de Diluição do Indicador/mortalidade , Azeite de Oliva/química , Álcool Feniletílico/análogos & derivados , Espectrometria de Massas em Tandem/métodos , Antioxidantes/química , Hidrólise , Álcool Feniletílico/químicaRESUMO
We report on a sensitive and fast quantitative MALDI-MS/MS method used to assess saffron authenticity by direct analysis through the determination of picrocrocin as the saffron authenticity marker, and using curcumin as the non-isotopic isobaric internal standard. The internal standard curcumin yielded good linearity (R2â¯=â¯0.994), and with confidence intervals at 95% for intercept. The detectable maximum adulteration percentage (99.0%) was estimated interpolating the limit of detection (LOD) for the isobaric internal standard in linear regression. The LOD was 47.63â¯ppm, and LOQ was 56.53â¯ppm. Good accuracy and precision were obtained for all concentrations. The capability of the MS approach to monitor analytes in a specific, selective fashion was used to obtain a semi-quantitative adulteration percentage and to establish the adulterant by additional experiments. The detection of gardecin and its derivatives in commercial samples indicated that Gardenia jasminoides Ellis was used as the adulterant.