HPLC–DAD–ESI/MS

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Phenolic profile of Sercial and Tinta Negra Vitis vinifera L. grape skins by HPLC–DAD–ESI-MS

Phenolic profile of Sercial and Tinta Negra Vitis vinifera L. grape skins by HPLC–DAD–ESI-MS

from 3568 to 7770 mg/kg, and for Tinta Negra from 3147 to 13812 mg/kg. The TPC values decreased from véraison (day 0) to maturity (day 42), for Sercial, whereas for Tinta Negra an increase, from véraison (day 0) to maturity (day 35), was observed. In gen- eral, it is known that the TPC increases throughout grape ripening (Pérez-Magariño & González-San José, 2006). Although, in some cases, this tendency was not reported (Alonso Borbalán et al., 2003), as observed for Sercial. According to a previous study (Alon- so Borbalán et al., 2003), at the start of maturation, the grapes are smaller, the ratio of skins and seeds to the pulp is higher, with the phenolic compounds being therefore more concentrated. In fact, at véraison, Sercial grapes are smaller than Tinta Negra, but during ripening, their size increase is higher than that observed for Tinta Negra. The TPC values of Sercial, at véraison, were twofold higher than those found for Tinta Negra, whereas, at maturity, the TPC val- ues of Tinta Negra were fourfold higher than those of Sercial. TPC is a screening approach to estimate the total content of phenolics, however, as it does not give any detailed information about pheno- lic fraction, therefore, the phenolic profile was established by HPLCDADESI-MS n .
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Phlorotannin Extracts from Fucales Characterized by HPLC-DAD-ESI-MSn: Approaches to Hyaluronidase Inhibitory Capacity and Antioxidant Properties

Phlorotannin Extracts from Fucales Characterized by HPLC-DAD-ESI-MSn: Approaches to Hyaluronidase Inhibitory Capacity and Antioxidant Properties

Abstract: Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MS n . Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC 50 = 2.32 mg/mL dry weight)
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Contents lists available at ScienceDirect

Contents lists available at ScienceDirect

Given the increasing consumers demand for novelty, tea companies have been presenting new added value products such as reserve lots of aromatic plants. Herein, infusions from different lots of three aromatic plants were assessed in terms of phenolic composition (HPLC-DAD-ESI/MS) and antioxidant properties (reducing power, free radical scavenging and lipid peroxidation inhibition capacity). Cymbopogon citratus (C. citratus; main compound 5-O-caffeoylquinic acid) and Aloysia citrodora (A. citrodora; prevalence of verbascoside) reserve lots revealed higher phenolic compounds concentration than the respective standard lots. Thymus × citriodorus (T. citriodorus; main compound rosmarinic acid) standard lot presented higher amounts of phenolic acids than the reserve lot, nonetheless, total flavonoids and phenolic compounds were not significantly different. The differ- ences between both lots antioxidant activity were more noticeable in C. citratus, with the reserve lot presenting the highest activity. This study provides evidence of the differences between these plants chemical composition and bioactivity depending on the harvesting conditions.
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J. Braz. Chem. Soc.  vol.21 número12

J. Braz. Chem. Soc. vol.21 número12

A degradation system using metallic iron and hydrogen peroxide (Fenton reaction) was employed for the degradation of the diuron herbicide. In order to obtain the maximum degradation the main conditions such as pH, hydrogen peroxide concentration and iron amount, were optimized. Herbicide degradation was evaluated by liquid chromatography with diode array detection (HPLC-DAD) and liquid chromatography tandem mass spectrometric detection (LC-ESI-MS/MS) and total organic carbon analysis (TOC). In the best degradation condition, pH = 2.5, 2 g of iron and 2 mmol L -1 of hydrogen peroxide, after 10 min a commercial diuron solution (10 mg L -1 ) had
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Desenvolvimento de um método de screening para anfetaminas em urina empregando ESI-MS com confirmação por GC-MS.

Desenvolvimento de um método de screening para anfetaminas em urina empregando ESI-MS com confirmação por GC-MS.

Assim como na cromatografia a gás, a sensibilidade e a especificidade de um método de screening baseado em CLAE estão relacionadas ao tipo de detecção utilizado. Muitos equipamentos utilizam um detector de ultravioleta (HPLC-UV). Esse é considerado um detector universal, porém é pouco sensível, uma vez que várias substâncias absorvem energia com um mesmo comprimento de onda (BURROWS, 2005). O detector de arranjo de diodos (HPLC-DAD) permite a obtenção de um espectro completo de absorbância para o analito (LAI, 1997). Com esse tipo de detector, a sensibilidade do equipamento aumenta consideravelmente (SAARINEN, 1995). Outro detector utilizado é o de quimioluminescência (HPLC-CL). Por ser mais seletivo, o número de substâncias que se consegue detectar simultaneamente é limitado. No entanto, a sua sensibilidade é muito maior e em alguns casos consegue superar um CG-EM (TAKAYAMA, 1997). Assim como na cromatografia a gás, um dos detectores que permitem maior sensibilidade e seletividade para análises toxicológicas e de controle de dopagem é o Espectrômetro de Massas (HPLC-MS) (STANLEY, 2006). Quando esta técnica é utilizada, o uso de padrões de referência torna-se muitas vezes desnecessário, uma vez que existem bancos de dados de espectros de massa correspondentes às substâncias analisadas (DRESEN, 2006). Quando estes não existem, por meio de uma análise de massas seqüencial é possível obter o espectro de fragmentação do íon molecular do composto separado pela cromatografia e a partir dele chegar à estrutura química do composto (DEVENTER, 2006).
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J. Braz. Chem. Soc.  vol.21 número4

J. Braz. Chem. Soc. vol.21 número4

all pesticides. The calibration curves were linear over the whole concentration range tested for all pesticides under study with correlation coeficients (r) better than 0.998 as outlined in Table 3. The precision (repeatability) and the accuracy (recovery), obtained by analyzing in triplicate natural water samples spiked at three different levels for all pesticides under study, are outlined in Table 4. The precision obtained for the overall procedure was similar for both methods SPE and HPLC-DAD, and SPE and LC-ESI-MS/MS; remaining lower than 20%. Precision may have been mainly governed by the SPE step carried out prior to the chromatographic analysis. The recovery values of all compounds, for both methods, varied from 60.3 up to 108.9%. The values found are considered acceptable for chromatographic methods applied to pesticide residue determinations. 33
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Identification of some chemical constituents of Indigofera hirsuta Linn. (Fabaceae) by HPLC-ESI-MS (TOF) and evaluation of the antiradical activity.

Identification of some chemical constituents of Indigofera hirsuta Linn. (Fabaceae) by HPLC-ESI-MS (TOF) and evaluation of the antiradical activity.

os dados de UV e IV estão apresentados no material suplementar. Para conirmar a presença das substâncias nos respectivos ext. MeOH e extrato aquoso, as substâncias isoladas (1-6) e os extratos foram analisadas por CLAE-DAD-IES-EM (TOF). Esta análise permitiu combinar o tempo de retenção das substâncias com os dados de absorção no UV 29,30 (Figuras 1a e 1b).

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Detecção in silico e caracterização dos constituintes micromoleculares majoritários do fungo endofítico Colletotrichum gloeosporioides isolado de folhas de Garcinia xanthochymus usando HPLC-DAD-HRMS e GC-MS

Detecção in silico e caracterização dos constituintes micromoleculares majoritários do fungo endofítico Colletotrichum gloeosporioides isolado de folhas de Garcinia xanthochymus usando HPLC-DAD-HRMS e GC-MS

Entre as técnicas de ionização, a mais utilizada para o acoplamento com HPLC, devido à sua versatilidade, é a ESI (ionização por electrospray) (MATHIS and McCORD, 2004). ESI é um processo pelo qual, à pressão atmosférica, um campo elétrico intenso dispersa uma amostra líquida em um gás, que possui a forma de um fino spray de gotas carregadas que, por evaporação, resultam em íons na fase gasosa (CROTTI et al., 2006a; FENN, 2003). Esta técnica constitui um método brando, na qual pouca energia residual é retida pelo analito após a ionização, acarretando uma baixa fragmentação. Portanto, a reduzida transferência de energia para as moléculas é uma desvantagem desta técnica para estudos de elucidação estrutural. A fim de contornar essa desvantagem, foram desenvolvidos equipamentos de espectrometria de massas sequencial (MS/MS ou MS n ), na
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Phenolic profile in the quality control of walnut (Juglans regia L.) leaves

Phenolic profile in the quality control of walnut (Juglans regia L.) leaves

In Portugal, as in some other European countries, dry walnut leaves are still largely used as an infusion. Be- cause flavonoids and phenolic acids have already been successfully applied in the quality control of several foodstuffs (Andrade, Ferreres, & Amaral, 1997; And- rade, Leit ~ao, Seabra, Oliveira, & Ferreira, 1997; Areias, Valent ~ao, Andrade, Ferreres, & Seabra, 2001; Ramos et al., 1999; Silva et al., 2000), in the present work phen- olics of walnut leaves have been studied by HPLC/ DAD/MS/MSESI. A useful methodology for routine quality control, based on HPLC-DAD quantification of major phenolics was developed and applied to six dif- ferent cultivars growing under the same agricultural, geographical and climatic conditions. The evolution of phenolic compounds from May to September was also monitored.
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J. Braz. Chem. Soc.  vol.21 número8

J. Braz. Chem. Soc. vol.21 número8

Our previous research found that the crude extract of Neo-T. siphonanthun exhibited an effective DPPH (1,1-diphenyl-2-picryhydrazyl) radical scavenging activity. In this study an online rapid screening method, high-performance liquid chromatography-radical scavenging detection-diode array detector-electrospray ionization mass spectrometry (HPLC-RSD- DAD-ESI/MS) system, was developed for screening individual antioxidants from the most active fraction. Accordingly, three isomeric derivatives were detected. The target active compounds were isolated by high- speed counter-current chromatography (HSCCC) with the purity over 99%, and were identiied as luteolin-3’-O-β-D-glucopyranoside (1), luteolin-7-O-β-D-glucopyranoside (2) and luteolin-4’- O-β-D-glucopyranoside (3) by analysis of its off-line nuclear magnetic resonance (NMR) spectra. Antioxidant activity of three compounds was assessed by off-line DPPH assay, and all of them showed potent activity.
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Espectrometria de massas com ionização electrospray (ESI-MS) e métodos quimiométricos: caracterização de azeite de oliva (extra virgem e puro) e outros óleos vegetais e quantificação de óleos adulterantes em azeite de oliva extra virgem

Espectrometria de massas com ionização electrospray (ESI-MS) e métodos quimiométricos: caracterização de azeite de oliva (extra virgem e puro) e outros óleos vegetais e quantificação de óleos adulterantes em azeite de oliva extra virgem

Nos espectros de massas com ionização electrospray no modo positivo, ESI(+)- MS, das amostras dos azeites de oliva e demais óleos vegetais (soja, milho, girassol e canola) é possível se observar uma quantidade maior de sinais (cátions), embora nem todos tenham sido identificados. Os espectros ESI(+)-MS típicos dos azeites de oliva extra virgem e puro (Figuras 4.6 e 4.7, respectivamente), os quais apresentaram diferenças significativas contrariamente ao observado nos espectros ESI(-)-MS de tais amostras. Nos ESI(+)-MS pode-se observar os íons com m/z 121 e 137, os quais referem-se às formas protonadas dos compostos fenólicos tirosol e hidroxitirosol, respectivamente. [12] [15] O íon com m/z 417 refere-se à forma protonada do , – tocoferol, substância liposolúvel pertencente à família da vitamina E, comumente encontrada em vários tipos de azeite de oliva [50] .Este composto é encontrado nos óleos de soja, milho, girassol e canola [50]. No entanto, nos ESI(+)-MS de tais amostras (Figuras 4.8, 4.9, 4.10 e 4.11, respectivamente) não se observou a presença do íon com m/z 417.
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Estudo fitoquímico de extratos polares e infusão das folhas de Terminalia catappa L. (Combretaceae) e avaliação de suas atividades antiulcerogênica e mutagênica

Estudo fitoquímico de extratos polares e infusão das folhas de Terminalia catappa L. (Combretaceae) e avaliação de suas atividades antiulcerogênica e mutagênica

Di-O-galoil-β-D-glicose, HHDP-acetilglicosídeo, HHDP-hexosídeo, ácido elágico hexosídeo, ácido galágico e apigenina 8-C-(2’’-galoil)-β-D-glicopiranosil. Estes metabolitos foram confirmados por experimentos FIA-ESI-IT-MS n (Direct Flow Analysis-Electrospray ionization-Íon Trap-Tandem Mass Spectrometry) and High Performance Liquid Chromatography (HPLC) acoplada a arranjo de fotodiodos (PDA). Ácido elágico, ácido gálico e galato de metila foram confirmados por experimentos de co-injecção de padrão. Punicalagina foi detectada e isolada da fração hidrometanólica como uma mistura de anômeros e confirmada por experimentos de RMN 1 H e 13 C, mono e bidimensionais. O fracionamento da fração acetato proveniente do extrato hidroalcoólico por MPLC (Medium Pressure Liquid Chromatography) permitiu o isolamento dos metabólitos ácido galágico e apigenina 8-C-(2’’-galoil)-β-D-glicopiranosil. A configuração absoluta dos anômeros da punicalagina e do composto apigenina 8-C-(2’’-galoil)-β-D-glicopiranosideo foi estabelecida por experimentos de dicroísmo circular (DC). A determinação quantitativa dos principais metabolitos secundários foi realizada por HPLC-PDA, possibilitando, assim, a determinação da concentração e teor (%) de metabólitos presentes no extrato hidroalcoólico. Foram quantificados, pela primeira vez em extrato hidroalcoólico desta espécie, os metabólitos: punicalagina, ácido elágico, ácido gálico, galato de metila, ácido galágico e apigenina 8-C-(2’’-galoil)-β-D- glicopiranosil. A atividade antiulcerogênica foi avaliada no modelo de úlcera gástrica induzida por etanol absoluto em diferentes doses (25, 50 e 100 mg.Kg -1 ). A partir do fracionamento do extrato etanólico (IBB-UNESP-Botucatu), obteve-se três frações: hexânica , acetato de etila e aquosa. Foi constatado que as três frações apresentaram redução significativa na área de lesão. A fração aquosa apresentou diminuição significativa na dose de 25 mg.Kg -1 (42,61% de inibição). A atividade
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Analysis of pharmaceutical compounds in water by SPE-UPLC-ESI-MS/MS.

Analysis of pharmaceutical compounds in water by SPE-UPLC-ESI-MS/MS.

ANALYSIS OF PHARMACEUTICAL COMPOUNDS IN WATER BY SPE-UPLC-ESI-MS/MS. A method was developed for the analysis of 31 pharmaceutical compounds in Lisbon’s drinking water system, using solid-phase extraction (SPE) and ultra- performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The method was validated through estimation of the linearity range, method detection and quantification limits, matrix effects, precision and accuracy. The method detection and quantification limit ranges were 0.009-10 and 0.03-33 ng/L, respectively. Analytes were quantified in water samples collected from the EPAL (Empresa Portuguesa das Águas Livres S.A.) supply system. Carbamazepine, atenolol, sulfadiazine, sulfamethazine, sulfapyridine, sulfamethoxazole, acetaminophen, caffeine and erythromycin were quantified in the analysed samples.
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2-(4-IODINE-2,5-DIMETHOXYPHENYL)-N-[(2-METHOXYPHENYL)METHYL]ETAMINE OR 25I-NBOMe: CHEMICAL CHRACTERIZATION OF A DESIGNER DRUG.

2-(4-IODINE-2,5-DIMETHOXYPHENYL)-N-[(2-METHOXYPHENYL)METHYL]ETAMINE OR 25I-NBOMe: CHEMICAL CHRACTERIZATION OF A DESIGNER DRUG.

2-(4-IODINE-2,5-DIMETHOXYPHENYL)-N-[(2-METHOXYPHENYL)METHYL]ETAMINE OR 25I-NBOMe: CHEMICAL CHRACTERIZATION OF A DESIGNER DRUG. Drug traficking and the introduction of new drugs onto the illicit market are one of the main challenges of the forensic community. In this study, the chemical proile of a new designer drug, 2-(4-iodine-2,5- dimethoxyphenyl)-n-[(2-methoxyphenyl)methyl]etamine or 25I-NBOMe was explored using thin layer chromatography (TLC), ultraviolet-visible spectrophotometry (UV-Vis), attenuated total relection with Fourier transform infrared spectroscopy(ATR- FTIR), gas chromatography mass spectrometry (GC-MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). First, the TLC technique was effective for identifying spots related to 25C-, 25B- and 25I-NBOMe compounds, all with the same retention factor, Rf ≈ 0.50. No spot was detected for 2,5-dimethoxy-4-bromoamphetamine, 2,5-Dimethoxy-4-chloroamphetamine or lysergic acid diethylamide compounds. ATR-FTIR preserved the physical-chemical properties of the material, whereas GC-MS and ESI-MS showed better analytical selectivity. ESI(+)FT-ICR MS was used to identify the exact mass (m/z 428.1706 for the [M + H] + ion), molecular formula (M = C
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Reproducibility of an HPLC-ESI-MS/MS method for the measurement of stable-isotope enrichment of in vivo-labeled muscle ATP synthase beta subunit.

Reproducibility of an HPLC-ESI-MS/MS method for the measurement of stable-isotope enrichment of in vivo-labeled muscle ATP synthase beta subunit.

Initially, a full-scan spectrum was acquired followed by collision-induced dissociation mass spectra of the 10 most abundant ions in the survey scan to determine if there were b- F1-ATPase peptides with a high MS signal and a leucine residue in the sequence. No labeled-leucine peptides were detected in a data-dependent analysis, probably as a result of low abundance of stable-isotope-leucine enriched peptides in b-F1-ATPase. Since, any peptide with leucine has the potential to contain labeled- leucine, we therefore predicted that low abundance leucine- labeled peptides can be detected using a ‘‘targeted’’ mass spectrometry scan approach, and based on the addition of the appropriate mass to the mass of each leucine in a detected b-F1- ATPase peptide. A target list with various potential leucine- containing peptide m/z values was employed, resulting in improved efficiency in identifying stable-isotope-leucine enriched peptides.
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HPLC DAD methodology for the quantification of organic acids, furans and

HPLC DAD methodology for the quantification of organic acids, furans and

From the enological point of view, phenolic compounds mainly influence the colour, astringency, bitterness, clarity as well as the browning process [21–23]. Besides of their enological attributes, polyphenols are known to potentiate some health benefits effects due to their pharmacological activities, such as antioxidant, anti-inflammatory, anti- allergic, antiviral, anticarcinogenic, antimicrobial and vasodilatory actions [24–27]. Phenolic acids, stilbenes, flavanols and anthocyanins are the main types of poly- phenols present in wines. Some examples which are frequently reported are gallic acid, ferulic acid, quercetin, myricetin, catechin, epicatechin and trans-resveratrol [28–30]. A variety of techniques have been used for the determination of phenolic compounds in wines based on GC [31–34] and CE [35–37], but RP-HPLC has been elected and considered the most appropriate technique to analyze wine polyphenols, often used to give product composition and differentiation [38–40]. Generally, studies make use of RP C18 columns [41, 42] and binary solvent systems consisting of a solvent A, usually acidified water, and a polar organic solvent B, such as acetonitrile or methanol [43]. DAD methods are the most common [11–13, 38, 40, 41, 44–56], but other detection methods as electrochemical [57, 58] and MS [59–61] have also been used. The use of LC-MS and LC-MS/MS has become the best option for the analysis of these compounds in several matrices as well as their derived products [62–64], but the opportunity of access to these advanced technologies is still restricted for most laboratories. In Table 1, several published methods are summarized for the determination of these compounds in wine and similar matrices.
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Determination of estrogens in drinking water using HPLC-DAD.

Determination of estrogens in drinking water using HPLC-DAD.

DETERMINATION OF ESTROGENS IN DRINKING WATER USING HPLC-DAD. An analytical procedure for determination of estriol, 17β-estradiol, estrone and 17α-ethinylestradiol in drinking water is presented. The method employs solid phase extraction (SPE) and sample dechlorination as cleanup procedures, followed by HPLC-DAD analysis. Validation was carried out using RE No. 899/2003 guidelines established by the Agência Nacional de Vigilância Sanitária (National Agency of Sanitary Surveillance, Brazil), with some adaptations. The statistically evaluated results have shown that the method is selective, precise (0,06% to 19,40% CV) and accurate (91,52% to 109,41% average recoveries). The developed method was applied to the analysis of these contaminants in drinking water from São Luís, MA.
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Potential diagnostic of Branched-Chain Ketoaciduria by HPLC-DAD

Potential diagnostic of Branched-Chain Ketoaciduria by HPLC-DAD

applied to biological fluids constitute important tools for diagnosing diseases caused by errors in metabolism. Liquid chromatography has been widely and succesfully used in this context because of its high precision, reproducibility and low cost in comparison with other methods. Chromatographic techniques coupled to tandem mass spectrometry (LC-MS/MS) although displaying high resolution, sensitivity and specificity have the disadvantage of high cost, frequently unaffordable for implementation in the public health service. 10-12 On the

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 Lopes, Inês Costa

Lopes, Inês Costa

In the last few years, several samples were found to contain different combinations of multiple synthetic cannabinoids, fact which may end up in a serious health threat since these substances are not fully studied and the toxic as well as the pharmacological effects are not known. The isolation and quantification of psychoactive substances from the herbal blends , known as ‘Spice’, was performed by HPLC-UV and the identification by LC-MS/MS. The HPLC-UV method was validated for the quantification and has proven to be fit for purpose. The sample 1 has shown the coexistence of JWH-122 (29,07mg/g) and JWH-210 (175,9mg/g) while the sample 2 was found to contain one single synthetic cannabinoid, the JWH-018 (149,7mg/g). The sample 3 presented the same multiple psychoactive substances as sample 1, JWH-122 (7,3mg/g) and JWH-210 (129,9mg/g). Since these drugs are mainly smoked, a smoking machine was created* in order to characterize the chemical composition of the pyrolysis. The GC-MS analysis performed to the pyrolysis solutions has shown no degradation of the JWH-018, drug used for the assay. The toxicity impact of the characterized substances was assessed on human neuroblastoma SH-SY5Y cells, applying a combination of multiple synthetic cannabinoids (JWH-122 and JWH-210) and single one (JWH-018). The preliminary results indicate that these psychoactive substances are not toxic to the cells in the concentrations ranging from 0µM to 50µM.
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Estudo de plantas silvestres comestíveis da região mediterrânica como fontes de compostos bioativos

Estudo de plantas silvestres comestíveis da região mediterrânica como fontes de compostos bioativos

medida pelos métodos DPPH, TEAC e FRAP, é possível concluir que os compostos fenólicos parecem ser os principais responsáveis pela atividade antioxidante obtida. Da análise preliminar efetuada por HPLC-DAD os compostos fenólicos mais comuns e abundantes nos extratos analisados são os ácidos clorogénico (C. nepeta, C. arvensis e H. italicum) e rosmarínico (C. nepeta, C. arvensis, H. italicum, M. spicata e O. vulgare) e quercetina 3-O-rutinósido (B. maritima, C. nepeta, C. arvensis, B. maritima, S. hispanicus e U. dioica). No entanto, não foi possível identificar todos os compostos presentes nos extratos, como desejado, devido à falta de padrões. A falta de padrões comerciais fenólicos glicosilados é uma grande barreira na análise de compostos fenólicos por HPLC-DAD, o que torna mais difícil a sua análise e a identificação de forma correta dos compostos, uma vez que não é possível a comparação entre o espectro do composto no extrato e o padrão puro. Na maior parte das vezes só é possível identificar a família a que o composto pertence. Para uma melhor análise dos extratos será necessário, em trabalhos futuros, recorrer a uma caraterização química mais detalhada recorrendo a outras técnicas analíticas.
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