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1.
Mar Drugs ; 21(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36976243

RESUMO

An undescribed hybrid phenalenone dimer, talaropinophilone (3), an unreported azaphilone, 7-epi-pinazaphilone B (4), an unreported phthalide dimer, talaropinophilide (6), and an undescribed 9R,15S-dihydroxy-ergosta-4,6,8 (14)-tetraen-3-one (7) were isolated together with the previously reported bacillisporins A (1) and B (2), an azaphilone derivative, Sch 1385568 (5), 1-deoxyrubralactone (8), acetylquestinol (9), piniterpenoid D (10) and 3,5-dihydroxy-4-methylphthalaldehydic acid (11) from the ethyl acetate extract of the culture of a marine sponge-derived fungus, Talaromyces pinophilus KUFA 1767. The structures of the undescribed compounds were elucidated by 1D and 2D NMR as well as high-resolution mass spectral analyses. The absolute configuration of C-9' of 1 and 2 was revised to be 9'S using the coupling constant value between C-8' and C-9' and was confirmed by ROESY correlations in the case of 2. The absolute configurations of the stereogenic carbons in 7 and 8 were established by X-ray crystallographic analysis. Compounds 1,2, 4-8, 10 and 11 were tested for antibacterial activity against four reference strains, viz. two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), as well as three multidrug-resistant strains, viz. an extended-spectrum ß-lactamase (ESBL)-producing E. coli, a methicillin-resistant S. aureus (MRSA) and a vancomycin-resistant E. faecalis (VRE). However, only 1 and 2 exhibited significant antibacterial activity against both S. aureus ATCC 29213 and MRSA. Moreover, 1 and 2 also significantly inhibited biofilm formation in S. aureus ATCC 29213 at both MIC and 2xMIC concentrations.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Poríferos , Talaromyces , Animais , Staphylococcus aureus , Escherichia coli , Poríferos/química , Talaromyces/química , Antibacterianos/química , Esteroides , Testes de Sensibilidade Microbiana
2.
Sensors (Basel) ; 22(24)2022 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-36560020

RESUMO

The geographical traceability of extra virgin olive oils (EVOO) is of paramount importance for oil chain actors and consumers. Oils produced in two adjacent Portuguese regions, Côa (36 oils) and Douro (31 oils), were evaluated and fulfilled the European legal thresholds for EVOO categorization. Compared to the Douro region, oils from Côa had higher total phenol contents (505 versus 279 mg GAE/kg) and greater oxidative stabilities (17.5 versus 10.6 h). The majority of Côa oils were fruity-green, bitter, and pungent oils. Conversely, Douro oils exhibited a more intense fruity-ripe and sweet sensation. Accordingly, different volatiles were detected, belonging to eight chemical families, from which aldehydes were the most abundant. Additionally, all oils were evaluated using a lab-made electronic nose, with metal oxide semiconductor sensors. The electrical fingerprints, together with principal component analysis, enabled the unsupervised recognition of the oils' geographical origin, and their successful supervised linear discrimination (sensitivity of 98.5% and specificity of 98.4%; internal validation). The E-nose also quantified the contents of the two main volatile chemical classes (alcohols and aldehydes) and of the total volatiles content, for the studied olive oils split by geographical origin, using multivariate linear regression models (0.981 ≤ R2 ≤ 0.998 and 0.40 ≤ RMSE ≤ 2.79 mg/kg oil; internal validation). The E-nose-MOS was shown to be a fast, green, non-invasive and cost-effective tool for authenticating the geographical origin of the studied olive oils and to estimate the contents of the most abundant chemical classes of volatiles.


Assuntos
Nariz Eletrônico , Paladar , Humanos , Azeite de Oliva/química , Portugal , Aldeídos
3.
Mar Drugs ; 20(11)2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36354995

RESUMO

An unreported isocoumarin, (3S,4R)-4-hydroxy-6-methoxymellein (2), an undescribed propylpyridinium anthraquinone (4), and an unreported C-glucosyl resorcinol derivative, acetyl carnemycin E (5c), were isolated, together with eight previously reported metabolites including p-hydroxybenzaldehyde (1), 1,3-dimethoxy-8-hydroxy-6-methylanthraquinone (3a), 1,3-dimethoxy-2,8-dihydroxy-6-methylanthraquinone (3b), emodin (3c), 5[(3E,5E)-nona-3,5-dien-1-yl]benzene (5a), carnemycin E (5b), tajixanthone hydrate (6a) and 15-acetyl tajixanthone hydrate (6b), from the ethyl acetate extract of the culture of a marine sponge-derived fungus, Aspergillus stellatus KUFA 2017. The structures of the undescribed compounds were elucidated by 1D and 2D NMR and high resolution mass spectral analyses. In the case of 2, the absolute configurations of the stereogenic carbons were determined by comparison of their calculated and experimental electronic circular dichroism (ECD) spectra. The absolute configurations of the stereogenic carbons in 6a and 6b were also determined, for the first time, by X-ray crystallographic analysis. Compounds 2, 3a, 3b, 4, 5a, 5b, 5c, 6a, and 6b were assayed for antibacterial activity against four reference strains, viz. two Gram-positive (Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212) and two Gram-negative (Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853), as well as three multidrug-resistant strains. However, only 5a exhibited significant antibacterial activity against both reference and multidrug-resistant strains. Compound 5a also showed antibiofilm activity against both reference strains of Gram-positive bacteria.


Assuntos
Isocumarinas , Poríferos , Animais , Isocumarinas/farmacologia , Isocumarinas/química , Poríferos/química , Fungos/química , Antraquinonas/farmacologia , Antraquinonas/química , Antibacterianos/química , Resorcinóis , Testes de Sensibilidade Microbiana
4.
Food Chem ; 395: 133570, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-35777205

RESUMO

At olive oil industrial extraction, water addition is a practice overcoming the formation of thick pastes. The effect of water addition (0 to 6.2%, kgadded water/kgolives), during the industrial milling of cv. Arbequina olives, on the oils' chemical-sensory quality, was evaluated. Despite the extra virgin olive oil classification, compared with the water incorporation (1.2-6.2%), extraction without water addition resulted into oils that showed less primary oxidation (lower peroxide values and K232), greater total phenolic content (+12-22%) and higher oxidative stability (+22-31%). No water addition increased the oils secoiridoids content (+5-13%), mainly oleacein (+27-79%). Oils extracted without water addition had a more intense ripe fruity sensation (≥ +11%) but lower fruit intensities (at least -4%). Thus, the quality and stability of the cv. Arbequina oils can be favoured if extracted without adding water during the olives industrial milling.


Assuntos
Olea , Óleos de Plantas , Frutas/química , Azeite de Oliva/análise , Oxirredução
5.
Food Chem ; 393: 133327, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35653996

RESUMO

Leaves incorporation during the extraction of olive oils can enhance their chemical-sensory quality. Thus, leaves from cvs. Arbequina or Santulhana were added (1%, w/w) during the extraction of Arbequina oils using an Abencor system, being discussed the impacts on the phenolics and volatiles formation enzymatic pathways. Leaves addition contributed to a significant decrease (P-value < 0.05) of the contents of secoiridoids (-11%), C6-aldehydes (-16%), and ester compounds (-22%). This could be tentatively related to a reduction of the enzymatic activity of secoiridoids biosynthesis and lipoxygenase pathways, promoted by the leaves' addition. Moreover, in the presence of leaves, the oils' total contents of phenolics and volatiles were significantly reduced (-7 and -17%, respectively). Contrary, the incorporation of leaves significantly increased (P-value < 0.05) the contents of C6-alcohols (+37%) and the intensities of the green fruity (+25%) and apple (+30%) sensations.


Assuntos
Olea , Compostos Orgânicos Voláteis , Iridoides , Olea/metabolismo , Azeite de Oliva/análise , Fenóis/análise , Folhas de Planta/química , Óleos de Plantas , Compostos Orgânicos Voláteis/metabolismo
6.
Mar Drugs ; 19(8)2021 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-34436296

RESUMO

Previously unreported anthraquinone, acetylpenipurdin A (4), biphenyl ether, neospinosic acid (6), dibenzodioxepinone, and spinolactone (7) were isolated, together with (R)-6-hydroxymellein (1), penipurdin A (2), acetylquestinol (3), tenellic acid C (5), and vermixocin A (8) from the culture of a marine sponge-associated fungus Neosartorya spinosa KUFA1047. The structures of the previously unreported compounds were established based on an extensive analysis of 1D and 2D NMR spectra as well as HRMS data. The absolute configurations of the stereogenic centers of 5 and 7 were established unambiguously by comparing their calculated and experimental electronic circular dichroism (ECD) spectra. Compounds 2 and 5-8 were tested for their in vitro acetylcholinesterase and tyrosinase inhibitory activities as well as their antibacterial activity against Gram-positive and Gram-negative reference, and multidrug-resistant strains isolated from the environment. The tested compounds were also evaluated for their capacity to inhibit biofilm formation in the reference strains.


Assuntos
Antraquinonas/farmacologia , Antibacterianos/farmacologia , Fungos/química , Éteres Fenílicos/farmacologia , Poríferos/microbiologia , Acetilcolinesterase/efeitos dos fármacos , Animais , Organismos Aquáticos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Fitoterapia
7.
Molecules ; 26(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34443658

RESUMO

In recent decades, fungi-derived naturally occurring quinazolines have emerged as potential drug candidates. Nevertheless, most studies are conducted for bioactivity assays, and little is known about their absorption, distribution, metabolism, and elimination (ADME) properties. To perform metabolic studies, the synthesis of the naturally occurring quinazolinone, fiscalin B (1), and its chloro derivative, 4-((1H-indol-3-yl)methyl)-8,10-dichloro-1-isobutyl-1,2-dihydro-6H-pyrazino[2,1-b]quinazoline-3,6(4H)-dione (2), disclosed as an antibacterial agent, was performed in a gram scale using a microwave-assisted polycondensation reaction with 22% and 17% yields, respectively. The structure of the non-natural (+)-fiscalin B was established, for the first time, by X-ray crystallography as (1R,4S)-1, and the absolute configuration of the naturally occurring fiscalin B (-)-1 was confirmed by comparison of its calculated and experimental electronic circular dichroism (ECD) spectra as (1S,4R)-1. in vitro metabolic studies were monitored for this class of natural products for the first time by ultra-high-performance liquid chromatography (UHPLC) coupled with high-resolution mass spectrometry (HRMS). The metabolic characteristics of 1 and 2 in human liver microsomes indicated hydration and hydroxylation mass changes introduced to the parent drugs.


Assuntos
Antibacterianos/metabolismo , Produtos Biológicos/metabolismo , Metaboloma/genética , Pirazinas/metabolismo , Antibacterianos/síntese química , Antibacterianos/química , Produtos Biológicos/síntese química , Produtos Biológicos/química , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Cristalografia por Raios X , Fungos/efeitos dos fármacos , Humanos , Indóis/síntese química , Indóis/química , Indóis/metabolismo , Espectrometria de Massas , Estrutura Molecular , Pirazinas/síntese química , Pirazinas/química , Quinazolinas/síntese química , Quinazolinas/química , Quinazolinas/metabolismo , Estereoisomerismo
8.
Talanta ; 226: 122122, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676677

RESUMO

An electronic nose, comprising nine metal oxide sensors, has been built aiming to classify olive oils according to the fruity intensity commercial grade (ripely fruity or light, medium and intense greenly fruity), following the European regulated complementary terminology. The lab-made sensor device was capable to differentiate standard aqueous solutions (acetic acid, cis-3-hexenyl, cis-3-hexen-1-ol, hexanal, 1-hexenol and nonanal) that mimicked positive sensations (e.g., fatty, floral, fruit, grass, green and green leaves attributes) and negative attributes (e.g., sour and vinegary defects), as well as to semi-quantitatively classify them according to the concentration ranges (0.05-2.25 mg/kg). For that, unsupervised (principal component analysis) and supervised (linear discriminant analysis: sensitivity of 92% for leave-one-out cross validation) classification multivariate models were established based on nine or six gas sensors, respectively. It was also showed that the built E-nose allowed differentiating/discriminating (sensitivity of 81% for leave-one-out cross validation) extra virgin olive oils according to the perceived intensity of fruitiness as ripely fruity, light, medium or intense greenly fruity. In conclusion, the gas sensor device could be used as a practical preliminary non-destructive tool for guaranteeing the correctness of olive oil fruitiness intensity labelling.

9.
Phytochemistry ; 185: 112709, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33636575

RESUMO

Four undescribed prenylated phenylbutyrolactones, aspulvinones R, S, T and U, were isolated together with the previously reported aspulvinones A, B', H and 4-hydroxy-3,5-bis(3-methylbut-2-en-1-yl)benzaldehyde, from cultures of the marine sponge-derived fungus Aspergillus flavipes KUFA1152. The structures of the undescribed compounds were established on the basis of extensive analysis of 1D and 2D NMR and HRMS spectra. In the case of aspulvinone T, the absolute configuration of its stereogenic carbon was established by comparison of the experimental and calculated electronic circular dichroism (ECD) spectra. The structure of the previously reported compounds were elucidated by 1D and 2D NMR analysis as well as comparison of their 1H or/and 13C NMR data with those reported in the literature. Aspulvinones B', H, R, S, T and a mixture of aspulvinones A and U exhibited antibacterial activity against reference strains and multidrug-resistant isolates from the environment as well as capacity to inhibit biofilm formation in the reference strains. However, none of the tested compounds showed potential synergy with clinically relevant antibiotics on multidrug-resistant isolates.


Assuntos
Poríferos , Animais , Antibacterianos/farmacologia , Aspergillus , Fungos , Estrutura Molecular
10.
Microbiol Res ; 245: 126693, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33482404

RESUMO

A wide array of fungal endophytes is known to inhabit plant tissues and were recently recognized as essential for plant health. A better description of the scarcely known endophyte microbiota in olive tree phyllosphere is the first step for elucidating the microbial interactions that lead to olive disease establishment. In this work, the fungal endophytic community of the phyllosphere of different olive tree cultivars (Cobrançosa, Galega vulgar, Madural, Picual, Verdeal Transmontana) is revealed by using a metabarcoding strategy targeting ITS1 barcode. A total of 460 OTUs were obtained, increasing the broad view of fungal endophytes inhabiting the olive tree phyllosphere, in particular yeast endophytes. New endophytes were persistently found in all cultivar tissues. Different olive tree cultivars depicted distinct endophyte communities. Olive cultivars exhibited dissimilar amounts of fungi with distinct ecological functions, which could explain at least in part their differential susceptibility/tolerance to olive diseases.


Assuntos
Endófitos/classificação , Endófitos/genética , Fungos/classificação , Fungos/fisiologia , Micobioma , Olea/microbiologia , Código de Barras de DNA Taxonômico , Endófitos/isolamento & purificação , Fungos/isolamento & purificação
11.
Phytochemistry ; 181: 112575, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33166747

RESUMO

Two undescribed viomellein derivatives, xanthoelegansin and spiroxanthoelegansin, were isolated together with clavatol, sitosteanone, vioxanthin, xanthomegnin, viomellein, rubrosulphin, rubrosulphin diacetate, viopurpurin , ochratoxin A, ochratoxin A methyl ester, ochratoxin B and ochratoxin ß, from cultures of the marine sponge-associated fungus Aspergillus elegans KUFA0015. The structures of the undescribed compounds were established based on an extensive analysis of 1D and 2D NMR spectra as well as HRMS data. The structure of xanthoelegansin and the absolute configuration of its stereogenic carbons were confirmed by X-ray analysis. The change in conformation of xanthoelegansin was interpreted using quantum mechanical theoretical calculation data in combination with the observation of the change of the proton signals of the 1,3-dioxepine ring in 1HNMR spectra at varying temperatures. The mechanisms of the formation of xanthoelegansin and spiroxanthoelegansin from viomellein were proposed. Clavatol, sitosteanone, vioxanthin, xanthomegnin, viomellein, xanthoelegansin, rubrosulphin, rubrosulphin diacetate, ochratoxin A, ochratoxin A methyl ester, ochratoxin B and ochratoxin ß were assayed for their antibacterial activity against reference strains and multidrug-resistant isolates from the environment. The tested compounds were also evaluated for their capacity to inhibit biofilm formation in the reference strains.


Assuntos
Antibacterianos , Poríferos , Animais , Antibacterianos/farmacologia , Aspergillus , Benzopiranos , Indóis , Naftoquinonas , Nitrocompostos
12.
Food Chem ; 337: 127726, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795854

RESUMO

Phenolic compounds contribute to the bioactive properties of olive oil. However, olive oils can only support a health claim concerning the protection against oxidative stress depending on the polyphenolic concentration, requiring effective measures during extraction to preserve/enhance their concentrations. The effect of the malaxation temperature (22, 28 and 34 °C) on the phenolic profile was studied for industrially extracted cv. Cobrançosa oils. Higher malaxation temperatures decreased the contents of the majority of the chromatographically detected compounds (P < 0.05, one-way ANOVA), enabling oils' differentiation. This decreasing trend was observed for hydroxytyrosol and tyrosol bound forms, determinant for the health claim, which were also negatively affected by temperature, despite revealing that all the industrially extracted oils tested supported the health claim. The observed constant free to bound forms ratio showed that the temperature range tested had a minor effect on bound-forms hydrolysis, being both free and bound forms equally affected by temperature.


Assuntos
Saúde , Azeite de Oliva/química , Fenóis/análise , Temperatura , Fenômenos Mecânicos , Fenóis/química
13.
Phytochemistry ; 174: 112336, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32192964

RESUMO

Targeting the transmissible stages of the Plasmodium parasite that develop in the human and mosquito host is a crucial strategy for malaria control and elimination. Medicinal plants offer a prolific source for the discovery of new antimalarial compounds. The recent identification of the gametocytocidal activity of lophirone E, obtained from the African plant Lophira lanceolata (Ochnaceae), inspired the evaluation of the plant also against early sporogonic stages of the parasite development. The bioassay-guided phytochemical study led to the isolation of two known lanceolins and of a new glycosylated bichalcone, named glucolophirone C. Its stereostructure, including absolute configuration of the bichalcone moiety, was elucidated by means of NMR, HRMS, ECD and computational calculations. Lanceolin B proved to be a potent inhibitor of the development of Plasmodium early sporogonic stages indicating that the plant produces two different stage-specific antimalarial agents acting on transmissible stages in the human and mosquito host.


Assuntos
Antimaláricos , Malária , Ochnaceae , Animais , Humanos , Casca de Planta , Extratos Vegetais , Plasmodium falciparum
14.
Mar Drugs ; 17(6)2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31242631

RESUMO

Previously unreported meroterpene, acremine S (1), and benzopyran derivative, acremine T (2), were isolated, together with lumichrome (3), ergosterol (4) and ergosterol 5,8-endoperoxide, from cultures of the marine sponge-associated fungus Acremonium persicinum KUF1007. The structure of the previously unreported compounds was established based on an extensive analysis of 1D and 2D NMR spectra as well as HRMS data. The absolute configurations of the stereogenic centers of 1 were established, unambiguously, based on NOESY correlations and comparison of calculated and experimental electronic circular dichroism (ECD) spectra. Compounds 1-3 were tested for their in vitro acetylcholinesterase and butyrylcholinesterase inhibitory activities.


Assuntos
Acremonium/química , Benzofuranos/química , Inibidores da Colinesterase/química , Poríferos/microbiologia , Terpenos/química , Animais , Dicroísmo Circular/métodos , Ergosterol/química , Flavinas/química , Espectroscopia de Ressonância Magnética/métodos , Testes de Sensibilidade Microbiana/métodos
15.
Food Sci Technol Int ; 25(6): 472-479, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30813781

RESUMO

Edible flowers, such as pansies, have a short shelf-life. Crystallization is a treatment used to prolong the shelf-life of fruits and vegetables. So, the aim of the present work was to investigate the effect of crystallization in the physicochemical, microbial and antioxidant properties of pansies (Viola×wittrockiana) during room temperature storage (7, 15, 30, 60 and 90 days). Comparing fresh and crystallized pansies, significant differences were detected. After 90 days of storage, crystallized pansies kept similar appearance to those immediately after treatment. A significant decrease in water activity, moisture, ash and protein contents was observed between 0 and 90 days of storage for crystallized pansies. Some bioactive compounds, such as flavonoids and monomeric anthocyanins, showed a significant decrease after 90 days of storage, while hydrolysable tannins increased. Concerning phenolic compounds, these maintained constant along storage. The microbial load of crystallized pansies during all storage time was lower than fresh ones. So, crystallization can be an effective method for pansies preservation, being some nutritional and bioactive compounds, little affected during storage. However, crystallization contributed to a high increase in sugar content and energy values compared to fresh pansies.


Assuntos
Flores/química , Flores/microbiologia , Microbiologia de Alimentos , Armazenamento de Alimentos , Viola , Clara de Ovo , Sacarose , Fatores de Tempo
16.
J Food Sci ; 84(3): 490-498, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30779144

RESUMO

Edible flowers consumption and use are an increasing food trend worldwide, although information concerning their nutritional composition and nutraceutical value is still scarce. Thus, the aim of this study was to contribute to the popularization of pansies (Viola × wittrockiana), through the analysis of the nutritional and nutraceutical features of pansies with different colors (white, yellow, and red) and flowering stages. Both flower type and flowering stage influenced the flower composition. When completely open, white and yellow pansies had the highest contents of protein (>2.00 g/100 g fresh weight), while red pansies had the highest content of carbohydrates (8.0 g/100 g fresh weight). Regarding the fatty acid profiles, linoleic acid was always predominant (ranging between 18.7 and 51.0 g/100 g fatty acids), followed by the palmitic and linolenic acids. During flowering, there was an increase in protein, fat, and linolenic acid contents in white and yellow pansies, whereas in red pansies the values did not change. Red pansies were characterized by the highest contents of total carotenoids (873 to 1300 µg ß-carotene/g dry weight) and monomeric anthocyanins (303 to 402 µg Cy-3 glu/g dry weight); however, white and yellow pansies showed an increase in the values of total reducing capacity (total phenols), hydrolysable tannins, flavonoids, monomeric anthocyanins, and antioxidant activity from the bud to completely open flower stage. Our results underline the nutritional differences between pansies with different colors at distinct stages of development and their potential health benefits, suggesting that they can be used as ingredient to improve the nutritional properties of foods. PRACTICAL APPLICATION: The market of edible flowers is increasing, although little information in nutritional view is available. So, the present study was conducted to contribute to the popularization of edible flowers as a new and prospective source for the food industry, as well as a promising product for human nutrition. The results of the present study underline the nutritional differences between pansies with different colors at distinct stages of development and their potential health benefits, suggesting that they can be used as ingredient to improve the nutritional properties of foods.


Assuntos
Antioxidantes/análise , Dieta , Flores/química , Nutrientes/análise , Valor Nutritivo , Polifenóis/análise , Viola/química , Antocianinas/análise , Antioxidantes/farmacologia , Carotenoides/análise , Flavonoides/análise , Humanos , Fenóis/análise , Plantas Comestíveis , Estudos Prospectivos
17.
Talanta ; 197: 363-373, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771949

RESUMO

Olive oil is highly appreciated due to its nutritional and organoleptic characteristics. However, a huge compositional variation is observed between olive oils, requiring the use of diverse analytical techniques for its classification including titration, spectrophotometry and chromatography, as well as sensory analysis. Chemical analysis is usually time-consuming, expensive and require skilled technicians, while the sensorial ones are dependent upon individual subjective evaluations, even if performed by trained panellists. This work evaluated and demonstrated the feasibility of using a potentiometric electronic tongue, comprising non-specific lipid polymeric and cross-sensitive sensor membranes, coupled with chemometric tools based on different sub-sets of sensors (from 11 to 14 sensors), to predict key quality parameters of olive oils based on single-run assays. The multivariate linear models established for 23 centenarian olive trees from different cultivars allowed predicting peroxide value, oxidative stability, total phenols and tocopherols contents, CIELAB scale parameters (L*, a* and b* values), as well as 11 gustatory-retronasal positive attributes (green, sweet, bitter, pungent, tomato and tomato leaves, apple, banana, cabbage, fresh herbs and dry fruits) with satisfactory accuracy (0.90 ±â€¯0.07 ≤ R2 ≤ 0.98 ±â€¯0.02 for the repeated K-fold-CV procedure, which ensured that 25% of the data was used for internal-validation purposes). The electronic tongue device had an accuracy statistically similar to that achieved with standard analytical techniques, pointing out the versatility of the device for the fast and simultaneous chemical and sensory analysis of olive oil.


Assuntos
Nariz Eletrônico , Azeite de Oliva/análise , Azeite de Oliva/química , Físico-Química , Potenciometria
18.
Molecules ; 24(1)2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30626056

RESUMO

A new polyketide erubescensoic acid (1), and the previously reported xanthonopyrone, SPF-3059-26 (2), were isolated from the uninvestigated fractions of the ethyl acetate crude extract of the marine sponge-associated fungus Penicillium erubescens KUFA0220. The structures of the new compound, erubescensoic acid (1), and the previously reported SPF-3059-26 (2), were elucidated by extensive analysis of 1D and 2D-NMR spectra as well as HRMS. The absolute configuration of the stereogenic carbon of erubescensoic acid (1) was determined by X-ray analysis. Erubescensoic acid (1) and SPF-3059-26 (2), together with erubescenschromone B (3), penialidin D (4), and 7-hydroxy-6-methoxy-4-oxo-3-[(1E)-3-oxobut-1-en-1-yl]-4H-chromen-5-carboxylic acid (5), recently isolated from this fungus, were assayed for their antibacterial activity against gram-positive and gram-negative reference strains and the multidrug-resistant (MDR) strains from the environment. The capacity of these compounds to interfere with the bacterial biofilm formation and their potential synergism with clinically relevant antibiotics for the MDR strains were also investigated.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Penicillium/química , Policetídeos/química , Policetídeos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Estrutura Molecular
20.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1100-1101: 158-164, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30336346

RESUMO

The enantioresolution of pentedrone and methylone was carried out at a multi-milligram scale by liquid chromatography on a Chiralpak AS® stationary phase. The excellent enantioresolution using this column allowed to collect highly pure enantiomeric fractions, achieving enantiomeric ratios higher than 98%. An overall recovery of 72% was achieved for pentedrone enantiomers and 80% for methylone. Furthermore, the absolute configuration of the enantiomers of both cathinones was determined for the first time by electronic circular dichroism (ECD) spectroscopy, with the aid of theoretical calculations, as (+)­(S) and (-)­(R)-pentedrone, and (-)­(S) and (+)­(R)­methylone.


Assuntos
Metanfetamina/análogos & derivados , Metilaminas/análise , Metilaminas/química , Pentanonas/análise , Pentanonas/química , Cromatografia Líquida de Alta Pressão , Dicroísmo Circular , Metanfetamina/análise , Metanfetamina/química , Modelos Moleculares , Estereoisomerismo
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