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1.
J Sci Food Agric ; 100(1): 81-91, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31435949

RESUMO

BACKGROUND: Coffee pulp (CP), cocoa husk (CH), and pod husk (CPH) are the main agro-residues from coffee and cocoa industries. They are sources of useful biomolecules, such as phenolic compounds, fibers, and alkaloids, among others. In this study, different compositions of deep eutectic solvents (DES) were investigated as a green and sustainable extraction media, with respect to their extraction capacity. The extraction yields were evaluated using heat stirring-assisted extraction (HSE) or ultrasound-probe assisted extraction (UPAE). RESULTS: The results showed an important effect of the DES composition. Choline chloride (ChCl) based-DES were the most effective, specifically lactic acid:ChCl (2:1 mol ratio), and the extraction capacity of DES was higher with UPAE (3 min/constant duty cycle (200 W)), in comparison with HSE (1 h/30 min). Chlorogenic acid, caffeine, and theobromine were identified as the main bioactive compounds. Interestingly, under specific conditions, DES allowed the formation of a molecule, identified as furfural by ultrahigh-performance liquid chromatography mass spectrometry (UPLC-MS), which could not be obtained using conventional extraction solvent (ethanol 70% v/v). CONCLUSION: DES showed a sustainability and high extraction capacity of biomolecules. In addition, their use as extraction solvents could lead to the formation and production of valuable building block molecules from plant biomass. © 2019 Society of Chemical Industry.


Assuntos
Cacau/química , Fracionamento Químico/métodos , Coffea/química , Extratos Vegetais/isolamento & purificação , Resíduos/análise , Cromatografia Líquida , Espectrometria de Massas , Extratos Vegetais/análise , Sementes/química , Solventes/química
2.
Br J Nutr ; 119(4): 368-380, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29498345

RESUMO

The incidence of obesity and its metabolic complications are rapidly increasing and become a major public health issue. This trend is associated with an increase in the prevalence of non-alcoholic fatty liver disease (NAFLD), insulin resistance and diabetes. The sequence of events leading to NAFLD progression and mitochondrial dysfunction and their interrelation remains to be elucidated. This study aimed to explore the installation and progression of NAFLD and its association with the liver mitochondrial structure and activity changes in rats fed an obesogenic diet up to 20 weeks. Male Wistar rats were fed either a standard or high-fat-high-fructose (HFHFR) diet and killed on 4, 8, 12, 16 and 20 weeks of diet intake. Rats fed the HFHFR diet developed mildly overweight, associated with increased adipose tissue weight, hepatic steatosis, hyperglycaemia and hyperinsulinaemia after 8 weeks of HFHFR diet. Hepatic steatosis and many biochemical modifications plateaued at 8-12 weeks of HFHFR diet with slight amelioration afterwards. Interestingly, several biochemical and physiological parameters of mitochondrial function, as well as its phospholipid composition, in particular cardiolipin content, were tightly related to hepatic steatosis installation. These results showed once again the interrelation between hepatic steatosis development and mitochondrial activity alterations without being able to say whether the mitochondrial alterations preceded or followed the installation/progression of hepatic steatosis. Because both hepatic steatosis and mitochondrial alterations occurred as early as 4 weeks of diet, future studies should consider these four 1st weeks to reveal the exact interconnection between these major consequences of obesogenic diet intake.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/etiologia , Frutose/administração & dosagem , Frutose/efeitos adversos , Mitocôndrias Hepáticas/patologia , Tecido Adiposo/crescimento & desenvolvimento , Análise de Variância , Animais , Respiração Celular , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/efeitos adversos , Intolerância à Glucose/diagnóstico , Hiperglicemia/etiologia , Hiperinsulinismo/etiologia , Lipídeos/análise , Fígado/química , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias Hepáticas/química , Mitocôndrias Hepáticas/fisiologia , Sobrepeso/etiologia , Fosfolipídeos/química , Fosfolipídeos/classificação , Fosfolipídeos/isolamento & purificação , Fosfolipídeos/metabolismo , Distribuição Aleatória , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
3.
Pharm Res ; 34(5): 1134-1146, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28224387

RESUMO

PURPOSE: Many phenolics have already been tested for their antioxidant activities using in vitro methods. However, such assays do not consider the complexity of real cellular systems, and most of the phenolics characterized with such assays shows disappointing results when evaluated in cells. Accordingly, there is a need to develop effective screening methods. METHODS: Antioxidants were first evaluated by CAT assay and then, evaluated for their ability (i) to reduce the level of ROS using fluorescent probe, (ii) to cross fibroblast cell membranes using confocal microscopy, and (iii) to target mitochondria. Antioxidants were also formulated in NADES. RESULTS: Correlation was obtained when comparing CAT results with short term inhibition (2 h) in the fibroblast cells. On the contrary, it was difficult to anticipate ROS inhibiting efficiency at long term (24 h) from both the CAT assay and the short term inhibition measurements. Indeed, some molecules displayed activity rapidly but lost it over time. In contrast, other molecules were better for long term. The comparable efficiency at long term of Bis-Ethylhexyl Hydroxydimethoxy Benzylmalonate (Bis-EHBm) and decyl rosmarinate, prompted us to further investigate the potential mitochondrial targeting of the former. Using mitochondrial probes, our results confirmed its mitochondrial location. Finally, the formulation of antioxidants in NADES could greatly improve their activity. CONCLUSIONS: Combinations of fast acting and slow acting molecules could be promising strategies to identify a performant antioxidant system. Bis-EHBm behaves as decyl rosmarinate with a confirmed mitochondrial location. Finally, the formulation of antioxidants in NADES could greatly improve their activity for ROS inhibition.


Assuntos
Fibroblastos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fenóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Química Farmacêutica/métodos , Fibroblastos/metabolismo , Humanos , Ácidos Mandélicos/farmacologia , Mitocôndrias/metabolismo , Oxirredução , Solventes/química
4.
J Nat Prod ; 79(7): 1709-18, 2016 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-27312226

RESUMO

The intense red-colored Hibiscus sabdariffa flowers are an inexpensive source of anthocyanins with potential to be used as natural, innocuous, and health-beneficial colorants. An anthocyanin-rich extract from hibiscus flowers was obtained by ultrasound-assisted extraction. By a single-step process fractionation using a Sep-Pak C18 cartridge, the main hibiscus anthocyanins, delphinidin-3-O-sambubioside (Dp-samb) and cyanidin-3-O-sambubioside (Cy-samb), were separated and then characterized via NMR and HPLC-ESIMS data. Since Dp-samb was the most abundant anthocyanin identified in the extract, its colorant properties were studied by the pH jumps method, which allowed the calculation of the single acid-base equilibrium (pK'a 2.92), the acidity (pKa 3.70), and the hydration constants (pKh 3.02). Moreover, by using size-exclusion chromatography, new cyanidin-derived anthocyanins (with three or more sugar units) were successfully identified and reported for the first time in the hibiscus extract.


Assuntos
Antocianinas/isolamento & purificação , Hibiscus/química , Antocianinas/química , Cromatografia Líquida de Alta Pressão , Flores/química , Estrutura Molecular , Dióxido de Silício
5.
Food Chem ; 429: 136854, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37531873

RESUMO

Fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (DHA), which is prone to lipid oxidation, is required by European regulation. This study aimed to identify lipid formulation parameters that improve the nutritional profile and oxidative stability of IFF. Model IFF were formulated using different lipid and emulsifier sources, including refined (POM) or unrefined red palm oil (RPOM), coconut oil (COM), dairy fat (DFOM), soy lecithin, and dairy phospholipids (DPL). After an accelerated storage, RPOM and DFOM with DPL had improved oxidative stability compared to other IFF. Specifically, they had a peroxide value twice lower than POM and 20% less loss of tocopherols for DFOM-DPL. This higher stability was mainly explained by the presence of compounds such as carotenoids in RPOM and sphingomyelin in DFOM-DPL very likely acting synergistically with tocopherols. Incorporation of dairy lipids and carotenoids into DHA-enriched IFF compositions seems promising to enhance their stability and nutritional quality.


Assuntos
Ácidos Graxos , Fórmulas Infantis , Humanos , Lactente , Ácidos Docosa-Hexaenoicos/metabolismo , Fosfolipídeos , Óleo de Palmeira , Tocoferóis , Carotenoides/metabolismo , Estresse Oxidativo
6.
Data Brief ; 51: 109649, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37869618

RESUMO

The main objective of infant follow-on formulas, consumed from the age of 6 to 12 months, is to mimic the composition of breast milk in order to meet the nutritional needs of infant. In this context, their composition is governed in Europe by a strict regulation that has evolved in 2020 to force manufacturers to improve the nutritional profile of the formulas. The objective of this dataset was to collect the ingredient lists and nutritional values of infant follow-on formulas present on the world market with a focus on the lipid fraction. The data collection was carried out from December 2020 to April 2021 directly on the product packaging or on the websites of the different brands. Only "classic" infant follow-on formulas that are widely consumed were listed. Thus, the ingredient lists and nutritional values of 91 infant formulas were collected. The nutritional values are systematically presented for 100 g of powder, for 100 Kcal and for 100 mL of formula. The sources of fats, emulsifiers and vitamins A and E were also extracted from the ingredient lists. This dataset can be used as a tool for the formulation of infant follow-on formulas or to situate the positioning of products in relation to the market.

7.
Parasit Vectors ; 14(1): 518, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620224

RESUMO

BACKGROUND: The excessive use of synthetic insecticides is responsible for many cases of resistance in insects. Therefore, the use of natural molecules of ecological interest with insecticidal properties is an alternative approach to the use of synthetic insecticides. The aim of this study is to investigating the larvicidal and adulticidal activity and the chemical composition of the essential oil of Aeollanthus pubescens on the major malaria vector, Anopheles gambiae. METHODS: Three reference strains of Anopheles gambiae sensu stricto (Kisumu, Kiskdr and Acerkis) were used in this study. The leaves of A. pubescens were collected in southern Benin. The standard World Health Organisation (WHO) guidelines for larvicide evaluation were used, and the chemical composition of the essential oil was analysed by gas chromatography coupled to mass spectrometry. Adult mosquitoes of each strain were exposed to pieces of net coated with the essential oil for 3 min using the WHO cone bioassay method. Probit regression analysis was used to determine the concentrations that would kill 50 and 95% of each test population (LC50, LC95) and the knockdown time for 50 and 95% of each test population (KDT50, and KDT95). The difference between the mortality-dose regressions for the different strains was analysed using the likelihood ratio test (LRT). The log-rank test was performed to evaluate the difference in survival between the strains. RESULTS: A total of 14 components were identified, accounting for 98.3% of total oil content. The major components were carvacrol (51.1%), thymyle acetate (14.0%) and É£-terpinene (10.6%). The essential oil showed larvicidal properties on the Kisumu, Acerkis and Kiskdr strains, with LC50 of 29.6, 22.9 and 28.4 ppm, respectively. With pieces of netting treated at 165 µg/cm2, the KDT50 of both Acerkis (1.71 s; Z = 3.34, P < 0.001) and Kiskdr (2.67 s; Z = 3.49, P < 0.001) individuals were significantly lower than that of Kisumu (3.8 s). The lifespan of the three mosquito strains decreased to 1 day for Kisumu (χ2 = 99, df = 1, P < 0.001), 2 days for Acerkis (χ2 = 117, df = 1, P < 0.001) and 3 days for Kiskdr (χ2 = 96.9, df = 1, P < 0.001). CONCLUSION: Our findings show that A. pubescens essential oil has larvicide and adulticide properties against the malaria vector An. gambiae sensu stricto, suggesting that this essential oil may be a potential candidate for the control of the resistant malaria-transmitting vectors.


Assuntos
Anopheles/efeitos dos fármacos , Inseticidas/farmacologia , Lamiaceae/química , Mosquitos Vetores/efeitos dos fármacos , Óleos Voláteis/análise , Óleos Voláteis/farmacologia , Folhas de Planta/química , Animais , Anopheles/classificação , Bioensaio , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Lamiaceae/classificação , Larva/efeitos dos fármacos , Controle de Mosquitos/métodos , Óleos Voláteis/química
8.
Metabolites ; 11(2)2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33671946

RESUMO

Rice bran (RB) corresponds to the outer layers of whole grain rice and contains several phenolic compounds (PCs) that make it an interesting functional food ingredient. PC richness is enhanced in pigmented RB varieties and requires effective ways of extraction of these compounds. Therefore, we investigated conventional and deep eutectic solvents (DES) extraction methods to recover a wide array of PCs from red and black RB. The RB were extracted with ethanol/water (60:40, v/v) and two DES (choline chloride/1.2-propanediol/water, 1:1:1 and choline chloride/lactic acid, 1:10, mole ratios), based on Generally Recognized as Safe (GRAS) components. Besides the quantification of the most typical phenolic acids of cereals, nontargeted metabolomic approaches were applied to PCs profiling in the extracts. Globally, metabolomics revealed 89 PCs belonging to flavonoids (52%), phenolic acids (33%), other polyphenols (8%), lignans (6%) and stilbenes (1%) classes. All extracts, whatever the solvents, were highly concentrated in the main phenolic acids found in cereals (37-66 mg/100 g in black RB extracts vs. 6-20 mg/100 g in red RB extracts). However, the PC profile was highly dependent on the extraction solvent and specific PCs were extracted using the acidic DES. The PC-enriched DES extracts demonstrated interesting DPPH scavenging activity, which makes them candidates for novel antioxidant formulations.

9.
J Agric Food Chem ; 68(35): 9308-9318, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32786829

RESUMO

Novel hydroxyalkyl esters and bis-aryl esters were synthesized from sinapic and caffeic acids and aliphatic α,ω-diols of increasing chain lengths from 2 to 12 carbon atoms. Then, their antiradical reactivity (DPPH assay) and their antioxidant activity in a model oil-in-water emulsion (CAT assay) were evaluated. All the esters showed lower antiradical activities compared to their corresponding phenolic acid. This decrease was associated with the steric hindrance in hydroxyalkyl esters, and intramolecular interactions in bis-aryl esters. Regarding the two bis-aryl esters series in emulsion, the antioxidant capacity was improved with alkyl chain lengthening up to four carbons, after which it decreased for longer chains. This "cutoff" effect was not observed for both hydroxyalkyl esters series for which the alkyl chain lengthening results in a decrease of the antioxidant activity.


Assuntos
Antioxidantes/síntese química , Ácidos Cafeicos/química , Ácidos Cumáricos/química , Ésteres/química , Antioxidantes/química , Estrutura Molecular
10.
Food Chem ; 309: 125586, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31670124

RESUMO

Oil-in-water (O/W) emulsions are important delivery systems of omega-3 fatty acids (n-3 FA). We investigated the effect of sinapic acid esters concentration and chain length, the electrical charge of the emulsifier and emulsion pH on the oxidative stability of n-3 FA rich O/W emulsions. Echium oil was applied as n-3 FA source. A 24 factorial design was used to simultaneously evaluate these factors. Peroxide value, malondialdehyde, 2,4-heptadienal and 2,4-decadienal were measured in the emulsions. pH and the electrical charge of the emulsifier modulated the antioxidant effectiveness of sinapic acid esters, while concentration was not relevant. The combination of positively charged emulsifier with neutral pH provided the best oxidative stability for echium oil emulsions. Our results also suggested that the increase of length chain of sinapic acid, from C4 to C12, reduced the secondary products of oxidation, when echium oil emulsions were prepared using negatively charged emulsifier under acidic conditions.


Assuntos
Ácidos Cumáricos/química , Ácidos Graxos Ômega-3/química , Antioxidantes/química , Antioxidantes/farmacologia , Ácidos Cumáricos/farmacologia , Echium/química , Emulsões , Ésteres , Oxirredução , Óleos de Plantas/química
11.
J Agric Food Chem ; 68(35): 9568-9575, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32786852

RESUMO

A strange cutoff phenomenon of a series of protocatechuic acid alkyl esters had been noticed using the conjugated autoxidizable triene (CAT) assay. Two parabolic shapes of antioxidant activities of protocatechuic acid alkyl esters described as ″the double cutoff effect″ have been speculated as a result of an oxidative driving force generated in the aqueous phase. The aim of this research was to investigate the double cutoff effect using various types of oxidation driving forces in different CAT-based assays. To further explain the phenomenon, the natural oxidation of conjugated autoxidizable triene (NatCAT) assay has been developed for the first time by relying solely on only the lipid autoxidation of tung oil-in-water (O/W) emulsions. In conclusion, NatCAT exhibited different antioxidant and oxidation patterns from both CAT and apolar radical-initiated CAT assays, and only one cutoff point was obtained. This discovery would lead to a greater understanding of the complexity of antioxidant/lipid oxidation dynamics in O/W emulsion systems.


Assuntos
Antioxidantes/química , Ésteres/química , Hidroxibenzoatos/química , Emulsões/química , Oxirredução , Óleos de Plantas/química
12.
J Nutr Biochem ; 64: 182-197, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30530258

RESUMO

Metabolic syndrome components, including obesity, dyslipidemia and impaired glucose homeostasis, become a major public health issue. Muscles play a predominant role in insulin-mediated glucose uptake, and high fat diets may negatively affect muscle function and homeostasis. This work aimed to study the time-course of muscle lipid accumulation, oxidative stress and mitochondrial dysfunction and their association to impaired glucose homeostasis in rats fed an obesogenic diet. Male Wistar rats were fed with a standard or a high fat/high fructose (HFHFr) diet and sacrificed on 4, 8, 12, 16, 20 weeks. Rats fed the HFHFr diet developed mild overweight, increased liver and adipose tissue weights and glucose intolerance. The impaired glucose homeostasis increased gradually with the HFHFr diet to become significant on the 12th and 16th weeks of diet. In parallel, the muscle lipid composition showed an increase in the saturated fatty acids and the monounsaturated fatty acids with a marked decrease in the polyunsaturated fatty acids. The HFHFr diet also increased muscle contents of both diacylglycerols and Ceramides. Surprisingly, HFHFr diet did not induce major muscle mitochondrial dysfunction or oxidative stress. These results indicate that muscle lipid alterations, as well as impaired glucose homeostasis occur as early as the 8th week of HFHFr diet, increase to reach a plateau around the 12th-16th weeks of diet, and then attenuate towards the end of study. At these diet treatment durations, muscle mitochondrial activity and oxidative stress remained unchanged and do not seem to have a major role in the observed impaired glucose homeostasis.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Frutose/efeitos adversos , Glucose/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Animais , Ceramidas/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Frutose/metabolismo , Homeostase , Masculino , Mitocôndrias Musculares/efeitos dos fármacos , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfolipídeos/química , Fosfolipídeos/metabolismo , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
13.
Anal Biochem ; 380(2): 282-90, 2008 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-18585362

RESUMO

Described here is a novel spectrophotometric method for estimating antioxidant capacity in a 96-well microplate using as UV probes the conjugated triene triacylglycerols (TAGs) naturally present in tung oil. The TAGs of this commercially available oil contain around 86% eleostearic acid, an octadecatrienoic acid with conjugated trienes exhibiting strong UV absorption at 273 nm. In an oil-in-water emulsion at 37 degrees C, the azo initiator 2,2'-azobis(2-amidinopropane) dihydrochloride generated a constant flux of peroxy radicals, which destroyed the conjugated trienes. The absorbance decay at 273 nm, related to oxidative degradation of conjugated triene TAGs, was monitored in the absence and presence of various concentrations of antioxidants. To validate this new method, the antioxidant capacity of four phenolic compounds (gallic acid, (-)-epicatechin, chlorogenic acid, and rosmarinic acid) was measured using an area-under-the-curve calculation and expressed as Trolox equivalents, the value for Trolox being taken as reference. The order of efficacy was found to be rosmarinic acid > chlorogenic acid approximately epicatechin>Trolox>gallic acid, which can be partially explained by the number of catecholic moieties and the polarity of these antioxidants. Moreover, the conjugated autoxidizable triene (CAT) assay provided good insight into antioxidant behavior (i.e., retarder or chain breaker). The same molecules were then analyzed in 2,2-diphenyl-1-picrylhydrazyl and fluorescein-based oxygen radical absorbance capacity assays, and the results are discussed critically with respect to those obtained with the CAT assay. This new method may constitute an easy-to-use, sensitive, and high-throughput in vitro protocol for evaluation of the antioxidant capacity of pure molecules and natural extracts in lipid oxidation.


Assuntos
Antioxidantes/química , Óleos de Plantas/química , Espectrofotometria Ultravioleta/métodos , Triglicerídeos/química , Catequina/química , Ácido Clorogênico/química , Cromanos/química , Cromatografia Líquida de Alta Pressão/métodos , Cinamatos/química , Depsídeos/química , Ácido Gálico/química , Cinética , Peroxidação de Lipídeos/efeitos dos fármacos , Microquímica/métodos , Reprodutibilidade dos Testes , Ácido Rosmarínico
14.
J Agric Food Chem ; 65(39): 8683-8690, 2017 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-28880083

RESUMO

The aim of this work was to evaluate the potential of crude lipase powders made from Adansonia grandidieri and Jatropha mahafalensis seeds for the synthesis of fatty acid alkyl esters in a solvent-free system. The influence of the nature of the alcohol, the amount of glycerol, and hydration of the powder was investigated. Results showed that the activity of these crude lipase powders was inversely proportional to the alcohol polarity and the amount of the glycerol in the reaction medium. To ensure optimum activity, A. grandidieri and J. mahafalensis powders must be conditioned to a water activity of 0.33 and 0.66. To obtain a fatty acid ethyl ester yield greater than 95% with A. grandidieri, ethanol should be introduced at an amount corresponding to a triacylglycerol to ethanol molar ratio of 2:1 every 15 h for 96 h and use 25% of preconditioned crude lipase powders (2 additions of 12.5%).


Assuntos
Biocombustíveis , Lipase/metabolismo , Sementes/enzimologia , Adansonia/enzimologia , Catálise , Esterificação , Ésteres , Etanol , Ácidos Graxos , Glicerol , Jatropha/enzimologia , Termodinâmica , Água
15.
Food Chem ; 230: 189-194, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28407900

RESUMO

Hibiscus sabdariffa flowers represent an interesting source of anthocyanins, one of the most important plant pigments, which are responsible of the intense red color of the calyces, and have potential as natural colorants for food applications. Nevertheless, anthocyanins are highly hydrosoluble and unstable compounds. On this basis, the aim of this work was to increase the lipophilicity of the hibiscus anthocyanins by lipophilization, in order to obtain amphiphilic colorants, which could be easily incorporated in lipid-rich food matrices. Octanoyl derivatives of delphinidin-3-O-sambubioside and cyanidin-3-O-sambubioside were chemically obtained for the first time, and characterized by means of HPLC-ESI-MS data.


Assuntos
Antocianinas/uso terapêutico , Dissacarídeos/química , Flores/química , Hibiscus/química , Espectrometria de Massas/métodos , Extratos Vegetais/química , Antocianinas/análise , Antocianinas/química
16.
Int J Biol Macromol ; 105(Pt 2): 1440-1445, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28751049

RESUMO

The blue-green microalga, Arthrospira sp., isolated from the sea of Kssour Essef in Mahdia (Tunisia), was purified and then identified both morphologically and genetically based on 16S rRNA gene sequence. Following physicochemical analysis, the prokaryotic microalga tested represented a competitive source of pigments and showed a considerable rate in protein (64%) which was confirmed by FTIR measurement. The lipid content (4%) was quantified by the gravimetric method and the intracellular lipid bodies were detected with the Nile red staining. Using gas chromatography coupled with flame ionization detector, the fatty acid profile revealed the presence of 27.4% and 32.88% of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), respectively. Given the richness of the isolated microalga in unsaturated fatty acids, we have developed a SYBR Green real time PCR method for the specific identification of Arthrospira sp. Δ9 desaturase gene. This current method will be of great value for carrying out high-throughput studies like cloning, heterologous expression and structure-function relationship analysis.


Assuntos
Cianobactérias/genética , Estearoil-CoA Dessaturase/genética , Cianobactérias/enzimologia , Cianobactérias/metabolismo , Ácidos Graxos/metabolismo , RNA Ribossômico 16S/genética
17.
Chem Phys Lipids ; 209: 19-28, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29061286

RESUMO

Regardless of the applications: therapeutic vehicle or membrane model to mimic complex biological systems; it is of a great importance to develop simplified, reproducible and rapid model assays allowing for a relevant assessment of the liposomal membrane oxidation and therefore antioxidant activity of selected molecules. Here, we describe a new and high-throughput assay that we called "Vesicle Conjugated Autoxidizable Triene (VesiCAT)". It is based on specific UV absorbance spectral properties of a new phospholipid probe, synthesized with natural conjugated eleostearic acid extracted from Tung oil. The VesiCAT assay has been developed with two different radical generators (2,2'-azobis(2-amidinopropane) dihydrochloride; AAPH and 2,2'-azobis(2,4-dimethylvaleronitrile); AMVN), producing a constant flux of oxidant species, either in membrane or in aqueous phase. This method appears very efficient in assessing the effect of various pure antioxidant molecules in their ability to preserve liposomes from oxidative degradation. In addition, the AAPH- and AMVN-induced oxidations offer the possibility of extracting different but complementary information with respect to the antioxidants efficacy.


Assuntos
Antioxidantes/química , Ácidos Linolênicos/química , Lipossomos/química , Sondas Moleculares/química , Fosfolipídeos/química , Ensaios de Triagem em Larga Escala , Oxirredução , Fosfolipídeos/síntese química , Óleos de Plantas/química
18.
J Agric Food Chem ; 54(7): 2726-31, 2006 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-16569067

RESUMO

The enzymatic properties of Plumeria rubra latex have been evaluated for the first time, showing a high activity in both hydrolysis and synthesis reactions, and compared to the biocatalytic behavior of babaco (Vasconcellea x Heilbornii cv.) latex. Both biocatalysts have been optimized by studying the various parameters that influence reaction kinetics. The optimum temperatures for hydrolysis reactions were 50 and 55 degrees C for babaco and Plumeria, respectively. The optimum pH for babaco latex was 7, whereas for Plumeria latex, two optimal pH values (4 and 7) were observed. With regard to esterification and acyl transfer reactions such as alcoholysis and interesterification, the influence of thermodynamic water activity on reaction yields was determined and correlated with water sorption and desorption isotherms. When babaco latex is used as a biocatalyst, optimal synthesis reaction yields are obtained when the enzymatic extract is stabilized at a water activity value of 0.38, which corresponds to a water content of 5.7%. This optimal level of hydration is located on the linear portion of the biocatalyst's sorption isotherm, where the water molecules exhibit high-energy interactions with the protein network. In synthesis reactions (esterification, alcoholysis, and interesterification) biocatalyzed by Plumeria latex, correlation between best reaction yields and water activity cannot be done. Indeed, the sorption isotherm plot has an atypical shape, indicating that water might be trapped in the latex matrix and, consequently, that the water content of the biocatalyst is highly dependent on the hydration history of the latex.


Assuntos
Apocynaceae/enzimologia , Lipase/metabolismo , Magnoliopsida/enzimologia , Extratos Vegetais/metabolismo , Acilação , Esterificação , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Lipídeos/análise , Óleos de Plantas/metabolismo , Óleo de Girassol , Temperatura , Termodinâmica
19.
J Agric Food Chem ; 64(46): 8838-8847, 2016 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-27797524

RESUMO

The aim of this work was to investigate lipase activities in crude extracts from Adansonia suarezensis, Adansonia grandidieri, Moringa drouhardii, Moringa oleifera, Jatropha mahafalensis, and Jatropha curcas seeds in ethanolysis and hydrolysis reactions. All crude extracts from germinated seeds showed both ethanolysis and hydrolysis activities. The influence of germination, the delipidation procedure, and the triacylglycerol/ethanol molar ratio on their ethanolysis activity was studied. Crude extracts of Jatropha and Adansonia seeds showed optimal activity at pH 8 with an optimum temperature of 30 and 40 °C, respectively. The study of the regioselectivity of crude extracts from J. mahafalensis and A. grandidieri seeds, which had the most active hydrolysis reaction, showed 1,3 regioselectivity in the hydrolysis reaction of vegetable oils. The crude extract from A. grandidieri seeds showed no typoselectivity, whereas the typoselectivity of the crude extract of J. mahafalensis seeds depended on the type of reaction.


Assuntos
Biocombustíveis/análise , Lipase/química , Óleos de Plantas/química , Proteínas de Plantas/química , Plantas/enzimologia , Biocatálise , Plantas/química , Estereoisomerismo , Especificidade por Substrato
20.
Food Chem ; 194: 749-57, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26471615

RESUMO

Hibiscus sabdariffa L. is a worldwide consumed plant, principally after infusion of its dried sepals and calyces, which are usually discarded. Nevertheless, they represent a potential source of natural bioactive compounds, e.g. polyphenols, which could add value to this under-exploited plant. Protocatechuic acid (PA) was chosen as a model of the phenolic acids that can be extracted from H. sabdariffa. In order to modify PA hydrophilic character, which limits its use in lipid-rich food products, PA was esterified to C1-C18 alcohols, and the impact of lipophilization on its antioxidant activity was evaluated in both, an homogeneous (DPPH and ORAC methods) and an heterogeneous (CAT method) system. Results herein obtained showed that, depending on the grafted alkyl chain length, lipophilization could positively affect the antioxidant activity of PA in heterogeneous media; therefore, support its use as an innovative way to synthesize molecules with an improved antioxidant capacity and potential to be used as multifunctional preservatives in food.


Assuntos
Flores/química , Hibiscus/química , Hidroxibenzoatos/química , Antioxidantes/química , Extratos Vegetais/química
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