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Total phenols, antioxidant potential and antimicrobial activity of walnut (Juglans regia L.) green husks

Oliveira, Ivo; Sousa, A.; Ferreira, Isabel C.F.R.; Bento, Albino; Estevinho, Leticia M.; Pereira, J.A.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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The total phenols content and antioxidant and antimicrobial activities were studied in walnut (Juglans regia L.) green husks aqueous extracts of five different cultivars (Franquette, Mayette, Marbot, Mellanaise and Parisienne). Total phenols content was determined by colorimetric assay and their amount ranged from 32.61 mg/g of GAE (cv. Mellanaise) to 74.08 mg/g of GAE t (cv. Franquette). The antioxidant capacity of aqueous extracts was assessed through reducing power assay, scavenging effects on DPPH (2,2-diphenyl- 1-picrylhydrazyl) radicals and b-carotene linoleate model system. A concentration-dependent antioxidative capacity was verified in reducing power and DPPH assays, with EC50 values lower than 1 mg/ mL for all the tested extracts. The antimicrobial capacity was screened against Gram positive and Gram negative bacteria, and fungi. All the extracts inhibited the growth of Gram positive bacteria, being Staphylococcus aureus the most susceptible one with MIC of 0.1 mg/mL for all the extracts. The results obtained indicate that walnut green husks may become important in the obtainment of a noticeable source of compounds with health protective potential and antimicrobial activity.

Phenol And Para-Substituted Phenols Electrochemical Oxidation Pathways

Enache, Teodor Adrian; Oliveira-Brett, Ana Maria
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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The electrochemical behaviour of phenol, catechol, hydroquinone, resorcinol, dopamine, and para-substituted phenolic compounds, 4-ethylphenol, tyrosine, and tyramine, was studied over a wide pH range using a glassy carbon electrode. The oxidation of phenol is pH dependent and irreversible, occurring in one step, and followed by hydrolyse in ortho- and para- positions, leading to two oxidation products, catechol and hydroquinone. The oxidation of phenol oxidation products, ortho-phenol and para-phenol, is reversible and pH dependent. The oxidation potential of parasubstituted phenols varies slightly due to their substituent group in position C4, and occurs in one oxidation step corresponding to the oxidation of phenol. The oxidation products of this group of para-substituted phenols are reversibly oxidised and adsorb on the electrode surface.

Relation between antioxidant activity and electronic structure of Phenols

Lavarda, F. C.
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica Formato: 219-223
Português
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We describe a new physicochemical descriptor of the antioxidant activity of phenols, the energy difference between the two highest occupied molecular orbitals, which we believe will improve quantitative structure-activity relationship studies about these compounds. (C) 2003 Wiley Periodicals, Inc.

Remoção de fenóis por adsorção de efluente de refinaria de petróleo; Phenols removal by adsorption of effluent of petroleum refinery

Danielle Lacerda Lupetti Ferraz
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/08/2011 Português
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A crescente demanda de derivados de petróleo proporciona cada vez mais a necessidade desses produtos na sociedade atual. Este fato é reconhecido pelo desenvolvimento do país, com investimentos e desenvolvimentos em produtos energéticos e não energéticos oriundos do processamento do petróleo e, como consequência, são gerados grandes volumes de efluentes, em que os componentes fenólicos são presentes contaminantes comuns. Tratam-se de compostos tóxicos, carcinogênicos e que possuem boa solubilidade em água e baixa capacidade de biodegradação. Levando-se em conta esse aspecto, este estudo propôs mitigar os impactos ambientais utilizando o processo de adsorção em carvão ativado para remoção de fenóis. Para o desenvolvimento dessa pesquisa foi realizada uma revisão bibliográfica sobre o petróleo, algumas consequências geradas devido ao seu processamento, apresentando também técnicas de tratamento do efluente água fenólica, selecionando a adsorção como método mais eficiente e econômico para o tratamento, além do estudo experimental realizado para analisar a viabilidade técnica do tratamento, em que a caracterização do adsorvente e o conhecimento da dinâmica de adsorção são imprescindíveis para esse estudo. Os métodos de caracterização utilizados foram: análise granulométrica...

Factors influencing the production of volatile phenols by wine lactic acid bacteria

Silva, Isa; Campos, Francisco; Hogg, Tim; Couto, José António
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2011 Português
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This work aimed to evaluate the effect of certain factors on the production of volatile phenols from the metabolism of p-coumaric acid by lactic acid bacteria (LAB) (Lactobacillus plantarum, L. collinoides and Pediococcus pentosaceus). The studied factors were: pH, L-malic acid concentration, glucose and fructose concentrations and aerobic/anaerobic conditions. It was found that, in the pH range of 3.5 to 4.5, the higher the pH the greater the production of volatile phenols. This behaviour is correlated with the effect of pH on bacterial growth. Increasing levels of L-malic acid in the medium diminished the production of 4-vinylphenol (4VP) and stimulated the production of 4-ethylphenol (4EP) by L. plantarum NCFB 1752 and L. collinoides ESB 99. The conversion of 4VP into 4EP by the activity of the vinylphenol reductase may be advantageous to the cells in the presence of L-malic acid, presumably due to the generation of NAD+, a cofactor required by the malolactic enzyme. Relatively high levels of glucose (20 g/L) led to an almost exclusive production of 4VP by L. plantarum NCFB 1752, while at low concentrations (≤5 g/L), 4EP is mainly or solely produced. Part of the glucose may be diverted to the production of mannitol as an alternative pathway to regenerate NAD+. This is corroborated by the experiments done with fructose...

Solid-phase extraction and capillary electrophoresis determination of phenols from soil after alkaline CuO oxidation

LIMA, Diana L D; DUARTE, Armando C; ESTEVES, Valdemar I
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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Alkaline CuO oxidation has been used on molecular-level analyses of phenols from organic matter in the last decades. This method, originally developed by Hedges and Ertel [Hedges, J.I., Ertel, J.R., 1982. Characterization of lignin by gas capillary chromatography of cupric oxide oxidation products. Anal. Chem. 54, 174–178] has several drawbacks that have limited is wider utilization. In this paper, we propose a modification of the method using a solid-phase extraction (SPE) instead of a liquid–liquid extraction. The SPE procedure using C18 cartridges was optimized to obtain high recoveries. The sequential elution with acetonitrile and methanol was found to be the most appropriate procedure. Recoveries of the 12 phenols in individual standard solutions ranged from 84% to 113% with relative standard deviation (RSD) lower than 12%. Experiments with a mixed standard solution highlighted the competition between the different phenols for the adsorbing sites. Recoveries decreased with polarity, reaching 30% for p-hydroxybenzoic acid when present at a concentration of 2.5 · 10 3 M. A sample soil subjected to a CuO oxidation was used to test the reproducibility of the SPE method and good results were achieved, RSD ranged between 0.4% and 28.3%. The performance of the CE method was also evaluated by correlation coefficients (higher than 0.9920)...

The conversion of hydroxycinnamic acids into volatile phenols (in a synthetic media and in red wine) by Dekkera bruxellensis

Cabrita, Maria Joao; Palma, Vera; Patão, Raquel; Costa Freitas, Ana Maria
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica
Português
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The conversion of p-coumaric acid, ferulic acid, and caffeic acid into 4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in a synthetic medium and in a red wine. Liquid chromatography (HPLC-DAD) was used to quantify the phenolic acids, and gas chromatography (GC) coupled to a FID detector was used to quantify volatile phenols using a novel analytical methodology that does not require sample derivatization. Identification was achieved by gas chromatography-mass detection (GC-MS). The results show that phenolic acids concentration decreases while volatile phenols concentration increases. The proportion of caffeic acid taken up by Dekkera bruxellensis is lower than that for p-coumaric or ferulic acid; therefore less 4-ethylcatechol is formed. More important, 4-ethylcathecol synthesis by Dekkera bruxellensis in wine has never been demonstrated so far. These results contribute decisively to a better understanding of the origin of the volatile phenols in wines. The accumulation of these compounds in wine is nowadays regarded as one of the key factors of quality control.

Importance of phenols structure on their activity as antinitrosating agents: a kinetic study

Moreira, José A.; Pessêgo, Márcia; Costa, Ana M. Rosa da
Fonte: Organization of Pharmaceutical Unity with BioAllied Sciences Publicador: Organization of Pharmaceutical Unity with BioAllied Sciences
Tipo: Artigo de Revista Científica
Publicado em //2011 Português
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Objective : Nitrosative deamination of DNA bases induced by reaction with reactive nitrogen species (RNS) has been pointed out as a probable cause of mutagenesis. (Poly)phenols, present in many food items from the Mediterranean diet, are believed to possess antinitrosating properties due to their RNS scavenging ability, which seems to be related to their structure. It has been suggested that phenolic compounds will react with the above-mentioned species more rapidly than most amino compounds, thus preventing direct nitrosation of the DNA bases and their transnitrosation from endogenous N-nitroso compounds, or most likely from the transient N-nitrosocompounds formed in vivo. Materials and Methods : In order to prove that assumption, a kinetic study of the nitroso group transfer from a N-methyl-N-nitrosobenzenesulfonamide (N-methyl-N-nitroso-4-methylbenzenesulfonamide, MeNMBS) to the DNA bases bearing an amine group and to a series of phenols was carried out. In the transnitrosation of phenols, the formation of nitrosophenol was monitored by Ultraviolet (UV) / Visible spectroscopy, and in the reactions of the DNA bases, the consumption of MeNMBS was followed by high performance liquid chromatography (HPLC). Results : The results obtained point to the transnitrosation of DNA bases being negligible...

Conversion of hydroxycinnamic acids into volatile phenols in a synthetic medium and in red wine by Dekkera bruxellensis

Cabrita,Maria João; Palma,Vera; Patão,Raquel; Freitas,Ana Maria Costa
Fonte: Sociedade Brasileira de Ciência e Tecnologia de Alimentos Publicador: Sociedade Brasileira de Ciência e Tecnologia de Alimentos
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 Português
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The conversion of p-coumaric acid, ferulic acid, and caffeic acid into 4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol was studied in Dekkera bruxellensis ISA 1791 under defined conditions in a synthetic medium and in a red wine. Liquid chromatography (HPLC-DAD) was used to quantify the phenolic acids, and gas chromatography (GC) coupled to a FID detector was used to quantify volatile phenols using a novel analytical methodology that does not require sample derivatization. Identification was achieved by gas chromatography-mass detection (GC-MS). The results show that phenolic acids concentration decreases while volatile phenols concentration increases. The proportion of caffeic acid taken up by Dekkera bruxellensis is lower than that for p-coumaric or ferulic acid; therefore less 4-ethylcatechol is formed. More important, 4-ethylcathecol synthesis by Dekkera bruxellensis in wine has never been demonstrated so far. These results contribute decisively to a better understanding of the origin of the volatile phenols in wines. The accumulation of these compounds in wine is nowadays regarded as one of the key factors of quality control.

Solid state oxidation of phenols to quinones with sodium perborate on wet montmorillonite K10

Hashemi,Mohammed M.; Eftekhari-Sis,Bagher; Khalili,Behzad; Karimi-Jaberi,Zahed
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2005 Português
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Phenols were oxidized to quinones using sodium perborate (SPB) on wet montmorillonite as oxidant. The reaction was carried out at ambient temperature on the solid phase under solvent free conditions.

Copper(II) sulfate pentahydrate (CuSO4.5H2O): a green catalyst for solventless acetylation of alcohols and phenols with acetic anhydride

Heravi,Majid M.; Behbahani,Farahnaz K.; Zadsirjan,Vahideh; Oskooie,Hossien A.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2006 Português
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Alcohols and phenols were efficiently acetylated with acetic anhydride in the presence of copper (II) sulfate at room temperature in high yields.

Real-time monitoring of the heat of transfer of a homologous series of m-alkoxy phenols from isotonic aqueous solution to bacterial cells

Volpe,P. L. O.; Beezer,A. E.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 Português
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Heats of dissolution of a homologous series of m-alkoxy phenols in an osmotically stable isotonic solution and in the same media containing a suspension of Escherichia coli cells were obtained by a differential heat conduction batch calorimeter at 298 K. The calorimetric curves show an initial rapid endothermic dissolution of the solute, followed by an exothermic process. From the heats of solution, the heat of transfer (Qtrs) of these compounds from the aqueous solution to the cells was calculated. The heat of transfer is exothermic and increases with the hydrophobicity of the compounds due to the biological consequences of the interaction process with the lipidic phase.

Oxidation of mono-phenols to para-benzoquinones: a comparative study

Uliana,Marciana P.; Vieira,Ygor W.; Donatoni,Maria Carolina; Corrêa,Arlene G.; Brocksom,Ursula; Brocksom,Timothy J.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2008 Português
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The oxidation of mono-phenols to para-benzoquinones is of continuing interest due to the existence of numerous natural products containing this structural unit. The chemical reactivity of para-benzoquinones is also noteworthy, as oxidants and dienophiles in the Diels-Alder reaction. We have used for quite some time now, molecular oxygen and catalysis with [CoII(salen)] as the oxidation procedure, but felt the need for other oxidants and conditions to be of use with different phenol substrates. We now present our results on this important oxidation with a variety of oxidants, using eleven mono-phenols as substrates. The oxidants tested are cobalt, nickel, copper and vanadyl metals, with a selection of different salen type ligands. Completing this study we also investigated the use of hydrogen peroxide, OXONE®, dimethyl dioxirane and iodoxybenzoic acid.

The role of phenols from bagasse vacuum pyrolysis bio-oil in cupper sulfured ore flotation

Brossard,L. E.; Beraldo,A. L.; Cortez,L. A. B.; Brossard Jr,L. E.; Maury,E. D.; Brossard,C. O.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 Português
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Vacuum pyrolysis bagasse bio-oil collected in a series of sequential fractions was analyzed for total percentage of phenols and levoglucosan components. It was established that the ratio total phenols- to-levoglucosan could be used as an indicator of the performance of alkaline solutions of bio-oil fractions (SABO) when they are used as foaming agents to benefit flotation of sulfured cupper minerals. A high total phenol-to-levoglucosan ratio results in high percentages of Cu in cupper flotation concentrates, L Cu. A closer look at the role of individual phenols reveals that p-cresol is the main phenol, although not the only one, responsible for the observed behavior. Additionally it was noted that rather high doses of these foaming agents must be used to obtain desirable results in flotation processes. A production cost estimate allows consideration of SABO as an alternative to others commercial foaming agents, especially if an optimization study reduces doses of SABO.

The importance of hydrogen bonding in the alkylation of phenols

Alauddin, Mian Mohannad.
Fonte: Brock University Publicador: Brock University
Tipo: Electronic Thesis or Dissertation
Português
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Hydrogen bond assisted alkylation of phenols is compared with the classical base assisted reactions. The influence of solvents on the fluoride assisted reactions is discussed,· with emphasis on the localization of hydrogen bond charge density. Polar aprotic solvents such as DMF favour a-alkylation, and nonpolar aprotic solvents such as toluene favourC-alkylation of phenol. For more reactive and soluble fluorides, such as tetrabu~ylammoniumfluoride, the polar aprotic solvent favours a-alkylation and nonpolar aprotic solvent favours fluorination. Freeze-dried potassium fluoride is a better catalytic agent in hydrogen bond assisted alkylation reactions of phenol than the oven-dried fluoride. The presence of water in the alkylation reactions reduces the expected yield drastically. The tolerance of the reaction to water has also been studied. The use ofa phase transfer catalyst such as tetrabutylammonium bromide in the alkylation reactions of phenol in the presence of potassium fluoride is very effective under anhydrous conditions. Sterically hindered phenols such as 2,6-ditertiarybutyl-4-methyl phenol could not be alkylated even by using the more reactive fluorides, such as tetrabutylammonium fluoride in either polar or nonpolar aprotic solvents. Attempts were also made to alkylate phenols in the presence of triphenylphosphine oxide.

Smoke-derived taint in wine: The release of smoke-derived volatile phenols during fermentation of Merlot juice following grapevine exposure to smoke

Kennison, K.; Gibberd, M.; Pollnitz, A.; Wilkinson, K.
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica
Publicado em //2008 Português
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The release of smoke-derived volatile phenols during the fermentation of Merlot grapes, following grapevine exposure to smoke, has been investigated. The concentrations of guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, and eugenol were determined by gas chromatography−mass spectrometry and found to increase throughout the winemaking process. Only trace levels (≤1 μg/L) of guaiacol and 4-methylguaiacol could be detected in free run juice derived from the fruit of smoked vines; the highest levels, 388 μg/L and 93 μg/L, respectively, were observed in the finished wine. Control wine (derived from fruit of unsmoked vines) contained 4 μg/L guaiacol, with the volatile phenols either not detected or detected at only trace levels (≤1 μg/L) throughout fermentation. The role of enzyme and acid catalyzed hydrolysis reactions in releasing smoke-derived volatile compounds was also investigated. The volatile phenols were released from smoked free run juice by strong acid hydrolysis (pH 1.0) and enzyme (β-glucosidase) hydrolysis, but not mild acid hydrolysis (juice pH 3.2−3.7). Guaiacol was again the most abundant smoke-derived phenol, present at 431 μg/L and 325 μg/L in strong acid and enzyme hydrolysates, respectively. Only trace levels of each phenol could be detected in each control hydrolysate. This study demonstrates the potential for under-estimation of smoke taint in fruit and juice samples; the implications for the assessment of smoke taint and quantification of volatile phenols are discussed.; Kristen R. Kennison...

Glycosylation of smoke-derived volatile phenols in grapes as a consequence of grapevine exposure to bushfire smoke

Hayasaka, Y.; Baldock, G.; Parker, M.; Pardon, K.; Herderich, M.; Jeffery, D.
Fonte: Amer Chemical Soc Publicador: Amer Chemical Soc
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
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The presence of glycosides of smoke-derived volatile phenols in smoke-affected grapes and the resulting wines of Chardonnay and Cabernet Sauvignon was investigated with the aid of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). All volatile phenols studied (phenol, p-, m-, and o-cresols, methylguaiacol, syringol, and methylsyringol) could be detected as glycosylated metabolites in smoke-affected grapes in a similar fashion to that previously reported for guaiacol. These phenolic glycosides were found in smoke-affected grapes and wines at significantly elevated levels compared to those in non-smoked control grapes and wines. The extraction of these glycosides from grapes into wine was estimated to be 78% for Chardonnay and 67% for Cabernet Sauvignon. After acid hydrolysis, a large proportion of these phenolic glycosides in grapes (50%) and wine (92%) disappeared but the concentrations of volatile phenols determined by gas chromatography-mass spectrometry (GC-MS) were lower than expected. In the case of wine, the majority of the glycosides of phenol, cresols, guaiacol, and methylguaiacol were decomposed upon acid hydrolysis without releasing their respective aglycones, while syringol and methylsyringol were more effectively released.; Yoji Hayasaka...

Simultaneous determination of selected endocrine disrupters (pesticides, phenols and phthalates) in water by in-field solid-phase extraction (SPE) using the prototype PROFEXS followed by on-line SPE (PROSPEKT) and analysis by liquid chromatography-atmospheric pressure chemical ionisation-mass spectrometry

López-Roldán, P.; López de Alda, Miren; Barceló, Damià
Fonte: Springer Publicador: Springer
Tipo: Artículo Formato: 22195 bytes; application/pdf
Português
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11 pages, 4 figures, 6 tables.-- PMID: 13680063 [PubMed].-- Available online Sep 16, 2003.; In this study, a new procedure, based on on-line solid-phase extraction (SPE) and analysis by liquid-chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), has been developed for the simultaneous, multianalyte determination of 21 selected pesticides, phenols and phthalates in water. SPE was carried out on polymeric PLRP-s cartridges by percolating 20 mL-samples. For sample preconcentration, the performance of a prototype programmable field extraction system (PROFEXS) was evaluated against the commercial laboratory bench Prospekt system used for method development. The Profexs is designed for the automated on-site sampling, SPE preconcentration, and storage of up to 16 samples in SPE cartridges. These cartridges are further eluted and on-line analyzed with the Prospekt coupled to the chromatographic system. In the optimized method, where completely on-line SPE-LC-MS analysis of the samples is carried out with the Prospekt in the laboratory, detection limits lower than 100 ng/L, and satisfactory precision (relative standard deviations <25%) and accuracies (recovery percentages >75%) were obtained for most investigated compounds from the analysis of spiked Milli-Q water. The extraction efficiency achieved with the Profexs was comparable to that of the Prospekt for most compounds and somewhat lower for the most apolar analytes...

Solid phase organic synthesis: Investigation of resins and linkers for phenols

Seifert, Laurie
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
Português
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A loading and cleaving study was performed on solid phase to determine the optimal linkers and conditions for phenols, a key functional group in photographic couplers. Fourteen different commercially available resins were analyzed. Of these, ArgoGel Wang CI was determined the best for loading and cleaving the model phenol coupler. Yields of 95% for both loading and cleaving were achieved as determined by MAS Nanoprobe NMR and HPLC respectively. A few others gave great loading (90- 100%) such as Merrifield, Brominated Wang, Bromo PPOA, and TentaGel COOH, however poor cleavage ability rendered these resins insufficient for phenols.

Os florotaninos e fenóis de algas pardas (Phaeophyceae); Phlorotannins and phenols of brown algae (Phaeophyceae)

Pereira, Renato Crespo; Universidade Federal Fluminense; Yoneshigue-Valentin, Yocie; Instituto de Estudos do Mar Almirante Paulo Moreira (Marinha do Brasil); Teixeira, Valeria Laneuville; Universidade Federal Fluminense; Kelecom, Alphonse; Universidade Fe
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 01/01/1989 Português
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O floroglucinol e seus derivados, assim como outras substâncias fenólicas são abundantes em algas pardas. Apresentando estruturas bastante diversificadas, ampla atividade biológica e grande concentração em diferentes espécies, demonstram relevantes papeis fisio1ógicos e ecológicos no meio marinho, contribuindo para a maior sobrevivência das algas pardas em vias gerais. Atualmente são conhecidos lO5 metabólitos pertencentes a diferentes classes e presentes em 49 espécies de algas pardas, compreendendo o floroglucinol, 4 fucóis, 8 floretóis, 30 fuco-floretóis, 17 fu-halóis, 14 ecóis, 4 alquil-fenóis, 13 acil-fenóis, 2 halo-floroglucinol, 3 halo-floretóis, 2 halo-ecóis, 3 alcoóis benzílicos, 2 prenil-toluóis e 2 derivados sulfatados. Estes metabólitos foram classificados através de vias biossintéticas originadas no precursor floroglucinol. A ampla distribuição desses derivados fenólicos nas algas pardas sugere a sua utilização como prováveis marcadores taxonômicos e filogenéticos da classe Phaeophyceae, podendo fornecer importantes contribuições para a elucidação dos limites de separação das algas deste grupo.; Phlorotannins and their derivatives, as well as other phenolic substances are abundant in brown algae. These substances present highly diversified structures and broad biological activity spectrum. Their high concentration in a number of species demonstrates relevant physiological and ecological roles in marine environments. This fact contributes to the important survival of brown algae in these environments. Presently...