Orientadores: Helena Teixeira Godoy, Carlos Eugenio Daudt / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-07T11:15:55Z (GMT). No. of bitstreams: 1 Facco_ElizeteMariaPesamosca_D.pdf: 27687746 bytes, checksum: d51d71b95043f23c20948f904cbac415 (MD5) Previous issue date: 2006 / Doutorado / Doutor em Ciência de Alimentos

Orientador: Lauro Tatsuo Kubota / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T13:05:51Z (GMT). No. of bitstreams: 1 Luz_RitadeCassiaSilva_D.pdf: 824556 bytes, checksum: 44fa44dc39ee4ef1973fbd79f8c3e5ba (MD5) Previous issue date: 2007 / Resumo: Neste trabalho é descrito o desenvolvimento de sensores eletroquímicos à base de compostos com TCNX (tetracianoetileno e tetracianoquinodimetano) para a determinação de compostos fenólicos. Para este propósito foram preparados eletrodos de carbono vítreo modificados com tetracianoetileneto de lítio (LiTCNE) e bis(tetracianoquinodimetaneto) de bis(fenantrolina) de cobre (lI) [Cu(phen)2(TCNQ)2], ambos imobilizados em filmes de poli-l-lisina (PLL). Após esta etapa, o eletrodo modificado com LiTCNE/PLL foi testado para verificar a capacidade de eletrocatálise da reação de redução de p-nitrofenol enquanto que o eletrodo modificado com Cu(phen)2(TCNQ)2/PLL foi utilizado para a oxidação de catecol. As técnicas utilizadas para a realização deste trabalho foram a voltametria cíclica, voltametria de varredura linear, amperometria, voltametria de pulso diferencial e voltametria de onda quadrada, as quais foram utilizadas para estudar o comportamento dos eletrodos modificados, para a otimização dos parâmetros experimentais, obtenção dos parâmetros cinéticos e caracterização analítica dos sensores. Os hidrodinâmicos foram realizados com o objetivo de obter maiores informações sobre os processos de redução e oxidação de p-nitrofenol e catecol, respectivamente, sobre os eletrodos modificados. Através do gráfico de Koutech-Levich foi possível obter os valores para o coeficiente de difusão e constante de velocidade da reação (k) para os analitos em estudo. Os valores do coeficiente de difusão e de k, determinados para o p-nitrofenol, foram de 9,03 x 10 cm s e 1,65 x 10 mol L s, enquanto que para o catecol, os valores do coeficiente de difusão e de k, foram de 4,6 x 10 cm s e 1,3 x 10 mol L s, respectivamente. O aumento na velocidade de reação, tanto para o p-nitrofenol como para o catecol, foi atribuído à eficiente transferência eletrônica entre as espécies estudadas e os compostos eletroativos imobilizados nas superficies dos eletrodos de carbono vítreo. O eletrodo modificado com filme de LiTCNE/PLL apresentou uma ampla faixa de resposta linear, sensibilidade, limite de detecção e quantificação de 0,001 a 5 mmol L, 42,90 mA cm L mmol, 0,3 e 1,0 nmol L (n= 10), respectivamente, para o de p-nitrofenol, enquanto que o eletrodo modificado com Cu(phen)2(TCNQ)2/PLL apresentou uma faixa de resposta linear, sensibilidade, limite de detecção e quantificação de 0,005 a 5 mmol L (n=8), 16,10 mA cm, 1,5 e 5,0 nmol L, para o catecol. Após a aplicação destes sensores em amostras de interesse, estudos de adição e recuperação dos analitos foram realizados para avaliar a exatidão dos métodos e verificou-se que em ambos os casos foi possível uma percentagem de recuperação entre 98,87 e 104,5% para o p-nitrofenol e 99,1 e 100,1 % para o catecol / Abstract: In this work is describing the development of electrochemical sensors based on TCNX (tetracyanoquinodimethane and tetracyanoethylene) for phenolics compound determination. For this purpose glass carbon electrodes were modified with lithium tetracyanoethylenide (LiTCNE) and bis (tetracyanoquinodimethanide) of bis (phenantroline) of copper (II) [Cu(phen)2(TCNQ)2], both immobilized at films of poly-l-lysine (PLL). After this step, the modified electrode with LiTCNE/PLL was tested to verify the electrocatalysis capacity of the reduction of p-nitrofenol and the electrode modified with Cu (phen)2(TCNQ)2/PLL for the catechol oxidation. The techniques used for the accomplishment of this work were the cyclic voltametry, linear sweep voltametry, amperometry, differential pulse voltametry, and square wave voltametry, which were used to study the behavior of the modified electrodes, for the experimental parameters optimization, for the attainment of the kinetic parameters and analytical characterization of the sensors. Hydrodynamic studies were carried out with the aim to get information on the reduction processes and oxidation of p-nitrofenol and catechol, respectively, on the modified electrodes. Through the Koutech-Levich plot it was possible to obtain the values for the diffusion coefficient (Do) and kinetic constant of the reaction (k) for the analyte in study. The values of the diffusion coefficient and k, determined for p-nitrofenol, were 9,03 x 10 cm s and 1,65 10 x mol L s, whereas for catechol, the values of Do and k were 4,6 x 10 cm s e 1,3 x 10 mol L s, respectively. The increase of the reaction rate for p-nitrofenol and catechol was attributed to the efficient electron transfer between the studied species and immobilized electroactives species on superface the glassy carbon electrodes surface. The electrode modified with LiTCNE/PLL presented a wide linear response range, as well as sensitivity, detection and quantification limit of 0,001 up to 5 mmol L, 42,90 mA cm L mmol, 0,3 and 1,0 nmol L (n=10) for the p-nitrophenol, whereas the electrode modified with [Cu(phen)2(TCNQ)2], presented a linear range, sensitivity, detection and quantification limit of 0,005 a 5 mmol L (n=8), 16,10 mA cm, 1,5 e 5,0 nmol L, respectively, for catechol. After the application of these sensors in samples of interest, studies of addition and recovery of the analytes were carried out to evaluate the error of the methods and was verified that in both the cases a recovery percentages between 98,8 and 104,5% for p-nitrofenol and, 99,1 e 100,1 % for catechol / Doutorado / Quimica Analitica / Doutora em Ciências

O pequi caracteriza-se por possuir expressiva quantidade de compostos fenólicos, que por apresentarem propriedades antioxidantes estão associados com a prevenção da formação de radicais livres. Além de ser consumido in natura, é também comumente consumido na forma processada. No entanto, sabe-se que os antioxidantes presentes nos vegetais podem ser afetados pela forma de processamento e provocam alterações dos teores de fenólicos totais (FT) bem como da sua atividade antioxidante. Este trabalho objetivou avaliar o teor de FT e as propriedades antioxidantes da polpa do pequi processado e in natura. Foram obtidos os extratos alcoólicos (EALC) e aquosos (EAQ), a partir de amostras liofilizadas de diversas polpas de pequi processado (em conserva) e também do in natura, bem como as frações de ácidos fenólicos livres (AFL), ésteres solúveis de ácidos fenólicos (AFS) e ésteres insolúveis de ácidos fenólicos (AFI) de pequi processado (CB1). Os EALC e EAQ, além dos líquidos provenientes das conservas (LC), foram avaliados quanto aos teores de FT, onde se verificou que os EAQ do pequi in natura, principalmente, e do processado tiveram um maior conteúdo de FT quando comparados aos EALC. Os LC, por sua vez, apresentaram valores médios ainda maiores que os EAQ. Com relação ao teor de FT das frações, a AFL se destacou diante da AFS e AFI. Os extratos, LC e frações foram avaliados quanto à atividade antioxidante in vitro pelo sistema β-caroteno/ácido linoléico e também pelo ensaio do radical DPPH• (2,2 difenil-1-picril-hidrazila). No primeiro, verificou-se que os EAQ e LC do pequi apresentaram maior atividade que os EALC. Foi observada ainda atividade elevada em todas as frações analisadas. No segundo ensaio pelo método do radical DPPH•, pode-se observar que os extratos aquosos do pequi in natura apresentaram maior atividade, enquanto que, no pequi processado, os extratos alcoólicos e os líquidos das conservas tiveram melhores resultados. Verificou-se também que a AFL possui atividade superior às outras frações. De uma maneira geral, os resultados do pequi processado foram inferiores aos do pequi in natura tanto em relação aos teores de FT como na atividade antioxidante. Verificando-se ainda, que isto se deve principalmente à perda dos FT da polpa, indicando que houve lixiviação destes compostos para os LC. / Pequi characterized by having a significant amount of phenolic compounds, that are related with its antioxidant properties that are associated with the prevention of free radicals. Besides being eaten fresh, it is also widely consumed in processed form. However, it is known that the antioxidants present in plants can be affected by processing form and cause changes in the levels of total phenolic content (FT) and the antioxidant activity. The objective of this study was to evaluate the content of phenolic compounds and the antioxidant properties of the pequi pulp processed and fresh. Were obtained the alcoholic (EALC) and aqueous (EAQ) extracts from lyophilized samples of various pulps pequi processed (canned) and also in nature, as well as the fractions of free phenolic acids (AFL), soluble esters of phenolic acids (AFS) and insoluble esters of phenolic acids (AFI) of processed pequi (CB1). The EALC and EAq, besides the liquid from the canned (LC) were evaluated for the levels of FT, where it was found that the EAQ of the pequi in nature, mainly, and of the processed had, in general, a higher content of FT compared to EALC. The LC, in turn have showed that even greater EAQ. Regarding the content of FT of the fractions, the AFL stood in front of the AFS and AFI. The extracts, LC and fractions were also evaluated for their antioxidant activity in vitro by the system β-caroteno/ linoleic acid and by test DPPH• (2,2-diphenyl-1-picryl hydrazyl). At first, it was found that the LC and EAQ of the pequi showed greater activity than the EALC. Still high activity was observed in all fractions analyzed. In the second test, we can observe that the EAQ of the pequi in nature showed greater activity, whereas in pequi processed, the EALC and LC had better results. It was also noted that the AFL has superior activity to other fractions. In general, the results of pequi processed were lower than in fresh pequi both in relation to content of FT as antioxidant activity. Verifying also, that this is mainly due to the loss of FT of the pulp, indicating that there was leaching of these compounds to the LC.

archives@tulane.edu / 1 / Olakunle Francis Ojo

Dry bean utilization by the food industry can be increased by developing value-added processing applications. The goals of this research were to evaluate (1) the effect of milling method on the physical, chemical and functional properties of whole black bean flour and its fractions and (2) the effect of removing soluble phenolic compounds on the functional and rheological properties of black bean protein isolates. Black bean was milled with five laboratory mills [cyclone mill, hammer mill, stone mill (fine, medium, coarse), disc mill (fine, coarse), and centrifugal mill (10,000 or 12,000 rpm and 250, 500, 1000 μm aperture screen)] and the resulting flours were evaluated for their physical, chemical and flow properties of bulk samples and particle size fractions. Whole black bean flour and cotyledon flour were subjected to phenolic extraction and protein isolation, resulting in protein isolates with and without soluble phenolics. Solubility, wettability, dispersibility, water binding capacity, foam capacity and stability, emulsification capacity, and gelation properties of protein isolates were evaluated. Variation in milling method produced flours with significantly different flour characteristics. Geometric mean size of whole bean flour was negatively correlated with starch damage (r = -0.92), L* (r = -0.94), angle of repose (r = -0.94), and angle of slide (r = -0.80 to -0.90) and positively correlated with moisture (r = 0.72), and loose bulk density (r = 0.72). Milling method and particle size interaction was significant on characteristics of black bean flour fractions. Particle circularity of flour fractions had a negative correlation of r = -0.93, r = -0.81, r ≈ -0.95, and r = -0.94 with L*, angle of repose, angle of slide and compact density, respectively. Particle circularity had a positive correlation of r = 0.93 and r = 0.89 with average minimum particle size and loose bulk density, respectively. The removal of soluble phenolic compounds improved the brightness, solubility, wettability, dispersibility, foaming capacity, foaming stability, emulsion capacity, emulsion stability and gelling properties of protein isolates. These findings will help food manufacturers to process black bean ingredients using different mill settings to achieve different functionalities depending on the consumer requirements.

Red alder (Alnus rubra) is the most commercially important hardwood tree species in the Pacific Northwest and has a long history of traditional medicinal use as a source of fungicide and insecticide. Chemical analysis has shown that the diarylheptanoid oregonin ((5S)-1,7-bis(3,4-dihydroxyphenyl)-5-(β-D-xylopyranosyloxy)-heptan-3-one) is the dominant phytochemical contributing to medicinal activity. It was recently discovered that high oregonin concentration in alder leaves is associated with enhanced resistance to western tent caterpillar (Malacosoma californicum), a leaf eating lepidopteran herbivore; however, oregonin has never been directly tested on insects, or red alder-associated fungal species. In this thesis, a novel purification method was developed for the preparative extraction of oregonin from red alder leaf and bark material to directly test its biological activity. A battery of insect feeding and toxicity bioassays were carried out with several tree-defoliating caterpillars, and fungal inhibition was tested against a range of plant-associated fungal species, including several alder-associated species. This research represents the first evaluation of oregonin biological activity on insects, plant-associated fungi of the phyla Basidiomycota, and fungal-like pathogens of the phyla Oomycota. Oregonin exhibited promising insect feeding deterrent activity against generalist lepidopteran pests, including cabbage loopers (Trichoplusia ni), white-marked tussock moths (Orgyia leucostigma), and fall webworm (Hyphantria cunea) at similar concentrations shown to reduce western tent caterpillar herbivory in alder leaf bioassays. The results suggest that oregonin concentration has potential for selection as a breeding trait in managed populations of red alder to improve host resistance to leaf-eating pests. / Graduate / 2021-08-10

CHARLES UNIVERSITY PHARMACEUTICAL FACULTY IN HRADEC KRÁLOVÉ DEPARTMENT OF PHARMACEUTICAL BOTANY Title of the Diploma thesis: FENOLIC ACIDS IN PLANTS Candidate: Lucie Klížová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Diploma thesis 2020/2021, pp. 153 Phenolic acids belongs between secondary metabolites, which are part of fruits, vegetables, cereals and other plants of different families. For example, it can be plants of family Lamiaceae, Asteraceae and Ericaceae, which contain significant amounts of these substances. In plants phenolic acids play an important role and they have many human health-promoting effects including antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, anticancer activity and other. Plants containing phenolic acids are preferably also used as antidiabetics, expectorants, insecticides, hypolipidemics, cardioprotective and neurological compounds, etc. The content of these compounds in plants may be different according to monitored cultivar, the place of growth, the time of harvest and many other aspects. Presence, identification and subsequent quantification of individual phenolic acids are usually done through the HPLC and MS methods and total content of these compounds is determined through the Folin-Ciocalteu method. The diploma thesis is a literature...

Antioxidant-rich plant foods can inhibit starch and lipid digestion that are relevant to the management of type-II diabetes. Our objective was to compare the three phenolic substances (total phenolic, total flavonoids, and condensed tannin content) in crude, semi-purified extracts from eight types of foods (purified by XAD-7 column), five fractions (semi-purified extracts fractionated by Sephadex LH-20 column) from black legumes, and to compare their antioxidant capacities. The IC50 values of these crude extracts, semi-purified extracts and fractions against alpha-amylase, alpha-glucosidase and lipase were measured. Results showed that Fraction V from black soybean had the lowest IC50 value (0.25 mg/mL) against alpha-amylase; Fraction V from black bean had the lowest IC50 value (0.25 micro gram/mL) against alpha-glucosidase; Fraction IV of black bean had the lowest IC50 value (76 micro gram/mL) against lipase; myricetin showed the lowest IC50 value against alpha-amylase, alpha-glucosidase and lipase.

Yes / Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.

The aim of this research was to investigate the phytochemistry of two species Sanicula europaea and Teucrium davaeanum which are traditionally used in treatment of wounds. Four compounds were isolated from the 80% methanolic extract of S. europaea; bis-(2-ethylhexyl) phthalate (1), palmitic acid (2), rosmarinic acid (3), saniculoside N (4). Compounds 1 and 2 were isolated for the first time from this species. The structure elucidation of the isolated compounds was on the basis of 1D, 2D NMR spectroscopy and mass spectrometry measurements. Two compounds were isolated from the crude glycosides extract of T.davaeanum; 6 is a phenylethanoid glycoside and 8 is an iridoid glycoside, from the data available these may be new compounds for which the names davaeanuside A and davaeanuside B are proposed respectively." The total polyphenol content of S. europaea L, T. davaeanum leaves-flowers and T. davaeanum stem were found to be 5.0, 1.20 and 0.65 mg per 100 mg dried plant material respectively. A study of the antioxidant activity of the 50 % ethanol extracts of S. europaea and T. davaeanum showed that on a mg/mg basis S. europaea and T. davaeanum have approximately 5%, 8 % antioxidant capacity of Trolox respectively. A study of the cytotoxic activity of davaeanuside A (6), iridoid glycoside (7), davaeanuside B (8) and saponin compound (10) isolated from the crude glycosides extract of T. davaeanum revealed that saponin compound (10) inhibited the growth of Hela cells by 50 % at 50 μg/ml, P< 0.001, but the other compounds did not show activities against the tested cell lines at 100 μg/ml. The results of this work provide some basis for the traditional use of these species in the treatment of wounds. / Ministry of high education in Libya