Orientador: Glaucia Maria Pastore / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-27T00:57:25Z (GMT). No. of bitstreams: 1 Brigido_BereniceMandel_M.pdf: 30516224 bytes, checksum: ec9027bfcb519c38a90217d12c0ce686 (MD5) Previous issue date: 2000 / Resumo: Muitas espécies de microrganismos produzem compostos agradáveis de aroma em meio líquido de cultura. Neste trabalho foram estudados parâmetros do processo fermentativo para a produção de compostos voláteis de aroma por novas linhagens de Neurospora sp, isoladas de beiju (massa de mandioca naturalmente fermentada), de várias regiões do Maranhão Brasil. As três linhagens deste estudo, Neurospora spl, Neurospora sp2 e Neurospora sp5 produziram aroma bastante agradável de frutas e de fungo, variando apenas sua intensidade, dependendo do meio de cultura utilizado. Os parâmetros considerados foram: composição do meio de cultura, concentração inicial de esporos, temperatura e adição de precursor. Nos ensaios para produção de compostos voláteis pelas três linhagens de Neurospora sp foram selecionados oito meios de cultura: Caldo Extrato de Malte5%, Yeast Malt Broth, Czapeck modificado, Vogel mínimo sacarose, Vogel mínimo maltose, Com Steep sem glicose ,Com Steep com glicose e Frutose/Extrato de Levedura. Foi utilizada temperatura de 30°C, com agitação de 200rpm e a formação dos compostos foi acompanhada por 144 horas de fermentação. Através da utilização da técnica de extração dos voláteis por "Purge and Trap" acoplada a cromatografia gasosa e cálculo do Índice de Retenção, foram identificados 3 classes de compostos: aldeídos ( acetaldeido), ésteres ( acetato de etila, butirato de etila e 'hexanoato de etila) e álcoois (álcool isoamílico e l-octen-3-ol). Os diferentes compostos apresentaram suas melhores concentrações produzidos por linhagens distintas, em tempos de fermentação e meios de cultura diversos. O acetaldeido teve sua melhor concentração (98ppm) produzido pela linhagem Neurospora spl em meio Frutose/Extrato de Levedura com 144horas de fermentação. Os compostos acetato de etila e butirato de etila foram produzidos nas suas concentrações máximas pela linhagem Neurospora sp2, 165ppm em meio Vogel sacarose com 72 horas de fermentação e 17,9ppm em meio Frutose/Extrato de Levedura com 96 horas de fermentação respectivamente. A linhagem Neurospora sp5 produziu as melhores concentrações de : álcool isoamílico, 213 ppm em meio Frutose/Extrato de Levedura com 96 horas de fermentação; hexanoato de etila, 2,6ppm em meio Vogel sacarose com 48 horas de fermentação e de 1-octen-3-ol, lO,3ppm em meio Yeast Malt Broth em 48 horas de fermentação. No estudo das temperaturas feito com a linhagem Neurospora spl em meio Caldo Extrato de Malte 5%, a temperatura de 25°C produziu melhores concentrações dos compostos em relação a 30°C; já no meio Yeast Malt Broth a temperatura de 30°C produziu melhores resultados. Na temperatura de 35°C não houve desenvolvimento de aroma. Os resultados revelaram que as linhagens de Neurospora sp deste estudo apresenUJm potencialidade para produção de compostos voláteis de aroma sendo importante o ajuste das condições de fermentação para melhoria da produtividade e aplicação em industrias de aromas / Abstract: Severa1microbia1 species produce a p1easantodour in liquid culture medium. It was studied some fermentative processes parameters for the production of vo1atile compounds of fiavour by new strains Neurospora sp, iso1ated from beiju (naturally fermented cassava mass), in the Brazilian State ofMaranhão. The three se1ected strains, Neurospora sp1, Neurospora sp2 and Neurospora sp5 have produced a very p1easant fruity and mushrooms 1ike aroma, whose intensity varied dependent on the culture medium used. The parameters used were: cu1ture medium composition, initia1 spores concentration, temperature and precursor' s addition. Eight cu1ture medium culture medium composition were se1ected:5% Malt Extract, Yeast Malt Broth, Czapeck, Voge1 sucrose, Voge1 maltose, Com Steep Liquor G1ucose and Frutose/Yeast Extract. The temperature chosen was 30°C with agitation of 200 rpm; the production of vo1atilecompounds was followed by 144hours of fermentation., Using Purg and Trap concentration system, coup1ed with gas chromatography and calcu1ation of retention Index, three classes of compounds cou1d be identified: a1dehyds (acetaldehyde), esters (ethy1 acetate, ethy1 butyrate and ethy1 hexanoate) and alcoho1 (isoami1icalcoho1and 1-octen-3-01). The different compounds presented their best concentrations produced by distinct strains, under different fermentation times and cu1turemediums. The "aceta1deido" had its best concentration (98 rpm) produced by Neurospora sp1's strain in Frutose /Yeast Extract medium in 144 hours of fermentation. The compounds ethy1 acetate and ethy1 butyrate were produced under their maximum concentration by Neurospora sp2's strain, 165 ppm in Voge1 Sucrose medium in 72 hours offermentation and 17,9 ppm in FrutoselYeast in 96 hours offermentation respective1y. The Neurospora sp5's strain had produced the best concentrations of: isoamilic alcoho1, 231 ppm in Frutose/Yeast Extract medium in 96 hours of fermentation; ethy1hexanoate, 2,6 ppm in Voge1 Sucrose medium in 48 hours of fermentation and 1-octen-3-01,10,3 ppm in Yeast Malt Broth medium in 48 hours of fermentation. In the temperature studied, with the Neurospora sp1's strain in 5% Malt Extract Brqth medium, under a temperature of 25°C has produced better concentrations of compounds than in 30°C; in Yeast Malt Broth medium the 30°C temperature has produced better results. Under 3SoCit wasn't found flavour development. The results have revealed that Neurospora sp's strain in this study presented potential for the production of volatile compounds of flavour, being important the adjustment of fermentation conditions to make productivity and application in flavour better / Mestrado / Mestre em Ciência de Alimentos

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-04-28T15:10:54Z No. of bitstreams: 2 Dissertação - Floyd Custódio Diniz Andrade - 2014.pdf: 4485603 bytes, checksum: c1a0728d21877b17c2606c769b2fef78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-04-30T14:29:33Z (GMT) No. of bitstreams: 2 Dissertação - Floyd Custódio Diniz Andrade - 2014.pdf: 4485603 bytes, checksum: c1a0728d21877b17c2606c769b2fef78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-04-30T14:29:33Z (GMT). No. of bitstreams: 2 Dissertação - Floyd Custódio Diniz Andrade - 2014.pdf: 4485603 bytes, checksum: c1a0728d21877b17c2606c769b2fef78 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Organylzinc chalcogenolate mediated hydrochalcogenation of propargyl alcohols organylzinc chalcogenolate (chalcogen = sulfur, selenium and tellurium) prepared from the reductive cleavage of diorganyl dichalcogenide bonds by the Zn/NH4OH system led to organylzinc chalcogenolates that provide an alternative synthetic route to produce carbon-chalcogen bonds. This work presents new synthetic methodology and discusses the general aspects and limitations of organylzinc chalcogenolate to promote the hydrochalcogenetion of 2-alkyn-1-ol derivates leading mainly the Markovnikov allylic alcohols bearing a vinylic chalcogenide substituints. We investigated the chemo, regio- and stereoselctivity for this protocol in two different systems: in aqueous medium and in organic medium. / Este trabalho descreve uma rota sintética alternativa para a produção de novas ligações carbono-calcogênio utilizando organocalocogenolatos de zinco (calcogênio = enxofre, selênio e telúrio). Estes compostos são facilmente preparados através da clivagem redutiva de dicalcogenetos de diorganoilia utilizando zinco metálico e meio básico (Nh4OH). Apresentamos uma nova metodologia para a preparação de álcoois alílicos funcionalizados através das reações de hidrocalcogenação de derivados de 1-alquin-1-ol promovida por oganocalcogenolatos de zinco, discutimos os aspectos gerais e limitações destes reagentes. Os calcognetos vinílicos produzidos apresentam a formação majoritária de adiação Markovinikov. Foram investigados a químio-, régio- e estéreosseletividade para esta metodologia em dois sistemas diferentes: em meio aquoso e em meio organico.

Submitted in fulfilment of the academic requirements of Masters in Applied Sciences (Chemistry), Durban University of Technology, 2017. / This thesis forms part of the Durban University of Technology Thermodynamics Research Unit’s project which is aimed at developing a method for determination of the liquid-liquid equilibria (LLE) data for the azeotrope {methanol + water} with an ionic-liquid (IL) using DSA5000M to assess the efficiency of the ionic liquid to be used in liquid-liquid extractions for the recovery and recycling of methanol from petroleum refinery. The objective of this study was to determine the liquid-liquid equilibria data of the azeotrope {methanol + water} using 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid with the intention to recycle methanol from the Fischer-Tropsch (FT) process by- products in petroleum industries and to utilize it in gasoline additives in a new methanol to gasoline (MTG) petroleum process. LLE studies of systems containing alcohols and water are important due to the increasing demands of oxygenated compounds to produce lead free gasoline. Light alkanols such as methanol and ethanol are reported to be suitable compounds in order to produce lead free gasoline, but the use of methanol in gasoline blends can cause phase separation problems in: 1. dry conditions, these are due to its partial solubility in saturated hydrocarbons. 2. the presence of water from ambient humidity or in storage tanks, this depend on unfavourable distribution factor between aqueous and the hydrocarbon phase. To determine the possibility of separating methanol from water using ionic liquid, the liquid-liquid equilibria data was determined at room temperature, T = 298.15 K and atmospheric pressure to investigate whether it separate from water and/or a non-phase separation if it is used as an additive. The experimental data generated was compared to that of the literature for the system {methanol (1) +toluene (2) + dodecane (3)} and showed good agreement with the literature data with only maximum deviation of ± 0.0015 in the mole fraction using density calculations and ± 0.0092 in the mole fraction when using refractive index calculations The selectivities and distribution coefficients for this system were also calculated and the maximum deviation between the two methods (nD and ρ) was ± 1.33 in selectivities and found to be ±0.001 for distribution coefficients. The maximum deviation in distribution coefficients from literature when using nD calculations for system 1 was ±0.04 and ±0.01 for ρ. For the selectivity values the deviation from that of literature of nD when compared was found to be ± 1.28 and 0.29 for ρ respectively. The selectivity values from the density calculations were found to be in the range 2.82 – 7.66 for this system with the distribution coefficient values reported in the range 0.17 – 0.23. In the second system (system 2) the generated experimental data was also compared to that of the literature for the system {water (1) + methanol (2) + cyclohexane (3)} and in good agreement with literature values with only maximum deviation of ± 0.0091 in the weight fraction based on density calculations. The selectivities and distribution coefficients were also calculated and the maximum deviation between the literature and the experimental data was computed to be at ± 0.0003 for selectivity and ±0.09 in distribution coefficient. The selectivity values were found to be in a range 0.00 - 0.04 for this system and were constant throughout the phases but significantly less than one; with the distribution coefficient values in the range 0.00 – 0.008. For 1-ethyl-3-methylimidazolium ethyl sulfate system (Ionic liquid system) the selectivity values were not constant throughout the two-phase region and the values were found to be in the range 0.63 -0.99 still below one which indicates that the ionic liquid used in this study could not be considered as a potential solvent for the separation of the investigated azeotrope. The distribution coefficients for this system were determined and found to be in the range 0.23 – 0.74. The certainty and reliability of experimentally measured tie-line data was ascertained by applying Othmer-Tobias (OT) correlations and the Non-Random, Two Liquid (NRTL) parameters. The OT correlations for system 1 was linear and indicated the certainty of the five tie-lines prepared for this system. In system 2 the OT correlation was not linear and indicated extensively high errors as well as high systematic multiplicative and additive errors in calculations of mole fractions. For the IL system the OT correlation was linear throughout the whole tie-line range and indicated the adequate precision, which denotes that the investigation was carried out with minimal random and systematic errors and indicated the efficiency of the DSA 5000 M to generate the liquid-liquid equilibria data. All the ternary systems were well correlated and in good agreement with the estimated NRTL data. It was only system 1{methanol (1) + toluene (2) + dodecane (3)} that gave a high maximum deviation ( %RSMD) of 1.288 when using the RI measurements with the minimum error margin of 0.6320, this account as to why RI measurements were not applied in other systems (system 2 and ionic liquid system). Similarly for the same system; system 1{methanol (1) + toluene (2) + dodecane (3)} when using the density measurements; the NRTL model gave a maximum deviation of 0.5620 and minimum error margin of 0.2590. The NRTL obtained for system 2 {water (1) + methanol (2) + cyclohexane (3)} gave the maximum deviation of 0.5752 and minimum error margin of 0.0127. The NRTL for the ionic liquid ternary system {[EMIM][EtSO4](1) + methanol (2) + water (3)}showed a good agreement between the experimental data and the NRTL model tie- line data with the %RSMD of 1.0201 on the upper limit and 0.1620 as a lower deviation. / M

Orientador: Luiz Carlos Dias / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-14T14:19:47Z (GMT). No. of bitstreams: 1 Vasconcelos_ValeriadeAssis_M.pdf: 7596682 bytes, checksum: 65276fd66a14ce257adec53a54afb9cc (MD5) Previous issue date: 2009 / Resumo: A preparação de álcoois homoalílicos através da adição de um reagente organometálico alílico a aldeídos é um dos processos mais importantes em síntese orgânica. O objetivo desse trabalho foi investigar o comportamento das aliltricloroestananas quirais (1, 2 e 3) em reações com metilcetonas e isatinas levando a álcoois homoalílicos contendo um centro quaternário estereogênico. As reações de acoplamentos envolvendo as aliltricloroestananas (R)-1, (S)-2 e (R)-3 (preparadas in situ a partir dos alilsilanos correspondentes) e diferentes metilcetonas levaram à formação dos álcoois homoalílicos com baixos a moderados níveis de diastereosseletividades. As reações de acoplamentos de diferentes N-alquil isatinas com as aliltricloroestananas (R)-1, (S)-2 e (R)-3 forneceram os álcoois homoalílicos com baixos a altos níveis de diastereosseletividades e bons rendimentos. Vale aqui ressaltar a dificuldade no controle da estereoquímica relativa nesse tipo de reação, pois a mesma resulta na geração de centros quaternários. / Abstract: The preparation of homoallylic alcohols through the addition of an organometallic allylic reagent to aldehydes is one of the most important processes in organic synthesis. The objective of this work was to investigate the reactions of chiral allyltrichlorostannanes (1, 2 and 3) with achiral methyl ketones and isatins leading to homoallylic alcohols containing a quaternary stereogenic center. The coupling reaction of achiral methyl ketones with chiral allyltrichlorostannanes (R)-1, (S)-2 and (R)-3 (prepared in situ from the allylsilanes) gave the corresponding homoallylic alcohols with low to moderate levels of diastereoselectivity. The coupling reaction of N-alkyl isatins with chiral allyltrichlorostannanes (R)-1, (S)-2 and (R)-3 gave the corresponding homoallylic alcohols with low to high levels of diastereoselectivity, in good yields. / Mestrado / Quimica Organica / Mestre em Química

Le trifluoroéthanol (TFE) et l'hexafluoroisopropanol (HFIP) présentent des propriétés physicochimiques particulières comme un fort pouvoir ionisant élevé, une forte capacité à donner des liaisons hydrogène, et une faible nucléophilie. Ces différentes propriétés ont été avantageusement exploitées dans plusieurs réactions sans la présence de catalyseur. Dans un premier temps, l'étude de l'amination électrophile sélective d'aromatiques avec les azodicarboxylates a été réalisée dans l'HFIP pour conduire à une famille d'hydrazines aromatiques. Ensuite l'alkylation de Friedel-Crafts avec des hétéroaromatiques et des β-nitroalcènes a conduit à des dérivées de tryptamines. Ensuite, l'halogénation sélective d'aromatiques et d'hétérocycles en présence de N-halosuccinimides (NIS, NBS et NCS) a été développée. Egalement, nous avons étudié un nouveau système combinant l'HFIP et le KHSO4 qui est un sel inorganique peu coûteux. L'association de l'HFIP et de KHSO4 (10 mol%) est un système catalytique doux et efficace pour promouvoir certaines réactions. En particulier nous avons montré que ce système catalytique a été appliqué avec succès pour l'amination directe d'aromatiques peu activés avec des azodicarboxylates pour conduire à d'autres dérivés hydrazines. Ce système a aussi montré son efficacité dans la réaction directe de benzylation de Friedel-Crafts avec des alcools benzyliques. Ainsi une grande variétés de composés diarylméthanes dissymétriques a pu être obtenue avec une excellente régiosélectivité. / Due to the electron-withdrawing character of fluoroalkyl groups, fluorinated alcohols such as trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP) exhibit a nearly unique set of properties that include high ionizing power, strong hydrogen bond donating ability, mild acidity, and low nucleophilicity. All of these properties have been exploited without the need of an external catalyst. At first, the para-selective amination of free anilines with azodicarboxylates in HFIP led to hydrazine derivatives. The Friedel-Crafts alkylation of indoles and electron-rich arenes with β-nitroalkenes succeeded to afford tryptamines derivatives. Then the regioselective halogenation of arenes and heterocycles with N-halosuccinimides (NIS, NBS, NCS) have been developed. Meanwhile, we have disclosed a new mild system between HFIP and KHSO4 which is a green, inexpensive and readily available inorganic salt. The association of HFIP/KHSO4 (10 mol%) is an efficient and mild catalytic system in order to promote some reactions. In particular, we showed that this system allowed the direct amination of slightly activated and neutral arenes with azodicarboxylates in order to give other families of hydrazines. This mild system has been applied successfully for the Friedel-Crafts benzylation with benzylic alcohols. These mild conditions provided a straightforward synthesis of a variety of unsymmetrical diarylmethanes in high yield with good to high regioselectivity

The influence of a chiral surfactant and a polymer-supported chiral additive on reduction of ketones using sodium borohydride will be described. Initial preparations involved methylation of (S)-leucinol to give (2S)-N,N-dimethyl-2-amino-4-methyl-1-pentanol (1) (67%). The chiral surfactant (2) was synthesized by reacting (1) with bromohexadecane (71%). The functionalized styrene for the polymer-supported chiral additive (5) was synthesized by reacting (1) with 4-vinylbenzyl chloride. Polymerization was carried out with 10% of the functionalized monomer (4), 5% cross-linking agent divinylbenzene, and 85% styrene with AIBN as the initiator. The activity of the chiral surfactant and polymeric additive were examined by using them as additives in a standard reduction of 2-pentanone with sodium borohydride to yield (R)- and (S)-2-pentanol (3) (20%). The resulting alcohol was analyzed by polarimetry (ee 9.5%) and also esterified with (2S)-methylbutyric acid prior to characterization by NMR. 13C NMR indicated an enantiomeric excess of 5.2% when the chiral surfactant was used, and 7% when the polymeric additive was used.

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