266 resultados para Fries,
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A study has been undertaken of the published literature on the Fries rearrangement, thermal, photo and microwave, since its discovery in 1908. A resume of these publications and especially of those pertaining to the thia-Fries rearrangement of sulfamate esters, has been compiled. Phenyl sulfamate, phenyl N,N-dimethylsulfamate, phenyl N,N-diethylsulfamate and phenyl N,N-di-n-propylsulfamate and many of their substituted compounds have been synthesised and purified, a total of thirty nine esters. The sulfamates have been characterised by mp / bp, infrared, C, H and N microanalysis and mass spectrum. Many of these sulfamates, twenty six in total, have been rearranged to sulfonamides in the thia-Fries rearrangement, and subsequently purified. The products were characterised by mp / bp, infrared, C, H and N microanalysis and mass spectrum. Mechanistic studies of the sulfamates have been investigated, particularly phenyl N,N-dimethylsulfamate. The rearrangement with various catalysts and catalytic ratios, the effect of solvents on the rearrangement and many crossover experiments have been carried out to determine the molecularity i.e. whether it is an inter-, intra- or bimolecular reaction. The microwave induced thia-Fries rearrangement has been examined to determine what effect this irradiation has on the rearrangement. Photo thia-Fries rearrangement has also been investigated.
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The sesquiterpene (+)-allo-aromadendrane-10b-14-diol 1 was the lead compound to the preparation of several derivatives in order to test their biological activity against A. salina, C. sphaerospermum, E. coli and S. aureus. In this way the monoalcohols (+)-viridiflorol 4, 9 and 11 were synthesized from 1 together with the acetal 6, the ketal 7, and the ketone 8. The oxirane 3 and nitrile 5 were also prepared using as an intermediate the tosylate derivative 2.
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The phytochemical investigation of Rollinia leptopetala led to the isolation of a new compound named α-terpinyl caffeate, and five known compounds, being three sesquiterpenes, spathulenol, β-caryophyllene and 4β,10α-aromadendrane-diol, and two alkaloids, (-)-3-hydroxynornuciferine and (+)-norisocorydine. These alkaloids are being described for the first time in this genus. The structures of the compounds were determined by analysis of IR, MS and NMR data, as well as by comparison with literature data. The crude extract of R. leptopetala leaves demonstrated a weak cytotoxicity on sarcoma 180 cells with an IC50 of 512.3 µg/mL. However, the in vivo results showed that the extract exhibited a significant dose-dependent tumor growth reduction.
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Von Wrightin taitelijaveljeksistä Wilhelm v. Wright (1810-1887) muutti Ruotsiin 18-vuotiaana avustaakseen vanhempaa veljeään Magnusta SKANDINAVIENS FÅGLAR -teoksen (ks. kohde 258) valmistamisessa. Wilhelm jäi pysyvästi Ruotsiin ja ryhtyi työskentelemään Kuninkaallisen tiedeakatemian piirtäjänä. Vuonna 1836 alkoi ilmestyä laaja kalakuvasto SKANDINAVIENS FISKAR, johon hän oli laatinut kuvat ja eläintieteilijät C. U. Ekström, B. F. Fries ja C. J. Sundevall kirjoittaneet tekstit. Tästä teoksesta tuli v. Wrightin kuvitustöistä merkittävin ja korkeatasoisin. Myöhemmin v. Wright toimi Bohuslänin kalastuksentarkastajan virassa, mutta halvaantui loppuelämäkseen yli kolmenkymmenen vuoden ajaksi.
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Bound in: Reise durch Schweden, Schwedisch-Lapland, Finland und Dänemark / von Matthaus Consett. Leipzig : In der C. Weigel-Schneiderʼschen Kunst- und Buchhandlung von Nürnberg, 1790.
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Com o objetivo de obter uma equação que, através de parâmetros lineares dimensionais das folhas, permitisse estimar a área foliar de Wissadula subpeltata (Kuntze) Fries, estudaram- se correlações entre a área foliar real e o comprimento da folha ao longo da nervura principal (C ), largura máxi ma da folha (L) , comprimento do espaço entre o ponto de inserção do pecíolo na folha até a primeira ramificação da nervura principal (CE), L + C, L x C e L x CE. Todas as equações, geométricas ou lineares simples, permitiram boas estimativas da área foliar . Do pont o de vista prático, sugere- se optar pela equação linear simples envolvendo o produto C x L, considerando o coeficiente linear igual a zero. Deste modo, a estimativa da área foliar de W. subpeltata pode ser feita pel a fórmula Y = 0, 85 49 (C x L), ou seja 85 ,49% do produto entre o comprimento da nervura principal e a largura máxima da folha.
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A survey of the gasteroid mycota from "cerrado" vegetation of the state of São Paulo, Brazil, revealed for the first time a rare species of nidulariaceous fungi, Nidularia pulvinata, growing on decaying wood of Syagrus flexuosa (Mart.) Beccari (Palmae). Descriptions of the macro and microscopic features of N. pulvinata, including taxonomic considerations, are given.
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Tesis (Maestría en Ciencias con Especialidad en Microbiología) UANL
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Tesis (Maestría en Ciencias con Especialidad en Microbiología) UANL
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Tesis (Doctor en Ciencias con Especialidad en Microbiología) U.A.N.L.
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BACKGROUND: Since the discovery in 2002 of acrylamide in a wide range of foods, there has been much work done to explore mechanisms of formation and to reduce acrylamide in commercial products. This study aimed to investigate simple measures which could be used to reduce acrylamide formation in home-cooked French fries, using potatoes from three cultivars stored under controlled conditions and sampled at three time points. RESULTS: The reducing sugar content for all three cultivars increased during storage, which led to increased acrylamide levels in the French fries. Washing and soaking (30 min or 2 h) raw French fries before cooking led to reductions in acrylamide of up to 23, 38 and 48% respectively. Pre-treated fries were lighter in colour after cooking than the corresponding controls. CONCLUSION: Pre-treatments such as soaking or washing raw French fries in water reduce acrylamide and colour formation in the final product when cooking is stopped at a texture-determined endpoint. (c) 2008 Society of Chemical Industry.