نتایج جستجو برای: alcohols and phenols
تعداد نتایج: 16830469 فیلتر نتایج به سال:
The flavoring of vinegars with aromatic fruits and medicinal herbs is a practice with increasing trend mostly in countries with oenological tradition, resulting in a product of improved quality and consumer attractiveness. This study was directed towards the evaluation of the impact of the maceration process on the volatile signature of wine-based aromatic vinegars (WBAVs). The evaluation was p...
The main aim of this work was to produce fruit wines from pulp of gabiroba, cacao, umbu, cupuassu and jaboticaba and characterize them using gas chromatographyemass spectrometry for determination of minor compounds and gas chromatography-flame ionization detection for major compounds. Ninetynine compounds (C6 compounds, alcohols, monoterpenic alcohols, monoterpenic oxides, ethyl esters, acetate...
Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to identify the volatile organic compounds (VOCs) of the different flower development stages of Cananga odorata for the evaluation of floral volatile polymorphism as a basis to determine the best time of harvest. Electronic nose results, coupled with discriminant factor analysis, suggested that e...
Definition: The term “safety catch principle” was introduced by Kenner in 1971 for peptide chemistry to describe a strategy that allows a linker to remain stable until it is activated for cleavage by a chemical modification. Currently, the term safety-catch is applied to a linker that is cleaved by performing two different reactions instead of the normal single step, that means that the linker ...
In the present work, we have developed an efficient catalytic procedure for the chemo-selective acetylation of various substrates like amines, phenols and alcohols into their corresponding acetylated products using acetyl chloride in the presence of catalytic amount of metal acetylacetonates covalently anchored onto amine functionalized silica under solvent-free conditions. The catalysts were c...
The alkoxide-catalyzed addition of alcohols 2 to a-chloroacrylonitrile (1) at -35°C gives rise to 3-alkoxy-2-chloropropancnitriles 3; at D-5°C with excess _2 alkyl 3-alkoxy-2-chloropropanicidates 3 are obtained. The yields of 3 or 4 decrease with increasing pK, values of the alcohols 2. In the basecatalyzed addition of phenols 5 to 1, a temperature-dependent addition equilibrium is set up in wh...
Ganoderma lucidum (Lingzhi or Reishi) is known as a bitter mushroom with remarkable health benefits. The active constituents found in mushrooms include polysaccharides, dietary fibers, oligosaccharides, triterpenoids, peptides and proteins, alcohols and phenols, mineral elements (such as zinc, copper, iodine, selenium, and iron), vitamins, and amino acids. The bioactive components found in the ...
Wines from four Galician white varieties (Albariño, Loureira, Treixadura and Dona Branca) with 1992 to 1995 vintages have been analysed, in order to obtain their characterisation by the aromatic index. Monoterpenes, higher alcohols, ethyl esters, fatty acids, acetates, volatile phenols and heavy sulphur compounds were analysed by gas chromatography alone and together with mass spectrometry. Fla...
the kinetics of iodination of the phenol and substituted phenols using pyridiniumiodochloride in methanol has been studied under varying conditions. the rates show first orderkinetics each in pyridinium iodochloride and phenols. the rates of reactions are measured atdifferent temperature and activation parameters for all phenols computed. hammett plot is foundto be valid and the corrletion betw...
Aqueous extract of Inonotus obliquus was hydrolyzed in dilute hydrochloric acid. The products were extracted applying organic solvents, and separated chromatographically on a silica gel-packed column. Eluted fractions were analyzed by means of GC-MS. The presence of hydrocarbons, alcohols, phenols and various carbonyl compounds in analyzed fractions has been detected and quantified. Preliminari...
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