- Lipase-mediated selective acetylation of primary alcohols in ethyl acetate
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An environmental friendly process to selectively acetylate primary alcohols was demonstrated. The esterification process consists of treatment of a primary alcohol in the presence of immobilized C. antarctica lipase (Novozyme-435) in ethyl acetate at room temperature. Primary alcohols were acetylated in the presence of secondary alcohols and phenols.
- de Souza, Ernane C.,Romero-Ortega, Moises,Olivo, Horacio F.
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supporting information
p. 287 - 290
(2017/12/29)
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- Expanding ester biosynthesis in Escherichia coli
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To expand the capabilities of whole-cell biocatalysis, we have engineered Escherichia coli to produce various esters. The alcohol O-acyltransferase (ATF) class of enzyme uses acyl-CoA units for ester formation. The release of free CoA upon esterification with an alcohol provides the free energy to facilitate ester formation. The diversity of CoA molecules found in nature in combination with various alcohol biosynthetic pathways allows for the biosynthesis of a multitude of esters. Small to medium volatile esters have extensive applications in the flavor, fragrance, cosmetic, solvent, paint and coating industries. The present work enables the production of these compounds by designing several ester pathways in E. coli. The engineered pathways generated acetate esters of ethyl, propyl, isobutyl, 2-methyl-1-butyl, 3-methyl-1-butyl and 2-phenylethyl alcohols. In particular, we achieved high-level production of isobutyl acetate from glucose (17.2 g l -1). This strategy was expanded to realize pathways for tetradecyl acetate and several isobutyrate esters.
- Rodriguez, Gabriel M,Tashiro, Yohei,Atsumi, Shota
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p. 259 - 265
(2014/04/03)
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- Aggregate formation in the intercalation of long-chain fatty acid esters into liposomes
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Various hydrophobic benzenediacetic esters, the corresponding benzenedipropionic esters, and branched alkyl esters were intercalated into DMPC liposomes, where the molar ratio (n/n) of ester:DMPC was 1:5. In the case of the very long-chain derivatives, double carbonyl peaks were observed in the 13C NMR spectrum. This doubling phenomenon was observed only for the carbonyl peaks, whose chemical shift is most sensitive to solvent polarity, and disappeared when the ester:DMPC molar ratio drops below 1:15. This doubling reflects the presence of two populations in these samples: one group includes those molecules which are intercalated within the liposome and feel the polarity corresponding to the liposomal microenvironment; the other consists of aggregates of these long-chain derivatives located in the extra-liposomal aqueous phase.
- Cohen, Yael,Afri, Michal,Frimer, Aryeh A.
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scheme or table
p. 120 - 125
(2009/12/31)
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- Enantioselective monoterpene alcohol acetylation in Origanum, Mentha and Salvia species
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Selected plants within the Origanum, Mentha and Salvia genera, that contain significant amounts of chiral volatile alcohols and their related acetates, exhibit remarkable enantioselectivity of alcohol acetyl transferase (AAT) activity and particularly can discriminate between linalool enantiomers. Origanum dayi AAT produced almost enantiomerically pure (R)-linalyl acetate by enzymatic acetylation of racemic linalool, whereas the closely related O. majorana AAT produced a mixture of (R)- and (S)-linalyl acetate with a ratio of 6:4. Vmax of O. dayi acetylation activity was 30-fold higher for (R)-linalool, whereas in O. majorana no such differences were found.
- Larkov, Olga,Zaks, Alon,Bar, Einat,Lewinsohn, Efraim,Dudai, Nativ,Mayer, Alfred M.,Ravid, Uzi
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experimental part
p. 2565 - 2571
(2009/04/06)
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- Compositions related to a novel endophytic fungi and methods of use
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This invention provides pesticidally effective compositions related to a novel endophytic fungi named Muscodor. Specifically, the invention relates to commercially useful formulations of Muscodor and methods for preparing such formulations. It also provides various synthetic pesticidal mixtures of volatile organic compounds isolatable from Muscodor grown on various substrates. Also provided are methods for inhibiting the growth of organisms, such as microbes, insects, and nematodes by exposing such organisms or the habitats thereof to the above Muscodor-related compositions.
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- Preparation process of aminoacetamide derivative
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Disclosed herein are novel processes for preparing aminoacetamide derivatives, wherein: (1) a secondary amine is reacted with a 2-haloacetamide in the presence or absence of at least one solvent selected from water, lower alcohols, aromatic solvents and acetic acid esters; (2) an N-benzylideneamine derivative is reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is then reacted with a 2-haloacetamide; and (3) a primary amine is reacted with benzaldehyde to form an N-benzylideneamine derivative, this product is then reacted with dimethyl sulfate or diethyl sulfate to form a secondary amine, and this secondary amine is further reacted with a 2-haloacetamide. The 2-aminoacetamide derivatives are useful as intermediates for the preparation of novel antibiotics.
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- Facile Acylation of Aclohols Using Esters and Silica Gel-supported Metallic Sulphates and Hydrogen Sulphates
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Alcohols are acylated in a quite simple operation in high yields by being heated in esters in the presence of silica gel-supported metallic sulphates and hydrogen sulphates, such as Ce(SO4)2, Ti(SO4)2, Fe2(SO4)3, and NaHSO4.
- Nishiguchi, Takeshi,Taya, Hisachi
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p. 172 - 173
(2007/10/02)
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- Acid-induced 13C Nuclear Magnetic Resonance Chemical Shift Changes of Ether and Ester Carbon Atoms
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13C N.m.r. chemical shifts of ehters dissolved in tetrachloromethane are displaced on addition of trifluoroacetic acid.The displacements result from independent interactions of the acid with the substrate oxygen atoms and alkyl residues.The structure-dependent and stereoselective shift changes are useful for signal assignments, structure determination, conformational analysis, assessment of the distribution of rapidly interconverting conformers of esters, and estimation of the relative basicity of ethers.
- Begtrup, Mikael
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p. 1609 - 1618
(2007/10/02)
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- Classical Carbonium Ions. Part 13. Rearrangements from Secondary to Primary Alkyl Groups during Reactions involving Carbonium Ions
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The rearrangement of cyclohexylamine to cyclopentylmethyl derivatives, earlier reported in brief, is confirmed.A similar reaction with 4-trans-t-butylcyclohexylamine is shown to give trans-3-t-butylcyclopentylmethyl derivatives, defining the conformational requirements and stereochemical course of the rearrangement.In similar reactions 2-butylamine and 3-pentylamine give, in small yield, derivatives of primary alcohols.Cyclohexyl toluenesulphonate probably gives a very small yield of cyclopentylmethyl acetate.All these reactions involve the formation of products formally derived from carbonium ions much less stable than those initially generated, and yields, though small, are much larger than can be accounted for by classical descriptions.It is proposed that corner-protonated cyclopropanes ('non-classical carbonium ions') are 'intermediates' of very short lifetime in these reactions; the extent to which it is possible to regard species of very short lifetime as intermediates is discussed.
- Cooper, Catherine N.,Jenner, Peter J.,Perry, Nigel B.,Russel-King, Jonquil,Storesund, Hans J.,Whiting, Mark C.
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p. 605 - 612
(2007/10/02)
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