Search results for "ACETONE"

Novel acrylamido monomers with higher hydrophilicity and improved hydrolytic stability: I. Synthetic route and product characterization.

1996

The novel acrylamido monomer reported by our group (N-acryloylaminoethoxyethanol, AAEE; Chiari et al., Electrophoresis 1994, 15, 177-186), found to combine high hydrophilicity with extraordinary resistance to alkaline hydrolysis, has come under closer scrutiny due to unexpected and random autopolymerization while stored as a 1/1 v/v water solution at 4 degrees C (possibly due to a greater oxidability of the ether group). We have additionally found a unique degradation pathway of the monomer, called "1-6 H-transfer", by which the C1 (on the double bond site), by constantly ramming against the C6, next to the ether oxygen (O7, which in fact favors the transfer of the hydrogen atom by C1), pro…

N-Glycosylamines of 4,6-O-ethylidene-alpha-D-glucopyranose: synthesis, characterisation and structure of CO2H, Cl and F ortho-substituted phenyl deri…

2000

A saccharide based ligand suitable for metal binding (HLCOOH) has been synthesized using 4,6-O-ethylidene-alpha-D-glucopyranose (4,6-O-EGP) and anthranilic acid. A few analogous glycosylamines with chloro and fluoro ortho substitutions have also been synthesized and characterised. Complexes of HLCOOH with Na+, K+, Mg2+, Ca2+, Ba2+, Cd2+ and Hg2+ have been isolated and characterised fully. The crystal structures of 4,6-O-EGP, the chloro analogue of HLCOOH and the K+ complex of L-COOH are established. The anomeric nature, orientation of the binding core and the co-ordination aspects of K+ have been derived from these structures.

Crown-ether mediated transport of amino acids through an immobilized liquid membrane

1988

Enzymatische hydrolyse hydrophiler ester durch lipasen - eine milde carboxydeblockierung von peptiden und glycopeptiden

1993

Abstract The markedly hydrophilic 2-(N-morpholino)ethyl (MoEt) esters of protected peptides and glycopeptides are selectively and efficiently cleaved by lipases in water/acetone (10:1) at pH 7.

Evidence of a 1,4-dipole intermediate in the reaction of 1-phenyl-4-vinylpyrazole with ptad

1985

Abstract 1-Phenyl-4-vinylpyrazole reacts with 1-phenyl-1,2,4-triazoline-3,5-dione in methylene chloride to form an unstable azetidine (4). An intermediate 1,4-dipole is probably involved since, when the reaction is conducted in acetone, a 1:1:1 adduct (3) is isolated.

Influence of land use on the characteristics of humic substances in some tropical soils of Nigeria

2005

Summary In highly weathered tropical conditions, soil organic matter is important for soil quality and productivity. We evaluated the effects of deforestation and subsequent arable cropping on the qualitative and quantitative transformation of the humic pool of the soil at three locations in Nigeria. Cultivation reduced the humic pool in the order: acetone-soluble hydrophobic fraction (HE) > humic acid (HA) > humin (HU) > fulvic acid (FA), but not to the same degree at all three sites. The C and N contents, as well as the C/N ratios of humic extracts, were large and not substantially influenced by land use. The δ13C values of the humic extracts were invariably more negative in forested soil…

Enzyme class identification in cleaning products by hydrolysis followed by derivatization with o-phthaldialdehyde, HPLC and linear discriminant analy…

2008

The enzymes present in raw materials of the cleaning industry (enzyme industrial concentrates) and in household cleaners were isolated by precipitation with acetone and hydrolyzed with HCl. The resulting amino acids were derivatized with o-phthaldialdehyde, and the derivatives were separated by HPLC. The peaks of 14 amino acids were observed using a C18 column and a multi-segmented gradient of acetonitrile-water in the presence of a 5 mM citric/citrate buffer of pH 6.5. Using either normalized peak areas (divided by the sum of the peak areas of the chromatogram) or ratios of pairs of peak areas as predictor variables, linear discriminant analysis models, capable of predicting the enzyme cla…

Twisting of the resorcinarene core due to solvent effects upon crystallization

2009

The effect of the crystallization conditions on the conformation of the tetramethoxy resorcinarene skeleton was investigated in acetone solutions, to which was added a second component (less favorable solvent or salt) to promote crystallization. The resorcinarene core was found to adopt three different conformations: crown (I), a pinched crown (II) and a twisted pinched crown (III). In addition, the flexibility of the resorcinarene core was compared with a tetramethoxy resorcinarene derivative, resorcinarene bis-crown, which is in a fixed boat conformation.

Coupling Adsorption and Biological Technologies for Multicomponent and Fluctuating Volatile Organic Compounds Emissions Abatement: Laboratory-Scale E…

2015

The capacity of activated carbon as a buffer pretreatment combined with biotrickling filtration for volatile organic compound (VOC) removal has been studied. The adsorption capacity of commercial activated carbons for m-xylene, acetone and n-butyl acetate (typical paint solvents) was evaluated, including the response to the interchanging of adsorbed compounds and to mixtures over fluctuating inlet conditions. The adsorption of m-xylene and n-butyl acetate was mainly irreversible and more than three times higher than for acetone. The prior use of activated carbon influenced adsorption and buffer capacities in consecutive adsorption/desorption cycles. The Dubinin–Radushkevich equation was use…

Catalytic condensation of aromatic aldehydes with acetone on activated Mg-Al mixed oxides

2004

Abstract The factors affecting the aldol condensation of some model aromatic aldehydes (benzaldehyde, the three isomers of F-benzaldehyde and 2-naphthaldeyde) with acetone have been investigated using heterogeneous catalysts obtained by the calcination of hydrotalcite-type (HT) precursors at 773 K for 8 h, followed by rehydration at room temperature for 7 h under a flow of N 2 saturated with water vapour. At 273 K the main product was the β-hydroxy-ketone, while at 318 K it mainly dehydrated to the corresponding trans -arylideneacetone, with small amounts ( cis -arylideneacetone, 1,3-diarylideneacetone and 4-hydroxy-4-methyl-2-pentanone. High reaction times favoured the formation of trans -…