It was shown in the preceding paper that incubation of the rabbit polymorphonuclearleukocyteswith phosphonate esters leads to an irreversible inhibition of the ability of the leukocyte to respond to the chemotactic factor. This "cell-dependent inhibition" was attributed to the inactivation by the phosphonates of an esterase existing in or on the leukocyte in an already activated state. As shown...

BACKGROUND Heterobifunctional cross-linking agents are useful in both protein science and organic synthesis. Aminolysis of reactive esters in aqueous systems is often used in bioconjugation chemistry, but it must compete against hydrolysis processes. Here we study the kinetics of aminolysis and hydrolysis of 2-S-phosphorylacetate ester intermediates that result from displacement of bromide by a...

Pentacyclic triterpenol methyl ethers (PTMEs), germanicol methyl ether (miliacin), 3-methoxyfern-9(11)-ene (arundoin), beta-amyrin methyl ether (iso-sawamilletin), and 3-methoxytaraxer-14-ene (sawamilletin or crusgallin) were characterized in surface sediments of the Cross-River system using gas chromatography-mass spectrometry (GC-MS). Triterpenol esters (mainly alpha- and beta-amyrinyl acetat...

The use of iodine as a catalyst and either acetic or trifluoroacetic acid as a derivatizing reagent for determining the enantiomeric composition of acyclic and cyclic aliphatic chiral alcohols was investigated. Optimal conditions were selected according to the molar ratio of alcohol to acid, the reaction time, and the reaction temperature. Afterwards, chiral stability of chiral carbons was stud...

N-Alkyl perfluorooctane sulfonamides have been widely used as surfactants on fabrics and papers, fire retardants, and anticorrosion agents, among many other commercial applications. The broad use, global distribution, and environmental persistence of these compounds has generated considerable interest regarding potentially toxic effects. We have previously reported that perfluorooctanesulfonami...

Esters constitute a broad family of volatile compounds impacting the organoleptic properties many beverages, including wine and beer. They can be classified according to their chemical structure. Higher alcohol acetates differ from fatty acid ethyl esters, whereas third group, substituted contributes fruitiness red wines. Derived yeast metabolism, biosynthesis higher esters has been widely inve...

Surface and interfacial tensions with hexadecane were measured for water soluble maltodextrin and starch ester solutions in order to determine heir potential as stabilizers or emulsifiers. The surface tension for an acid hydrolysed starch (maltodextrin) initially declined with concentration nd then reached an equilibrium value of 56 mN/m at 20–40 wt.%, suggesting that hydrated starch has this s...

BACKGROUND Early defoliation is a very innovative technique in viticulture used for yield management. The effects of early leaf removal performed manually and mechanically at two different phenological stages, pre-bloom and fruit set, on the volatile composition of Tempranillo (Vitis vinifera L.) wines were studied. Volatiles were identified and quantified by gas chromatography. RESULTS Early...

Cellulose derivatives are promising bio-based polymeric materials with possible applications ranging from thickening agents and stabilizers to optical films. The precise determination of their degree substitution (DS) is crucial, as the DS substantially influences material properties such cellulose derivatives. Herein, applicability attenuated total reflection-Fourier transform infrared for est...