Pre-steady state kinetic parameters pertaining to chymotrppsin-catalyzed hydrolysis of specific substrate esters can be obtained from measurements of the displacement of the competitive inhibitor proflavin from enzyme by substrate. This method, which was previously used in experiments with specific substrate amides, has now been applied to the investigation of N-acetyl-L-phenylalanine methyl es...

Enzyme-substrate binding constants, K’e, for chymotrypsin and specific amide (N-acetyl-Mryptophanamide and Nacetyl-L-phenylalaninamide) and ester (N-acetyl-L-tryptophan ethyl ester) substrates have been measured by a proflavin-displacement method. Also, the rate constant for the formation of one intermediate in the chymotrypsincatalyzed hydrolysis of the ester has been determined at selected pH...

Abstract Pectin from two different plant sources: apple and sugar beet was studied. Apple pectinwas modified by chemical treatments such as: acid, alkali and ammonia, so as to obtain an ester levelequal to or less than 50 %, which is described as low methoxyl (LM) pectin. LM pectin form gelswith significant characteristic. In this study, de-esterification of apple pectin with acid treatmentresu...

How chemical structure changes affect the curing reactions and thermal properties of 2,2 -bis(4-cyanatophenyl) propane (cyanate ester) cured rigid-rod epoxy resins has been studied for biphenol and tetramethyl biphenol epoxies. The formation of an oxazolidinone ring is the dominant curing reaction for biphenol epoxy, whereas the formation of a cyanurate ring is the dominant curing reaction for ...

This paper describes the production of 5,9,13-trimethyltetradeca-4E,8E,12-trienyl-5,9,13-trimethyltetradeca-4E,8E,12-trienoate during the aerobic degradation of squalene by a Marinobacter strain, 2Asq64, isolated from the marine environment. A pathway involving initial cleavage of the C(10)-C(11) or C(14)-C(15) double bonds of the squalene molecule is proposed to explain the formation of this p...

During our studies toward the synthesis of ABC ring system hexacyclinic acid, we observed an unexpected influence steric bulk ester group Michael acceptor in a key conjugate addition. We propose eight-membered transition state to explain formation undesired diastereomer case unhindered esters.