PART I. THE KINETICS AND MECHANISM OF THE CONVERSION OF ALIPHATIC AMIDES TO AMINES WITH I,I-BIS(TRIFLUOROACETOXY)IODOBENZENE. PART II. SPECIFIC CLEAVAGE OF PROTEINS AT ASPARTIC ACID (METHYLENEDIAMINE, TRYPSIN, ISOCYANATE)
Abstract
Part I. The reagent I,I-bis(trifluoroacetoxy)iodobenzene was found to convert aliphatic amides to amines of one less carbon by an oxidative rearrangement. The kinetics of the reaction was studied in the pH range 1.8 to 3.0. The rate of rearrangement was found to increase with increasing pH, and decreases with added trifluoroacetic acid. The reversible formation of an intermediate was proposed which accounts for the kinetic data. A dimeric form of the reagent, (mu)-oxo-I,I'-bis(trifluoroacetoxy)diphenyldiiodine was isolated and characterized. This dimer was proposed to be the active form of the reagent. The association constant for the dimer was determined. Part II. The side-chain carboxylic acid function of an aspartic acid containing tripeptide was converted into a trypsin substrate. This conversion required the coupling of a protected form of methylenediamine to the free carboxylic acid. The kinetics of the reaction with trypsin were studied. The rate is pH dependent, and the maximum rate was found to occur at pH 7.10. The corresponding lysine and modified glutamic acid containing peptides were also studied. The coupling reaction with the protected diaminomethane gave low yields, and the products required extensive purification.
Degree
Ph.D.
Subject Area
Pharmacology
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