I. The Synthesis of Pyridine and Pyridine 1-Oxide Substituted Alanine Derivatives. II. Preliminary Investigations of Alpha-Chymotrypsin Catalyzed Hydrolyses of Acylated Amino Acid Esters at Low Enzyme Concentrations -- Studies of Surface Effects. Ill. The Synthesis and Rate of Acetolysis of 1-Bicyclo[2.2.11 Heptylmethyl Tosylate
Author: Bixler, Robert L.
Year: 1957
Degree: Dissertation (Ph.D.)
Advisor: Niemann, Carl G.
Committee Member: Unknown, Unknown
Option: Chemistry; Chemical Engineering
DOI: 10.7907/8PDN-2835
Abstract
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Methods for the preparation of pyridine and pyridine 1-oxide substituted alanines for use as substrates for the enzyme alpha-chymotrypsin were studied. As a consequence of this work, N-benzoyl-L-4-pyridylalanine 1-oxide methyl and ethyl esters, N-acetyl-DL-4-pyridylalanine 1-oxide methyl ester, and N-(nicotinyl 1-oxide)-L-phenylalanine methyl ester were prepared. The method for the synthesis of 4-pyridyl-alanine via a malonic ester condensation has been improved to the point where it is preparatively useful.
It has been demonstrated that the catalytic reduction of pyridine 1-oxides in water with a platinum catalyst is nonspecific, the pyridine and pyridine 1-oxide groups being reduced at comparable rates.
A kinetic study of the effect of surface on alpha-chymotrypsin catalyzed hydrolyses of acylated amino acid esters was carried out. It was shown that there was no effect of surface on the kinetics, varying the surface by a factor of 3000. However, it was shown that serious losses of enzyme can occur during transfer operations at an enzyme to surface ratio of [...] or greater. The possibility of avoiding these losses of enzyme during transfer by adding a "carrier" for the enzyme, in the form of colloidal silica, was investigated, and shown to have promise. It was shown that the enzyme was adsorbed on colloidal silica.
Bicylo[2.2.1]hepty1methyl tosylate has been prepared, and its rate of acetolysis at 99[degrees]C. determined.
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