Interactions and Catalysts of ATP and Other Organophosphorous Esters in Bile Salt Systems
Abstract
Adenosinetriphosphate (ATP), bis-p-nitrophenyl phenylphoshonate (bis-PNPP) and tris-p-nitro-phenylphosphate were studied in bile salt systems. ATP showed essentially no solvolysis in dimethyl sulfoxide (DMSO) or water systems with sodium cholate (NaC). Rate constants for the solvolysis of bis-PNPP in DMSO in the presence of aggregated NaC are enhanced by factors of more than 5 million fold and 1.89x10?? fold with respect to those in the pure bulk solvent and in water systems. The observed rate constant for the formation of p-nitrophenoxide ion exibits a sigmoidal dependence with increasing NaC concentrations reaching a plateau at high NaC concentrations. No kinetic deuterium solvent isotope effects were observed and no reaction occurs in the presence of methyl cholate. A mechanism for the bile salt catalysis is proposed and discussed in terms of both physical and chemical interactions for bis-PNPP. Tris-PNP showed the same trends as bis-PNPP but data was not analyzed completely for this paper.
Description
Program year: 1977-1978Digitized from print original stored in HDR
Subject
Adenosinetriphosphatesolvolysis
bile salt catalysis
bis-p-nitrophenyl phenylphoshonate
sodium cholate
dimethyl sulfoxide
Citation
Jarmek, George E. (1978). Interactions and Catalysts of ATP and Other Organophosphorous Esters in Bile Salt Systems. University Undergraduate Fellows. Available electronically from https : / /hdl .handle .net /1969 .1 /CAPSTONE -JarmekG _1978.