title: Synthesis and kinetic studies of a low-molecular weight organocatalyst for phosphate hydrolysis in water.
abstract: Kinetic studies of a low-molecular weight organocatalyst 1 are presented. Compound 1 contains two histidines and one cationic side chain attached to a central aromatic core. In aqueous solution 1 accelerates the hydrolysis of a prototypal phosphodiester with rate enhancements of up to two orders of magnitude. A detailed HPLC analysis of hydrolysis experiments in Bis-Tris-buffer showed that the buffer itself can act as a nucleophile at least with the cyclic phosphate 16. Compound 1 is also an efficient host for the binding of bis-(para-nitrophenyl)-phosphate 14 with extraordinary high affinity of K(ass) = 24,400 M(-1) in buffered water.
authors.affiliation: Institute for Organic Chemistry, University of Duisburg-Essen, Universitätsstrasse 7, 45141 Essen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Merschky
authors.forename: Carsten
authors.initials: C
authors.lastname: Schmuck
mesh_terms: D002384:Catalysis; D006146:Guanidines / Q000138:chemical synthesis* / Q000737:chemistry*; D006639:Histidine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008970:Molecular Weight; D010710:Phosphates / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry*
chemical_list: D006146:Guanidines; C546990:N2-(2-amino-3-(3,5-bis((2-acetamido-3-(1H-imidazol-4-yl)propanamido)methyl)-2,4,6-triethylbenzylamino)-3-oxopropyl)-N5-carbamimidoyl-1H-pyrrole-2,5-dicarboxamide; D010710:Phosphates; D014867:Water; D006639:Histidine