Premium
Calculation of energies of protonation and tautomerization of methyl histamines and their relationship with p K a values and biological activities
Author(s) -
XiaoYuan Fu,
ShuJun Su
Publication year - 1981
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560200717
Subject(s) - tautomer , chemistry , cndo/2 , protonation , histamine , computational chemistry , aqueous solution , thermodynamics , stereochemistry , organic chemistry , molecule , ion , medicine , physics
The protonation energies (pE) of histamine and methyl histamines were calculated by using the CNDO/II method. After correction for hydration energies, the variation of the pE values has the same trend as that of the p K a 1 , values determined in aqueous solution. However, there is no apparent relation between the calculated pE and the biological activities for the above‐mentioned compounds. On the other hand, it was found that the relative stability of the two tautomers did reflect the H 2 ‐receptor agonist activities. The smaller the energy of the N(1)—H tautomer, the greater its H 2 ‐receptor activity.