An investigation of chlorophenol proton affinities and their influence on the biological activity of microorganisms.
The proton affinities of 15 chlorophenols are calculated by ab initio methods. Straight correlation between proton affinities and changes in the electronic structure is observed. The proton affinities decrease linearly with the electronic density gain on the chlorine atoms, as the liberation of the proton increases. To confirm the importance of the proton affinities on the toxicity of chlorophenols, calorimetric responses of these molecules and related ones where the acid proton is changed to a methyl group (anisol and its chlorinated derivatives) were used to verify their effects on Chromobacterium violaceum. The results confirmed that the chlorophenols are more toxic than the respective chloroanisols and suggest that high proton affinities are associated with low toxic activity. The toxicity of the chlorophenols can be associated with the respiratory mechanism in some microorganisms.
Basheer
Muftah M
MM
Instituto de Química, Universidade Estadual de Campinas, Barão Geraldo, 13084-971 Campinas, São Paulo, Brazil CP 6154.
Custodio
Rogério
R
Volpe
Pedro L O
PL
Rittner
Roberto
R
D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology; D002733:Chlorophenols / Q000737:chemistry* / Q000494:pharmacology*; D002861:Chromobacterium / Q000187:drug effects; D004583:Electrons; D008956:Models, Chemical; D011522:Protons; D013329:Structure-Activity Relationship
D000900:Anti-Bacterial Agents; D002733:Chlorophenols; D011522:Protons