Abstract
During the past years, a growing number of bacterial strains have become resistant
to tetracyclines. The problem of increasing resistance and lack of susceptibility
to tetracyclines applies to strains isolated from both: animals and humans. Basic
tools to design new drugs and determining the direction of the search for new molecules
is the analysis of the relationship between the chemical structure and the pharmacokinetic
and pharmacodynamic parameters. Purpose of this study is to determine the relationship
between physicochemical parameters of tetracyclines and MIC50 and MIC90 values determined for Streptococcus spp. Analysis of physicochemical parameters of selected drugs was made using MarvinSketch
5.11.5 (ChemAxon Ltd.) and QuickProp 3.1 software from Schrödinger package v 31207.
MIC50 and MIC90 values were correlated with 51 calculated physicochemical parameters and arithmetic
expressions. Internal and external model validation was performed using leave-one
out method. 4 arithmetic expressions fulfilled all validation criteria, but only in
relation to MIC50. A new method to optimize the tetracyclines’ structure in relation to Streptococcus spp. was presented. It was also shown that the relations of structure: antimicrobial activity
type can have different nature depending on MIC50 or MIC90 of specific bacterial strain.
Key words
in silico
- MIC - tetracycline - validation - structure