Five trisubstituted quinazolones and eight trisubstituted quinazoline-4-thiones have been tested for antibacterial effects by a microdilution method. Four derivatives exerted a significant effect on E. coli, P. aeruginosa, S. aureus and B. subtilis (IC50 < 100 mg/L). In the bacterium P. aeruginosa six quinazolines showed a higher antibacterial effect than ampicillin. The most sensitive to the effects of the quinazolines was S. aureus; a concentration of 100 mg/L of six derivatives induced a bacteriostatic effect on S. aureus. The quinazoline-4-thiones were generally more active than the quinazolones. All the tested concentrations of the four most effective quinazolines influenced the specific growth rate.

• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Bacillus subtilis drug effects   MeSH
• Bacteria drug effects   growth & development   MeSH
• Quinazolines chemistry   pharmacology   MeSH
• Escherichia coli drug effects   MeSH
• Microbial Sensitivity Tests MeSH
• Pseudomonas aeruginosa drug effects   MeSH
• Staphylococcus aureus drug effects   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Quinazolines MeSH

Two synthetic 2,6-disubstituted 4-anilinoquinazolines exerted a significant effect on the G+ bacteria Bacillus subtilis and staphylococcus aureus. None of 12 tested derivatives influenced Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. Derivatives having the aromatic ring non-substituted or substituted by bromine, the pyrimidine ring by phenyl, morpholine or piperidine and the aniline skeleton non-substituted or substituted by methyl or amino group exerted a considerable antibacterial activity.

• MeSH
• Aniline Compounds chemistry   pharmacology   MeSH
• Anti-Bacterial Agents chemistry   pharmacology   MeSH
• Drug Resistance, Microbial MeSH
• Bacillus subtilis drug effects   MeSH
• Quinazolines chemistry   pharmacology   MeSH
• Microbial Sensitivity Tests MeSH
• Staphylococcus aureus drug effects   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Aniline Compounds MeSH
• Anti-Bacterial Agents MeSH
• Quinazolines MeSH

Eight 4-quinazolylhydrazines and eleven their arylhydrazones have been tested for antibacterial effects and for structure-activity relationships by a modified microdilution method. The derivative 6-chloro-2-morpholino-4-quinazolyl-5'-nitro-2'-furylhydrazone++ + had the highest antibacterial effect, the MIC values being 100 mg/L for E. faecalis, 250 mg/L for S. aureus, 200 mg/L for P. aeruginosa and 350 mg/L for E. coli. The most effective derivatives were those with the benzene ring substituted with chlorine or methyl group in position 6 or 8 and with pyrimidine ring substituted with a secondary amine in position 2. The modified microdilution method did not give rise to any statistically significant deviations in the MIC values for ampicillin in comparison with reported reference collection values.

• MeSH
• Anti-Bacterial Agents chemistry   pharmacology   MeSH
• Quinazolines chemistry   pharmacology   MeSH
• Enterococcus faecalis drug effects   MeSH
• Escherichia coli drug effects   MeSH
• Hydrazines chemistry   pharmacology   MeSH
• Microbial Sensitivity Tests * MeSH
• Microchemistry MeSH
• Pseudomonas aeruginosa drug effects   MeSH
• Staphylococcus aureus drug effects   MeSH
• Structure-Activity Relationship MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Quinazolines MeSH
• Hydrazines MeSH