Antimicrobial agents

The antimicrobial effectivity of 32 derivatives and analogues of 10-(4-methylpiperazino)-10,11-dihydrodibenzo(b,f)thiepine was investigated and it was found that substituents in rings A and C and in the piperazine residue affect the antimicrobial potency of the compound. The derivative with the chlorine atom in position 3 was found to be most active in suppressing microbial growth. Substitution with chlorine of the ring C in positions 6, 7 and 8 produced derivatives with highest tuberculostatic activity. The growth of Gram-negative microorganisms (with the exception ofKlebsiella pneumoniae), as well as of fungiTrichophyton mentagrophytes, Candida albicans andAspergillus niger, was not suppressed by any of the derivatives. The antimicrobial effect of the active derivatives was demonstrated on strains ofStreptococcus haemolyticus, Staphylococcus pyogenes aureus, Mycobacterium tuberculosis, Klebsiella pneumoniae andSaccharomyces pastorianus.