New dibenzo[b,e]thiepins were synthesized, characterized by elemental analysis, spectral studies (1H-NMR, 13C-NMR, IR) and
screened for their microbicidal and antibiofilm properties. The new dibenzo[b,e]thiepins and their sulfones exhibited a broad spectrum of
antimicrobial activity (superior for the S-oxidized compounds) being effective at low concentrations against a wide range of infectious
microorganisms. The oximes exhibited anti- A. baumanii activity.
Some of the compounds exhibited good antibiofilm activity against the Gram-negative, non-fermentative bacilli P. aeruginosa and A.
baumanii, and their possible target suggested by molecular modeling being the synthesis of the quorum sensing molecules employed by
the Gram-negative microorganisms represented by N-acyl-l-homoserine lactones.