Synthesis and studies on antibacterial activity of pyrido[3,2-e]-1,2-thiazines and related derivatives.

Twenty of the known and newly synthesized derivatives of pyrido-1,2-thiazine derivatives 3-7, which represent a novel class of potential antibacterial agents, were evaluated against strains of Mycobacterium fortuitum (PCM 672) and Staphylococcus aureus (PCM 2602). The pilot experiments showed that the compounds in an initial in vitro microbiological evaluation were not efficient antibacterial agents, whereas some of them unexpectedly promoted replication of the microorganisms in the range of 10-50% even at sub-mg/mL concentrations.