Bulky organosilicon compounds based on sulfanyltetrazoles: their synthesis and in vitro antibacterial evaluation

The study introduces different organosilicon derivatives incorporating sulfanyltetrazole ring for biological applications. Initially, the sulfanyltetrazole derivatives and halo-analogues (Br, I) were synthesized. Later, selective reaction of tris(trimethylsilyl)methyllithium (TsiLi) in the presence (-46 and 0 degrees C) and absence (room temperature) of CS2 with halo-sulfanyltetrazole derivatives yielded new multifunctional sulfanyltetrazole regioisomers with SH, C = S, ethynylthio and SiMe3 groups, respectively. All the synthesized compounds were characterized by IR, H-1-NMR, C-13-NMR spectra and elemental analysis data. The compounds were screened for their antibacterial activities against clinically important gram-positive and gram-negative bacteria using the spectrophotometric microdilution method. The preliminary screening indicated that the organosilicon derivatives incorporating SH and C = S (mercapto-silyl-thiones) and silyl-thioalkynes have antibacterial activities, whereas no antibacterial activity was observed on compounds containing (Me3Si)(3)C groups. Of the synthesized compounds, compound 5d showed the best activity against all the tested organisms (3.91-31.25 mu g/mL).