a22 (antibiotic) a22 (antibiotic) a22, also known as s-(3,4-dichlorobenzyl) isothiourea, is a chemical compound with antibiotic activity. it is colorless, hygroscopic, and light-sensitive. a22 names preferred iupac name (3,4-dichlorophenyl)methyl carbamimidothioate other names 3,4-dichlorobenzyl carbamimidothioate identifiers cas number 22297-13-8 3d model (jsmol) interactive image chembl chembl1229059 pubchem cid 348494 comptox dashboard (epa) dtxsid10324845 inchi inchi=1s/c8h8cl2n2s/c9-6-2-1-5(3-7(6)10)4-13-8(11)12/h1-3h,4h2,(h3,11,12)key: lztcfldzlboldw-uhfffaoysa-n smiles c1=cc(=c(c=c1csc(=n)n)cl)cl properties chemical formula c8h8cl2n2s molar mass 235.13 g·mol−1 except where otherwise noted, data are given for materials in their standard state (at 25 °c , 100 kpa). infobox references antibiotic activity a22 acts as a reversible inhibitor of the bacterial cell wall protein mreb, causing bacterial rod-shaped cells to form coccoid cells. the antibiotic activity of a22 has been studied primarily in pseudomonas aeruginosa. however, a22 does not seem to be useful as an antibiotic in humans due to its cytotoxic and genotoxic effects on human peripheral blood mononuclear cells (pbmcs). a22 as a research tool despite its cytotoxic effects in human cells, a22 has been used as a research tool to investigate the bacterial cytoskeleton. a22 binds directly to the actin homolog mreb in its nucleotide-binding pocket, blocking simultaneous atp binding. as a consequence, a22 inhibits mreb polymerization and thus disrupts the cytoskeleton of bacteria, causing defects of morphology and chromosome segregation.