This work was devoted to the study of pharmacological properties of 2- mercaptobenzimidazole (I), 2-mercaptobenzoxazole (V), 2-mercaptobenzothiazole (IX), their S-carboxymethyl derivatives (1I, VI, X), and the salts of these derivatives with morpholine (III, VII, XI) and triethanolamine (IV, VIii, XII):~ xg"-. sR