Sulfenamide and sulfonamide derivatives of metformin can exert anticoagulant and profibrinolytic properties.

Type 2 diabetes mellitus (T2DM) is characterised not only by hyperglycaemia and insulin resistance but also an impaired balance between the processes of coagulation and fibrinolysis. The aim of this study was to examine the effects of metformin, a widely-used oral anti-diabetic drug, phenformin and eight sulfenamide and sulfonamide derivatives of metformin on several haemostasis parameters. Thrombin Time (TT) tests were performed according to the available commercial method. The activity of factor X was conducted based on deficient plasma factor X. The activity of two main enzymes involved in haemostasis, thrombin and plasmin, was measured spectrophotometrically with chromogenic substrates. Protein C and antithrombin III (AT) activity assays using chromogenic substrates were conducted to determine the effect of the derivatives of metformin on these both naturally occurring anticoagulants. Two of the compounds, sulfenamide with hexyl tail and para-nitro-benzenesulfonamide significantly shortened TT. ortho-nitro sulfonamide at a concentration of 0.3-1.5 μmol/mL contributed to a significant decrease in the activity of factor X. However, sulfenamides with cyclohexyl, butyl and branched ethyl-hexyl tails at 1.5 of μmol/mL increased its activity, and simultaneously shortened PT. Additionally, ortho-nitro-benzenesulfonamide at concentrations of 1.5 μmol/mL was found to significantly decrease reaction velocity (↓ dA/dt) in the thrombin activity assay. On contrary, it was noticed that branched sulfenamide at the concentration of 1.5 μmol/mL significantly increased the enzymatic activity of plasmin. Metformin, phenformin and octyl and butyl sulfenamides were associated with a significant increase in the activity of AT. Hexyl sulfenamide and para-nitro- as well as para-trifluoro-ortho-nitro-benzenesulfonamide contributed to the decrease in the activity of protein C, while the other tested compounds did not affect its activity. In conclusion, 2-nitro-benzenesulfonamide derivative of metformin presents highly beneficial anticoagulant properties. This compound is therefore promising candidate for further in vitro and in vivo studies.