Some N-(5-methyl-1,3,4-thiadiazol-2-yl)-4-[(3-substituted)ureido/ thioureido]benzenesulfonamides as carbonic anhydrase I and II Inhibitors

According to the recent studies it has been proved that the solid tumors’ extracellular pH is more acidic than the normal tissue. However, the intracellular pH is similar to normal cells or even a bit more basic. To regulate the pH gradient between the intracellular and extracellular compartments the tumour cells excrete ion transport proteins, such as, H+ATPase, Cl-/ HCO3 exhanger etc (1). Many tumours also express CAs, the Zn (II) dependent enzymes catalyzing the hydration of carbon dioxide to from bicarbonate and a proton (2-4).