protein tyrosine phosphatase inhibitor a of the invention lies in the manufacture of a medicament in particular a pharmaceutical composition for the treatment and prevention of diabetes obesity and cancers when it is used as a medicament this compound can either be used directly or in the form of a pharmaceutical composition the pharmaceutical composition may contain 0 1 to 99 preferably 0 5 to 90 of the compound of the invention and the balance of pharmaceutically acceptable carriers or excipients which are non toxic and inert to human and animals the pharmaceutically acceptable carriers or excipients may be one or more selected from the group consisting of fillers of solid semi solid and liquid diluents or auxiliaries for drug products the pharmaceutical composition is administered in the form of dosage per unit body weight the medicament of the invention may be administered orally or by injection intravenous or intramuscular injection oral administration may employ solid or liquid formulations thereof such as powders tablets dragees capsules solutions syrups and dropping pills injection administration may employ solid or liquid formulations thereof such as powder injections and solution injections in the case of parenteral administration for human body in order to achieve optimal effects it is advantageous to employ an amount ranging from 0 1 to 10 000 u03bcg.