a 7 , 2 ″- dehydrate puerarin represented by formula and salt derivatives thereof . the compounds are prepared from puerarin by intramolecular mitsunobu reaction . they are capable of shortening arrhythmia duration and prolonging coagulation time . they can be prepared into oral formulations or injections for treatment of cardiovascular and cerebrovascular diseases including arrhythmia , coronary heart disease , angina pectoris , myocardial infarction , and cerebral infarction .