2,2-Dihydroxyazobenzene is a small molecule inhibitor of ADP ribosyl cyclase and it attenuates angiotensin (Ang) II-induced hypertrophic responses. 2,2-Dihydroxyazobenzene is formed during the oxidation of diclofenac by myeloperoxidase/hydrogen peroxide. 2,2-Dihydroxyazobenzene was used as complexing reagent in determination of aluminum in human serum by ion-pair reversed-phase partition HPLC. 2,2-Dihydroxyazobenzene is a small molecule inhibitor of ADP ribosyl cyclase and it attenuates angiotensin (Ang) II-induced hypertrophic responses. 2,2-Dihydroxyazobenzene is formed during the oxidation of diclofenac by myeloperoxidase/hydrogen peroxide. 2,2-Dihydroxyazobenzene was used as complexing reagent in determination of aluminum in human serum by ion-pair reversed-phase partition HPLC.