New isoflavones from Gynandriris sisyrinchium and their antioxidant and cytotoxic activities

Abstract Chemical investigation of Gynandriris sisyrinchium (L.) Parl growing in Jordan resulted in the isolation and characterization of a total of twelve compounds two of which are reported here for the first time in nature. These new compounds included the isoflavones; 3′-methyl tenuifone ( 2 ) and gynandrinone ( 5 ). In addition, ten known compounds including; β-sitosterol ( 1 ), 7,3′-dimethoxy-5,6,4′-trihydroxyisoflavone ( 3 ), iristectorigenin ( 4 ), hispidulin ( 6 ), galangustin ( 7 ), 6-hydroxybiochanin A ( 8 ), ursolic acid ( 9 ), ladanetin ( 10 ), 4′-O-methylgenistein ( 11 ) and β-sitosterol glucoside ( 12 ) are also reported here for the first time from G. sisyrinchium . The isolated compounds were characterized by different spectroscopic methods including NMR (1D and 2D), UV, IR and MS (HRESIMS and EIMS). The antioxidant and cytotoxic activities of isoflavones 2 , 3 and 5 were investigated. Compound 3 showed the highest antioxidant activity (IC 50  = 17.3 μg/mL), as compared to compounds 5 and 2 (IC 50  = 26.7 and 51.7 μg/mL, respectively). The cytotoxic activity against the human promyelocytic leukemia HL-60 cells revealed that compound 2 was the most active (40 μM). The results indicate that the cytotoxicity of compound 2 is mediated by apoptosis.