Compounds of formula (I): wherein R1 and R4 are OR7, R2 and R3 are H or OR7, with the proviso that when R2 is OR7 then R3 is H, and when R3 is OR7 then R2 is H； R5 and R6 are independently H, OH, or OR7 with the proviso that when R5 is OH, R6 is not OH； R7 is alkyl, aryl or arylalkyl； the drawing "(a)" represents either a single or a double bond； or pharmaceutically acceptable salt(s) or prodrug(s) thereof are disclosed. These novel compounds are useful of treatment, prophylaxis, amelioration, or defence against and / or prevention of hormonal dependent conditions, cancer, and diseases and conditions associated with oxidant stress.
