2-Methoxyestradiol- 13 C,d 3 is the 13 C- and deuterium labeled 2-Methoxyestradiol. 2-Methoxyestradiol (2-ME2), an orally active endogenous metabolite of 17β-estradiol (E2), is an apoptosis inducerand an angiogenesis inhibitor with potent antineoplastic activity. 2-Methoxyestradiol also destablize microtubules. 2-Methoxyestradio, also a potent superoxide dismutase ( SOD ) inhibitor and a ROS-generating agent, induces autophagy in the transformed cell line HEK293 and the cancer cell lines U87 and HeLa.