3d image of estrane skeletal formula

estrane steroid gonane nandrolone estratrienes estrins double bonds estrogen hormones estradiol hormone hormonal therapy replacement function action endocrine endocrinology level prohormone analogue steroidal endogenous synthetic semisynthetic metabolite biosynthesis mechanism biosynthetic intermediate biogenesis substrate precursor synthesis derivative bioprecursor metabolic molecule molecular formula skeletal structural structure biomolecule bioactive biochemical 3d