Hydrogen bond lengths (Å) and calculated van der Waals interaction energy (Δ<i>E</i><sub>VDW</sub>, kcal/mol) and Coulomb interaction energy (Δ<i>E</i><sub>Coulomb</sub>, kcal/mol) between estrogen derivatives and the ERα and ERβ LBDs.
<p>Hydrogen bond lengths were quantified by measuring distances between the hydrogen atoms of the 3-hydroxyl group of estrogen derivatives and the O<sub>ε</sub> of ERα-E353 or ERβ-E305, between the oxygen atoms of the 3-hydroxyl group of estrogen derivatives and the H<sub>η</sub> of ERα-R394 or ERβ-R346 and between the hydrogen atoms of 17-hydroxyl group of estrogen derivatives and N<sub>δ</sub> of ERα-H524 or ERβ-H475. For the <i>D</i>-ring derivatives, two hydrogen bond lengths were listed. The first is formed by hydrogen atoms of 17-hydroxyl groups and the second is formed by hydrogen atoms of 16-hydroxyl groups. Relative binding affinity (<i>RBA</i>) was also listed for comparison.</p
