The Lopukhin family was a noble family of the Russian Empire, forming one of the branches of the Sorokoumova-Glebov family. One of its members, Eudoxia Lopukhina, married Peter the Great. When Pyotr Lopukhin's son died childless, the family's princely title passed to
Eudoxia had no children.
We know that her son died childless, but she must have had children if she had a son.