Fig. 1.

Baicalein is predicted to bind to PR with little conformational specificity. a Structures of known phytoprogestin compounds, apigenin and kaempferol. b Structures of tangeretin, wogonin, and baicalein which were screened for progestogenic activity. c–e Molecular docking of tangeretin, wogonin, and baicalein with PR, crystal structure PDB ID:1a28. c Top-ranked docking pose for tangeretin with PR, showing side chains of PR residues within 3.5 Å of tangeretin. PR residues include Tyr890, Leu797, Met801, Arg766, Met759, Gln725, Leu718, Leu719, and Met909. d Top-ranked docking pose for wogonin with PR, showing side chains of PR residues within 3.5 Å of wogonin. PR residues include Val760, Met801, Leu797, Tyr890, Asn719, Leu718, Gln725, Thr894, and Gly722. e Top-ranked docking pose for baicalein with PR, showing side chains of PR residues within 3.5 Å of Baicalein. PR residues include Met801, Leu797, Phe794, Asn719, Leu718, Gln725, Thr890, and Thr894