Figure 4. Inter and intra molecular interactions provide rigidity to the spacer connecting rings A and B.

Anionic carboxyl oxygen atom of FSHP_FB (gray sticks) is involved in intramolecular hydrogen bond formation with hydroxyl group present at the ortho-position of Ring A and also forms salt bridge with 104K (orange stick) of hFSHR (green cartoon). The interactions are shown in black dotted lines.