Figure 6.

Top and side views of a structural model for HXDV, in which carbon atoms are depicted in gray, oxygen atoms are depicted in red, nitrogen atoms are depicted in blue and hydrogen atoms are depicted in white. Note the nonplanar nature of the hexaoxazole torand, as highlighted by the side view. The SYBYL 7.2 software suite (Tripos Inc.) was used to build a starting 3D structure of the ligand molecule. This structure was subsequently energy minimized using the Tripos force field with 1000 iterations of the conjugate gradient method. A nonbonded cutoff of 8 Å was used in these calculations, and atomic charges were assigned based on the Gasteiger–Hückel method (82).