Table 2 Electronic and structural parameters of cinchona alkaloids in aqueous solvent, based on the common pharmacophores described for (-) mefloquine and quinine and (+) mefloquine and quinidine by Karle & Karle [17]. (*dipole moment calculated for free base).
drug in water | MM+ energy <0.004 | dipole moment* | proton affinity | O12-N1 | N1-C5' | ring-O12 torsion° | O12-N1 torsion° | H8-C8-C9-H9 dihedral° | H-N1-C9-O12 torsion° |
|---|---|---|---|---|---|---|---|---|---|
| Â | Kcal/mole | Debye | Kcal/mole | Ã… | Ã… | Â | Â | Â | Â |
Q | 11.9 | 1.88 | 208.85 | 3.14 | 4.1 | 157.8 | -83.8 | -82.6 | -123.2 |
EQ | 15.5 | 2.44 | 213.36 | 2.77 | 4.7 | 40.6 | 43.3 | 174.0 | -5.9 |
QD | 18.9 | 1.66 | 208.61 | 3.09 | 4.2 | -161.1 | 78.2 | 74.7 | 104.4 |
EQD | 12.8 | 2.21 | 213.84 | 2.82 | 4.7 | -43.2 | -49.1 | -175.8 | 0.6 |
CD | 11.1 | 1.15 | 209.38 | 3.21 | 4.2 | 144.9 | -91.0 | -86.8 | -129.6 |
ECD | 13.6 | 1.54 | 213.88 | 2.79 | 4.6 | 45.1 | 46.0 | 175.0 | -5.9 |
C | 10.9 | 0.96 | 209.78 | 3.19 | 4.1 | -156.0 | 88.9 | 85.3 | 118.3 |
EC | 13.5 | 1.27 | 213.75 | 2.85 | 4.7 | -45.4 | -50.2 | -176.2 | -2.5 |
HQ | 10.4 | 2.08 | 209.39 | 3.20 | 4.1 | 156.1 | -83.6 | -82.8 | -123.6 |
HQD | 10.7 | 1.79 | 209.75 | 3.23 | 4.2 | -152.7 | 89.5 | 88.8 | 118.6 |