Table 1.
Descriptors of chemical space consisting of sc-PDB-derived ligands and ACD-SC-derived ordinary molecules and corresponding loadings (Varimax normalized) for the first two factors*
| Descriptors | Characterization | Factor loadings | Software | |
| 1 | 2 | |||
| AREA | Total molecular surface area | 0.974 | 0.103 | Sybyl |
| PSA | Polar molecular surface area | 0.255 | 0.892 | |
| PV | Polar molecular volume | 0.501 | 0.741 | |
| VOL | Total molecular volume | 0.991 | 0.062 | |
| MOLWEIGHT | Molecular weight | 0.958 | 0.206 | |
| Acceptor | H-bond acceptor counts | 0.464 | 0.799 | |
| Donor | H-bond donor counts | 0.376 | 0.817 | |
| BondCount | Total bond counts | 0.972 | 0.060 | |
| Chiral | Counts of chiral center | 0.367 | 0.617 | |
| Hydrophobe | Hydrophobic fragment counts | 0.767 | -0.417 | |
| RingCount | Ring counts | 0.686 | -0.069 | |
| RotBonds | Number of rotatable bonds | 0.630 | 0.428 | |
| HeavyAtoms | Number of non-H atoms | 0.978 | 0.149 | |
| Carbons | Number of carbons atoms | 0.943 | -0.228 | Perl |
| Oxygens | Number of oxygen atoms | 0.425 | 0.793 | |
| Nitrogens | Number of nitrogen atoms | 0.475 | 0.324 | |
| Sulfurs | Number of sulfur atoms | 0.141 | -0.009 | |
| Phosphorus | Number of phosphorus atoms | 0.162 | 0.617 | |
| Halides | Number of halide atoms | 0.076 | -0.170 | |
| DoubleBonds | Number of double bonds | 0.527 | 0.378 | |
| TripleBonds | Number of triple bonds | -0.009 | -0.109 | |
| RadOfGyration | Radius of gyration | 0.888 | 0.004 | Cerius 2 |
| ShadowXY | Surface area projections | 0.967 | 0.076 | |
| ShadowXZ | 0.951 | 0.053 | ||
| ShadowYZ | 0.877 | 0.093 | ||
| ShadowXYfrac | -0.610 | -0.027 | ||
| ShadowXZfrac | -0.421 | -0.002 | ||
| ShadowYZfrac | -0.289 | 0.039 | ||
| Shadownu | 0.268 | -0.117 | ||
| ShadowXlength | 0.849 | -0.008 | ||
| ShadowYlength | 0.798 | 0.075 | ||
| ShadowZlength | 0.756 | 0.059 | ||
| Density | Density | -0.089 | 0.354 | |
| PMImag | Principal moment of inertia | 0.819 | 0.134 | |
| AlogP | Log of the partition coefficient using Ghose and Crippen's method. | 0.425 | -0.727 | |
| AlogP98 | Log of the partition coefficient, atom-type value, using latest parameters. | 0.365 | -0.852 | |
| Fh2o | Desolvation free energy for water | -0.479 | -0.762 | |
| Foct | Desolvation free energy for octanol | -0.578 | -0.617 | |
| LogP | Log of the partition coefficient. | -0.022 | -0.892 | |
| MR | Molar refractivity using Hopfinger's method. | 0.835 | -0.110 | |
| MolRef | Molar refractivity using linear additive method based on AlogP atom types | 0.986 | -0.033 | |
| JX | Balaban indices | -0.567 | 0.027 | |
| Kappa1 | Kappa topological indices | 0.969 | 0.189 | |
| Kappa2 | 0.926 | 0.026 | ||
| Kappa3 | 0.691 | 0.033 | ||
| Kappa1AM | 0.958 | 0.220 | ||
| Kappa2AM | 0.901 | 0.050 | ||
| Kappa3AM | 0.630 | 0.046 | ||
| PHI | Molecular flexibility index | 0.800 | 0.078 | |
| SC0 | Subgraph topological counts | 0.980 | 0.147 | |
| SC1 | 0.973 | 0.125 | ||
| SC2 | 0.943 | 0.186 | ||
| SC3P | 0.904 | 0.141 | ||
| SC3C | 0.749 | 0.389 | ||
| SC3CH | 0.016 | -0.086 | ||
| CHI0 | Kier and Hall Chi connectivity indices | 0.974 | 0.190 | |
| CHI1 | 0.983 | 0.115 | ||
| CHI2 | 0.958 | 0.210 | ||
| CHI3P | 0.939 | 0.136 | ||
| CHI3C | 0.655 | 0.484 | ||
| CHI3CH | 0.015 | -0.087 | ||
| CHIV0 | 0.990 | 0.076 | ||
| CHIV1 | 0.971 | 0.120 | ||
| CHIV2 | 0.913 | 0.137 | ||
| CHIV3P | 0.838 | 0.096 | ||
| CHIV3C | 0.476 | 0.148 | ||
| CHIV3CH | 0.016 | -0.088 | ||
| Wiener | Wiener topological index | 0.854 | 0.186 | |
| logZ | Logarithm of Hosoya topological index | -0.220 | -0.131 | |
| Zagreb | Zagreb topological index | 0.958 | 0.162 | |
*The first factor explains 52.8% of the variance and the second explains 12.7%. Factors with high loadings (>0.9 for first factors and >0.8 for second factors) are shown in bold.