Chemistry Reference
In-Depth Information
O
O
NN
15.8
15.8
388.9
720.9
720.9
FIGURE 4.8
Aromaticity map of Black Indanthrone.
and high aromaticity (Figure 4.8). For Black
Indanthrone one calculates, for instance,
the following descriptors:
•
percentage of aromatic bonds 87.2%
•
average aromaticity of aromatic bonds 415.3
•
number of aromatic zones 5
•
variation coefficient of masses in aromatic zones 106%
•
average aromaticity of aromatic zones 372.4 ± 352.7
•
variation coefficient of aromaticity in aromatic zones 94.7%
•
length of LATP (Longest Aromatic Topological Path
)
22
•
aromaticity of LATP 395.4
4.3.16 3d d
escriptors
In order to calculate 3D descriptors, the analyzed molecule is placed into a regu-
lar, virtual, three-dimensional network of points. The 3D descriptors are basically
characteristics of some physical quantities, calculated in the points of the network.
The value of the 3D descriptors depends on the position in space of the considered
point and on the characteristics of the atoms in certain areas of the molecule. When
a group of molecules is analyzed, the network of points includes the package of
overlapped molecules. The methods used to overlap molecules are highly diverse.
For example, molecules can be overlapped on the common skeleton if present. Other
methods overlap the vectors of the dipole moments of the molecules in the package.
The value of the 3D descriptors is influenced by the method used to overlap the
molecules and by the distance between the network points. A different approach is
to use the molecules in the package in their position within the effector-active site
ensemble if such position can be determined.
