Changes in Dragon 5.5 blocks |

The Dragon 5.5 block n.2 Topological descriptors was renamed as Topological indices and was divided into six sub-blocks:
A few descriptors of the old block n. 2 Topological descriptors were moved elsewhere and, in almost all the cases, with a different label:
The block n. 3 Walk and path counts was divided into five different sub-blocks:
These can be now calculated as integer numbers or by applying the transformation logarithmic (i.e., ln(1 + x)) depending on the specific setting chosen by the user. Dragon default is application of logarithmic transformation.
The block n. 4 Connectivity indices was divided into four sub-blocks and now includes a new set of molecular descriptors:
The block n. 5 Information indices was divided into two sub-blocks:
The block n. 6 2D autocorrelations was divided into five sub-blocks and now includes a new set of molecular descriptors:
The block n. 7 Edge adjacency indices was largely extended by introduction of indices from unsymmetrical weighted edge adjacency matrices in addition to indices from augmented edge adjacency matrices. Moreover, a basic set of spectral indices is now calculated from all the defined edge matrices. This block was divided into four sub-blocks:
The block n. 8 Burden eigenvalues was extended by also including eigenvalues from Burden matrix based on ionization potential and topological intrinsic state as the atom weighting scheme. It was divided into two sub-blocks:
The block n. 9 Topological charge indices no longer exists. It is now a sub-block of the block 2D Autocorrelations with the novel name Topological charge autocorrelations.
The block n. 10 Eigenvalue-based indices no longer exists. It was largely extended by application of basic spectral operators to a number of graph-theoretical matrices. The eigenvalue-based indices of Dragon 5.5 are now located in the block 2D matrix-based descriptors, most of them with a different label. The correspondence between Dragon 5.5 eigenvalue-based indices and those of Dragon 6.0 is reported below.
Dragon 5.5 eigenvalue-based indices in Dragon 6.0.
The block n. 11 Randic molecular profile was divided into two sub-blocks:
The block n. 12 Geometrical descriptors was divided into four sub-blocks:
Some of the indices originally included in this block are now located in the novel block of 3D Matrix-based descriptors, with a different label. They are listed in the table below. Moreover, the set of substructure descriptors, which are defined as the sum of geometrical distances between pairs of atom types, are now located in the novel block of 3D Atom Pairs, with the name Weighted geometrical atom pairs
Dragon 5.5 geometrical descriptors that were placed in other blocks of Dragon 6.0.
The block n. 13 RDF descriptors was extended from 150 to 210 indices and the block n. 14 3D-MoRSE descriptors from 160 to 224 indices, including also indices calculated on the basis of ionization potential and topological intrinsic state as the atom weighting scheme. These blocks were also divided into a number of sub-blocks according to the atom weighting scheme used for their calculation:
In the block n. 15 WHIM descriptors, all the indices derived from the electrotopological state (s) as the atom weighting scheme were replaced with those calculated from the topological I-state (s) and indices based on the first ionization potential were added (i). This block was also divided into two sub-blocks:
The block n. 16 GETAWAY descriptors was enlarged from 197 to 273 by introduction of the indices calculated from the ionization potential and the topological I-state as the atom weighting scheme. This block was also divided into three sub-blocks:
In the block n. 18 Atom-centred fragments five undefined molecular descriptors were deleted from the list.
The block n. 20 Molecular properties now includes some new molecular descriptors related to the total molecular volume and surface area of donor and acceptor atoms, a novel index of unsaturation and the packing density index. Moreover, some indices were moved to the novel block of Drug-like indices. These are listed below.
Dragon 5.5 descriptors of the block Molecular properties moved to the block Drug-like indices in Dragon 6.0.
The blocks n. 21 2D Binary fingerprints and n. 22 2D Frequency fingerprints no longer exist, they being now the sub-blocks Binary Atom Pairs and Frequency Atom Pairs, respectively, into the novel block 2D Atom Pairs. |