Dragon 6 is an application for the calculation of molecular descriptors. These descriptors can be used to evaluate molecular structure-activity or structure-property relationships, as well as for similarity analysis and high-throughput screening of molecule databases. Dragon 6 calculates 4885 molecular descriptors (see the complete descriptor list). In this latest version of Dragon, new molecular descriptors have been added, such as CATS 2D, Klein TDB autocorrelations, atom-type E-state indices, ETA descriptors, P_VSA descriptors, ring descriptors, several indices from different 2D and 3D matrices, drug-like and lead-like filters. Dragon 6 has been reconceived with the aim of proposing an even more powerful application for descriptor calculation and analysis. Dragon 6 has been designed to work both for Windows and Linux, as graphical and command-line interface. The changes between Dragon 5.5 and Dragon 6.0 are listed in the on-line help. The Graphical User Interface has been completely renewed to improve and facilitate selection and calculation of molecular descriptors. Moreover, new tools for the screening analysis of calculated descriptors have been added.

Look at the screenshots of Dragon 6.

Dragon 6 main features

The complete list of Dragon features is available in the on-line Dragon user manual.

Input files. Together with the molecule formats allowed in the previous versions of Dragon (MDL, Sybyl, HyperChem, Macromodel and Smiles), new formats are now supported: CML (Chemical Markup Language) and HyperChem format as a unique file. There are no restrictions on the number of molecules and on the atom types. The novel Dragon graphical interface for molecule import is very flexible allowing also selection of structures that are stored by different file formats and located in different folders. Molecular structures stored in files of different types can be loaded and contemporarily processed in the same batch.

Graphics and statistics. Graphical tools are available in Dragon 6 for a preliminary descriptor analysis. These graphs allow a preliminary analysis of molecule distribution in the descriptor space, as well as a preliminary correlation analysis. Look at the screenshots of Dragon 6.

A molecule viewer is provided to display the molecular structures that have been imported for descriptor calculation.

Loading of user-defined variables. Dragon allows the user to import up to 200 variables and string fields that can be added to the calculated molecular descriptors such as experimental properties and information on the processed molecules (e.g., CAS number, product code).