This calculates the number of aromatic rings in a compound. This has been proposed by Ritchie and Macdonald as a characteristic that is inidcative of the developability of a compound (Ritchie and Macdonald (2009), Drug Discov. Today 14 pp. 1011-1020). They suggest that greater than three aromatic rings increases correlates with poorer compound developability and an increased risk of attrition in development.

When installed, this will appear in StarDrop in the “Models” tab alongside the ADME QSAR models and other simple properties as a “Custom model”, allowing it to be calculated easily for any data set. If you’ve not used custom models before, details on how to install it are available on the following pages, along with the model file…

Installation

Save the model file (Number of aromatic rings.aim) into a directory of your choice.
To access the model quickly you can simply right-click on the Models tab in StarDrop, choose Open Model… and then open the saved file.
To ensure StarDrop always has this model available, open the Preferences (File->Preferences) and, in the File Locations tab, add the directory where the model was saved into the Models section.