Fig. 4

An RG core that represents 302 compounds in P2X7. The nodes are represented by text labels that specify the node type and numerical indices which allow them to be identified uniquely. The text labels correspond to elements outside of those commonly seen in organic molecules, for example, “Ca” represents an aliphatic node with hydrogen bond acceptor character. The different node types and their labels are described later. The substructures represented by the node labelled “3No” are shown in Fig. 5