R-group structures

Introduction

An R-group structure describes a set of derivatives in one structure (substitution variation). It is useful to define Markush-structures.

Definitions

• R-atom: A special type of atom that connects to a base molecule as ligand and abbreviates one or more possible structures. As there can be more than one R-atom in the same structure, they can be marked with R1, R2, R3, etc.

• **Root molecule or scaffold: ** The molecule to which the R-atoms connects. Note the R-atoms are part of of the root molecule as well.

• **R-group defintion: ** Lists of ligands that R-atoms abbreviate.

• **R-group: ** The whole structure described above. That is the root molecule and the R-group definition.