MACCS SGroups

We have therefore introduced the notion of an SGroup as an extension to chemical structure representation, and have implemented SGroups in a MACCS-II... 

The definition of a data SGroup (set of atoms and bonds) can be either tied directly to a chemical SGroup, or to an arbitrary set of atoms and bonds (except that once a bond is included, the two atoms of which it is composed are automatically included). Each data SGroup has associated with it a field and a value of data. The data fields to be allowed are defined by a database administrator as a part of the data dictionary. In the MACCS-II implementation, the program allows the same data field control as for data attached to the structure (text, numeric, and formatted). 

In MACCS-II this representation is in the form of a Molfile. Extensions have been added to the Molfile description that allow SGroup information to be stored and transferred to other programs. 

Besides having a graphical user interface, MACCS-II also provides access to structures through MEDIT, a structure editor which is available from the command line or from a MACCS-II program. The MEDIT language has been extended to allow for the definition, identification, modification, and deletion of SGroups. 

A new side menu for drawing and manipulating structures with SGroups has been added to the MACCS-II structure drawing editor (see Figure 12). 

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