Re: [Open Babel] Combine two SMARTS patterns

[Andrew D. <da...@da...>]

On Mar 6, 2009, at 9:29 AM, Andreas Maunz wrote:
>> It's possible to enumerate all maximum common substructure
>> between the two SMARTS
> How can that be done?


"It's possible" means "with some non-trivial programming."

Here's a sketch of how to do it:
   - parse the SMARTS into a graph data structure

   - apply normalizations so that, for example, [#6] and [C,c] are  
the same
       (though you really only need to know if a node paring or
         edge pairing is valid, so it's not quite that complicated)
       (And if you control how the SMARTS are generated, then this
        step might not be needed.)

   - implement an MCS algorithm on those graphs

I don't think OpenBabel has code that can easily be adapted to
this. OEChem might, but it's a corner I don't know about. I
don't think RDKit nor CDK make it easy either.

				Andrew
				da...@da...