Matched Molecular Reactants

What happens when you cross Matched Molecular Pair Analysis (MMPA) with reactions? Why, of course, you get a new paradigm in drug discovery, Matched Molecular Reactants!

Well, let’s think about it for a second. If you take the reactants and the products and look for matched molecular pairs combining both, what you will find are reactions that involve single R group transformations. We can call these Matched Molecular Reactants, but they are probably more commonly known as functional group transformations, e.g. -OH to -Cl.

So, what are the most common functional group transformations in a typical ELN? Well, I can’t show you that but I can show you the results when this analysis is applied to reactions in the US patent literature (this data courtesy of Daniel). The following table show SMILES for the R group together with the observed frequency for the 15 most common transformations:

*[N+](=O)[O-] --> *N                                    21456
*C --> *[H]                                             21165
*[H] --> *C                                             15583
*CC --> *[H]                                            12914
*C(=O)OC --> *C(=O)O                                    11729
*C(=O)OC(C)(C)C --> *[H]                                 9149
*NC(=O)OC(C)(C)C --> *N                                  8054
*C(=O)OCC --> *C(=O)O                                    7673
*Cc1ccccc1 --> *[H]                                      6695
*OC --> *O                                               6339
*[H] --> *Br                                             6141
*O --> *Cl                                               4852
*OCc1ccccc1 --> *O                                       4662
*[H] --> *CC                                             3980
*C(=O)O --> *C(=O)OC                                     3888

It seems that the majority of reactions tend to make molecules smaller. If this keeps up, we’ll soon be left with nothing!

HazELNut presented at Sheffield conference

Roger presented a talk entitled Extraction, Analysis, Atom Mapping, Classification and Naming of Reactions from Pharmaceutical ELNs at the recent 6th Joint Sheffield Conference on Chemoinformatics. This shows some of the problems encountered when handling data from pharamaceutical ELNs.

For more information on HazELNut see its webpage.