Reaction Searching Using Fingerprints-Based Approach

2 Reaction Searching Using Fingerprints-Based Approach 

In the previous chapter, we learnt the use of fingerprints for searching chemical structures. Of equal importance is the need for searching chemical reactions to estimate their similarity using computational tools. In this section, we will therefore learn how to use reaction fingerprints for searching in databases and online servers. Similar techniques are employed in both cases. Stractural properties that are present in the reaction are used for estimation of reaction similarity. Two reactions can be considered similar if their product side artd/or reactant side are similar. With this consideration, reaction sirrrilarity is reduced to molecular or 5irMctMro/ similarity. 

An alternative approaeh is to eharacterize the reaction transformation carried out by identifying the changing atoms arrd the changing bonds in the reaction with respect to the reactants arrd the produet stractirres. An atom is changing if either of the conditions is met  

One or more of its bond is ehanged (i.e., the bond is different on the left side compared to the right side) or 

It is preserrt only on one side of the reaction and it has a non-changing atom neighbor. 

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