Chemistry Cartridge: TAUTOMERS

Daylight 4.61, dayblob 46107, Oracle Server 8.13

The Chemistry Cartridge adds the TAUTOMERS operator to SQL. When applied to a SMILES-containing column in a table, all rows containing possible tautomers of a given SMILES will be selected. For this purpose, structures are considered tautomers if they have same molecular graph, molecular formula (including hydrogen count) and net charge. I.e., they can be changed into one another by moving only electrons and hydrogen atoms. This is a fast search which is done by indexed (hashed) retrieval. Other examples are also available.
Oracle table: COMPOUND_118616 (nci95 structures)
Look for the following structure:


O=C1CN(N=Cc2ccc(o2)N(=O)=O)C(=O)N1

SQLPLUS session follows (show .sql file):


TO_CHAR(SYSDATE,'MM:
--------------------
10:21:1998, 05:32:26

Elapsed: 00:00:00.00
old   1: select compound_id, smiles from COMPOUND_118616 where Tautomers(smiles,'&1')=1
new   1: select compound_id, smiles from COMPOUND_118616 where Tautomers(smiles,'O=C1CN(N=Cc2ccc(o2)N(=O)=O)C(=O)N1')=1

     ID SMILES
------- --------------------------------------
  78432 [O-][N+](=O)c1ccc(C=NN2CC(=O)NC2=O)o1

Elapsed: 00:00:00.69

TO_CHAR(SYSDATE,'MM:
--------------------
10:21:1998, 05:32:27


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