Isotope Searching ?

Hello

I am running the following queries using the cartridge.

 

Query 1 - I get one hit with 18O isotope

 

select * from evo_compound_form
where jc_compare(smiles, '[18O]=Cc1ccccc1', 't:e') = 1

 

Query 2 - I get 9 records, and this includes the hit from the first query, as expected

 

select * from evo_compound_form
where jc_compare(smiles, 'O=Cc1ccccc1', 't:e') = 1

 

Query 3 - I get no hits, I would have expected to see all the hits from Query 2 minus the hits from Query 1

 

select * from evo_compound_form
where jc_compare(smiles, '[16O]=Cc1ccccc1', 't:e') = 1

 

Thanks

Catherine

PS - Below are the details on our jchem environment

 

Oracle environment:
Oracle Database 10g Release 10.2.0.4.0 - 64bit Production
PL/SQL Release 10.2.0.4.0 - Production
CORE    10.2.0.4.0    Production
TNS for Linux: Version 10.2.0.4.0 - Production
NLSRTL Version 10.2.0.4.0 - Production

 

JChem Server environment:
Java VM vendor: Sun Microsystems Inc.
Java version: 1.6.0_11
Java VM version: 11.0-b16
JChem version: 5.2.6
JChem Index version: 5020400
JDBC driver version: 11.1.0.7.0-Production

 

 

 

Hi Catherine,

On the target side, an oxygen without isotopic specification is meant to be in a natural abundance of isotopes, whereas [16O] would refer to a pure sample of isotope 16 only.

On the other hand, at the query side, a nonisotopic query means to retrieve all isotopic forms by default, and a specific isotopic label retrieves that particular isotope only, never the natural abundance.

However, you could use the exact isotope option with a nonisotopic query to obtain the behaviour that you want. ("isotope:e" search option)

 

Please note that this will modify isotope matching at all atoms.

More details about this option and isotope matching in general:

http://www.chemaxon.com/jchem/doc/user/query_features.html#iso_charge_rad

 

Best regards,

Szabolcs

Thanks for the very useful and quick answer

Catherine