Duplicate search for enhanced stereo specification

User cdc1fd6fff

26-06-2014 07:16:30

hi, we got two isomers but we didn't make sure the exact stereo chemistry. if we input one isomer like attached image into database, we don't know how to input another one into database due to duplicate setting.


Could you recommend a way to describe this situation? or can we modify the duplicate setting to let both two isomers into database


Thanks for help

ChemAxon abe887c64e

26-06-2014 09:51:56

Hi,


Sorry, I'm not sure I correctly understand your question. You would like to import two structures into a database table ( the table has 'filter out duplicate structures' setting), these two structures are drawn as enantiomers of each other,  one of them drawn with 'single up' bond while the other drawn with 'single down' bond, and there is the 'or1' enhanced stereo label on the stereocenters?  See attached picture.


Our duplicate search evaluates these two structures as duplicates because both drawing represent 'itself or its enantiomer' according to the 'or1' label.


If you want to store both of them into a table with 'filter out duplicate structures' settings you would have remove the 'or1' label.


If you cannot modify the structures, then switching off duplicate filtering could help to import both structures.


Krisztina

User cdc1fd6fff

27-06-2014 03:22:11

hi, Krisztina,


You understanding is correct. 


If we remove the "or1" label, the structure will be misunderstood as exact structure, but we are not sure which is R or S. however, we can't switch off the duplicate filtering due to huge repeated structure


So we are wondering if we can modify the duplicate filtering to accept both unsure stereo structures. or there is another way to describe these unsure structures. we have another special case: there were two chiral atoms in one structure. we got cis mixture and trans mixture, but we don't know which is cis or trans. How to input two mixture into database?


Thank you

ChemAxon abe887c64e

30-06-2014 09:44:35

 


Also, you would like to import two structures - when the duplicate filtering options is switched on - which differ in ... what?


I can only imagine the following two structures which are not regarded as duplicates of each other. See attached:


Unfortunately, the search options of the duplicate search  - which runs
during the duplicate filtering process of the database import  - cannot be
modified, it uses the default duplicate search settings (exact charge,
exact isotope, exact stereo, ...).


My other idea would be to change your workflow, first run duplicate search with customized search option settings, when you could use attached data to differentiate your structures. In that case, the import would run without duplicate filtering.


Best regards,


Krisztina


 


 

User cdc1fd6fff

07-07-2014 01:59:36

Thanks for your suggestion. We will try the method of adding attached data