I did need to add hydrogens for it work correctly, since the exocyclic
hydrogens needed to be there to be wedged/dashed, however I used these two
lines to ensure I only added the ones I needed:
On Thu, Oct 19, 2017 at 2:41 PM, Chris Murphy <chris.mur...@schrodinger.com>
wrote:
> Greg,
>
> That did the trick, thanks so much for the help!
>
> On Wed, Oct 18, 2017 at 2:13 AM, Greg Landrum <greg.land...@gmail.com>
> wrote:
>
>>
>>
>> On Tue, Oct 17, 2017 at 8:16 PM, Chris Murphy <
>> chris.mur...@schrodinger.com> wrote:
>>
>>>
>>> I am trying to implement a function that cleans up chiral centers by
>>> moving the wedged/dashed stereo bond out of a ring and onto a function
>>> group or hydrogen if possible.
>>>
>>
>> As a general thing: the existing function Chem.WedgeMolBonds() should
>> already handle assigning wedged bonds to exocyclic atoms. It does not,
>> however, remove existing wedging. I think that this is probably what you
>> should be using, but for that to be useful you first need to have a
>> molecule with atomic stereochemistry assigned and wedging info removed from
>> bonds.
>>
>> If you skip sanitization when processing a mol block (which is what I
>> suspect based on your previous messages), you end up with a molecule that
>> has the atomic stereochemistry assigned, but with the wedging information
>> still there. Removing the existing wedging info and then calling
>> Chem.WedgeMolBonds() should get you what you're looking for.
>>
>> The function to remove bond wedging isn't currently exposed to Python, I
>> can do that, but in the meantime a python translation isn't complicated:
>>
>> In [42]: def ClearSingleBondDirFlags(m):
>> ...: for bond in m.GetBonds():
>> ...: if bond.GetBondType() == Chem.BondType.SINGLE:
>> ...: if bond.GetBondDir() == Chem.BondDir.UNKNOWN:
>> ...: bond.SetProp("_UnknownStereo",1)
>> ...: bond.SetBondDir(Chem.BondDir.NONE)
>>
>> The piece with the _UnknownStereo property is important to make sure info
>> about wavy (I call them "squiggle") bonds is maintained.
>>
>> If the combination of this function and Chem.WedgeMolBonds() isn't enough
>> to solve the problem, I'll get into the rest of your question, but I
>> think/hope that this might do it and save you some time and effort.
>>
>> P.S. If anyone could offer a good suggestion for how to determine if the
>>> bond I am moving the dash/wedge to should be dashed or wedged that would
>>> also be super helpful.
>>>
>>
>> That's a non-trivial bit of C++ code that isn't currently exposed to the
>> python interface. I don't think it would be hard to do that if it would be
>> helpful.
>>
>> -greg
>>
>>
>>
>>
>>> I have been able to successfully identify the wedged bonds and the
>>> adjacent bond to move the wedge/dash stereo bond to and move the stereo
>>> bond off of the ring bond, but when I check the result, I notice that I
>>> assigned the wrong wedge/dash form to one of the bonds, so I want to check
>>> the chirality of the atoms after doing my changes and flip the ones that
>>> are wrong.
>>>
>>> However, I am noticing that the output of Chem.FindMolChiralCenters(mol)
>>> does not change (as well as atom.GetProp('_CIPCode')), even if I change all
>>> of the bonds to either dashed or wedged, or another combination that should
>>> clearly change the original chirality of the stereocenters. I tried
>>> calling rdmolops.AssignStereochemistry(mol), but the result of
>>> FindMolChiralCenters and atom.GetProp('_CIPCode') still does not change.
>>>
>>
>>> Does SetBondDir actually affect the R/S chiral tags on the atoms? Is
>>> there a good way to check if the changes in the bonds have changed the
>>> chirality at a given chiral center?
>>>
>>>
>>>
>>
>
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