def run_reactants(self, rxnSmarts, reactantSmiles,
needsExplicitHs=False, needsEnvironments=True):
"""Return a list of unique reaction products.
Function is a wrapper around the RDKit built-in RunReaction() which attempts to
address its limitations related to handling stereochemistry in reaction cores.
"""
# By default, rewrite the transform using SMARTS environments.
logging.debug("processing run_reactants")
if needsEnvironments:
logging.debug('environment needed: compacting: '+ rxnSmarts)
rxnSmarts = compact(rxnSmarts)
logging.debug('environmental compacting done: '+ rxnSmarts)
# Generate reaction from input SMARTS.
try:
logging.debug('trying rdkit reaction from smarts with ' + rxnSmarts)
rxn = AllChem.ReactionFromSmarts(rxnSmarts)
rxn.Initialize()
except:
logging.error('invalid SMARTS: {0}'.format(rxnSmarts))
self.out.append('Error: invalid SMARTS: {0}.\n'.format(rxnSmarts))
sys.exit(1)
# Convert reactants SMILES to molecules and add explicit H atoms need if
# requested.
logging.debug('reaction initialized')
reactants = [Chem.MolFromSmiles(s) for s in reactantSmiles.split('.')]
if needsExplicitHs:
reactants = [self.add_Hs(m) for m in reactants]
if None not in reactants:
[m.UpdatePropertyCache() for m in reactants]
else:
self.out.append('Error: invalid input SMILES.\n')
sys.exit(1)
# Number atoms in reactants.
self.number_atoms(reactants)
# Create reactant atom map.
reactantAtomMap = self.create_reactant_map(reactants)
# Run reaction transform.
try:
productList = rxn.RunReactants(tuple(reactants))
except:
self.out.append('Error: Applying transform failed.\n')
sys.exit(1)
# Create template atom maps.
[rTemplateList, pTemplateList, rTemplateAtomMaps, pTemplateAtomMaps, IsMatchChiral] = self.create_template_map(reactants, rxn)
if len(IsMatchChiral) != len(productList):
self.out.append('Error: Template maps does not match products.\n')
sys.exit(1)
# Remove non-chiral matches AND check for ring-opening reactions.
newProductList = []
for idx, products in enumerate(productList):
if IsMatchChiral[idx]:
newProducts = list(products)
possibleOverlaps = True
while possibleOverlaps:
[possibleOverlaps, newProducts] = self.merge(newProducts)
newProductList.append(tuple(newProducts))
productList = tuple(newProductList)
# Parse products to correct chirality.
for matchIdx, products in enumerate(productList):
for product in products:
for productAtom in product.GetAtoms():
if not productAtom.HasProp('Core'):
# Unique atom ID
atomIdx = productAtom.GetIsotope()
# Map Atoms
tmp = reactantAtomMap[atomIdx] if atomIdx in reactantAtomMap.keys() else None
reactantAtom = reactants[tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
tmp = rTemplateAtomMaps[matchIdx][atomIdx] if atomIdx in rTemplateAtomMaps[matchIdx].keys() else None
rTemplateAtom = rTemplateList[matchIdx][tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
tmp = pTemplateAtomMaps[matchIdx][atomIdx] if atomIdx in pTemplateAtomMaps[matchIdx].keys() else None
pTemplateAtom = pTemplateList[matchIdx][tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
# Correct Chirality of Product Atom
self.fix_chirality(reactantAtom, productAtom, rTemplateAtom, pTemplateAtom)
# Remove Hs if necessary
if needsExplicitHs:
tempProductList = []
for products in productList:
tempProductList.append([self.remove_Hs(p) for p in products])
productList = tempProductList
# Remove atom mappings.
for products in productList:
for product in products:
for atom in product.GetAtoms():
atom.SetIsotope(0)
atom.ClearProp('Core')
# Get unique product sets.
uniqueProductSets = []
for products in productList:
uniqueProductSets.append('.'.join(set([Chem.MolToSmiles(p, isomericSmiles=True) for p in products])))
return self.uniquify(uniqueProductSets)
def run_reactants(rxnSmarts, reactantSmiles,
needsExplicitHs=False, needsEnvironments=True,
needsStereoTunneling=True,
error=None):
"""Return a list of unique reaction products.
Function is a wrapper around the RDKit built-in RunReaction() which attempts to
address its limitations related to handling stereochemistry in reaction cores.
"""
if error == None : error=logging.getLogger("stereotest.stereofix").error
# By default, rewrite the transform using SMARTS environments.
if needsEnvironments:
rxnSmarts = compact(rxnSmarts)
# Generate reaction from input SMARTS.
try:
rxn = AllChem.ReactionFromSmarts(rxnSmarts)
rxn.Initialize()
except:
error('Invalid SMARTS: {0}.'.format(rxnSmarts))
return None
# Convert reactants SMILES to molecules and add explicit H atoms need if
# requested.
reactants = [Chem.MolFromSmiles(s) for s in reactantSmiles.split('.')]
if needsExplicitHs:
reactants = [add_Hs(m) for m in reactants]
if None not in reactants:
[m.UpdatePropertyCache() for m in reactants]
else:
error('Invalid SMILES among reactants.')
return None
# Number atoms in reactants.
number_atoms(reactants)
# Create reactant and product atom maps.
reactantAtomMap = create_atom_map(reactants)
# Temporarily remove chiral centers from the reactants.
if needsStereoTunneling:
backup = copy.deepcopy(reactants)
for reactant in reactants:
for rAtom in reactant.GetAtoms():
if rAtom.GetChiralTag() != ChiralType.CHI_UNSPECIFIED:
rAtom.SetChiralTag(ChiralType.CHI_UNSPECIFIED)
# Run reaction transform.
try:
productList = rxn.RunReactants(tuple(reactants))
except:
error('Applying transform failed.')
return None
# Restore chiral centers to reactants and introduce them in relevant atoms
# of products.
if needsStereoTunneling:
reactants = backup
for products in productList:
for product in products:
for pAtom in product.GetAtoms():
if pAtom.GetIsotope() not in reactantAtomMap.keys():
continue
rIdx, rAtomIdx = reactantAtomMap[pAtom.GetIsotope()]
rAtom = reactants[rIdx].GetAtomWithIdx(rAtomIdx)
if rAtom.GetChiralTag() != pAtom.GetChiralTag():
copy_chirality(rAtom, pAtom)
# Create template atom maps.
[rTemplateList, pTemplateList, rTemplateAtomMaps, pTemplateAtomMaps, IsMatchChiral] = create_template_map(reactants, rxn)
if len(IsMatchChiral) != len(productList):
error('Template maps does not match products.')
return None
# Remove non-chiral matches AND check for ring-opening reactions.
newProductList = []
rTemplateListIdx = 0
for idx, products in enumerate(productList):
if IsMatchChiral[idx]:
newProducts = list(products)
while True:
[mergeIdx, newProducts] = merge(newProducts)
if mergeIdx < 0:
break
# Fix bonds
#
# Note:
# It is probably an overkill, but I am not sure at the moment
# how to pass relevant reactant and reactant template in case
# of multi reactants reaction. Thus, using a brute force
# approach, I iterate over all of them.
for newProductIdx in range(len(newProducts)):
for reactant, rTemplate in zip(reactants, rTemplateList[rTemplateListIdx]):
newProducts[newProductIdx] = fix_bonds(reactant, rTemplate, newProducts[newProductIdx])
newProductList.append(tuple(newProducts))
rTemplateListIdx += 1
productList = tuple(newProductList)
# Parse products to correct chirality.
for matchIdx, products in enumerate(productList):
for product in products:
for productAtom in product.GetAtoms():
if not productAtom.HasProp('Core'):
# Unique atom ID
atomIdx = productAtom.GetIsotope()
# Map Atoms
tmp = reactantAtomMap[atomIdx] if atomIdx in reactantAtomMap.keys() else None
reactantAtom = reactants[tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
tmp = rTemplateAtomMaps[matchIdx][atomIdx] if atomIdx in rTemplateAtomMaps[matchIdx].keys() else None
rTemplateAtom = rTemplateList[matchIdx][tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
tmp = pTemplateAtomMaps[matchIdx][atomIdx] if atomIdx in pTemplateAtomMaps[matchIdx].keys() else None
pTemplateAtom = pTemplateList[matchIdx][tmp[0]].GetAtomWithIdx(tmp[1]) if tmp is not None else None
# Correct Chirality and charge of Product Atom
fix_chirality(reactantAtom, productAtom, rTemplateAtom, pTemplateAtom)
fix_charge(reactantAtom, productAtom, rTemplateAtom, pTemplateAtom)
# Remove Hs if necessary
if needsExplicitHs:
tempProductList = []
for products in productList:
mols = [remove_Hs(p) for p in products]
if None in mols:
return None
tempProductList.append(mols)
productList = tempProductList
# Remove atom mappings.
for products in productList:
for product in products:
for atom in product.GetAtoms():
atom.SetIsotope(0)
atom.ClearProp('Core')
# Get unique product sets.
uniqueProductSets = []
for products in productList:
uniqueProductSets.append('.'.join([Chem.MolToSmiles(p, isomericSmiles=True) for p in products]))
uniqueProductsList = uniquify(uniqueProductSets)
# Convert to molecules.
productList = []
for s in uniqueProductsList:
products = [Chem.MolFromSmiles(smi) for smi in s.split('.')]
productList.append(products)
# Get transpose matrix of the productList.
newProductList = map(list, zip(*productList))
# Merge product list if any isomers are present.
finalProducts = []
needsMerging = False
for products in newProductList:
if are_isomers(products):
needsMerging = True
break
needsMerging = False
if needsMerging:
for products in newProductList:
mi = products[0]
for mj in products:
mi = combine_stereoisomers(mi, mj)
if mi is None:
return None
finalProducts.append(Chem.MolToSmiles(mi, isomericSmiles=True))
finalProductSets = ['.'.join(finalProducts)]
else:
finalProductSets = uniqueProductsList
return finalProductSets
