Package rdkit :: Package Chem :: Module BRICS
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Module BRICS

source code

Implementation of the BRICS algorithm from Degen et al. ChemMedChem *3* 1503-7 (2008)

Functions [hide private]
 
FindBRICSBonds(mol, randomizeOrder=False, silent=True)
returns the bonds in a molecule that BRICS would cleave
source code
 
BreakBRICSBonds(mol, bonds=None, sanitize=True, silent=True)
breaks the BRICS bonds in a molecule and returns the results
source code
 
BRICSDecompose(mol, allNodes=None, minFragmentSize=1, onlyUseReactions=None, silent=True, keepNonLeafNodes=False, singlePass=False, returnMols=False)
returns the BRICS decomposition for a molecule
source code
 
BRICSBuild(fragments, onlyCompleteMols=True, seeds=None, uniquify=True, scrambleReagents=True, maxDepth=3) source code
 
_test() source code
Variables [hide private]
  environs = {'L1': '[C;D3]([#0,#6,#7,#8])(=O)', 'L3': '[O;D2]-;...
  reactionDefs = [('1', '3', '-'), ('1', '5', '-'), ('1', '10', ...
  smartsGps = copy.deepcopy(reactionDefs)
  environMatchers = {}
  bondMatchers = []
  reactions = tuple([[Reactions.ReactionFromSmarts(y) for y in x...
  reverseReactions = []
  dummyPattern = Chem.MolFromSmiles('[*]')

Imports: sys, re, Chem, Reactions, iteritems, iterkeys, next, range, copy, random


Function Details [hide private]

FindBRICSBonds(mol, randomizeOrder=False, silent=True)

source code 
returns the bonds in a molecule that BRICS would cleave

>>> from rdkit import Chem
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> res = list(FindBRICSBonds(m))
>>> res
[((3, 2), ('3', '4')), ((3, 4), ('3', '4'))]

a more complicated case:
>>> m = Chem.MolFromSmiles('CCCOCCC(=O)c1ccccc1')
>>> res = list(FindBRICSBonds(m))
>>> res
[((3, 2), ('3', '4')), ((3, 4), ('3', '4')), ((6, 8), ('6', '16'))]

we can also randomize the order of the results:
>>> random.seed(23)
>>> res = list(FindBRICSBonds(m,randomizeOrder=True))
>>> sorted(res)
[((3, 2), ('3', '4')), ((3, 4), ('3', '4')), ((6, 8), ('6', '16'))]

Note that this is a generator function :
>>> res = FindBRICSBonds(m)
>>> res
<generator object ...>
>>> next(res)
((3, 2), ('3', '4'))

>>> m = Chem.MolFromSmiles('CC=CC')
>>> res = list(FindBRICSBonds(m))
>>> sorted(res)
[((1, 2), ('7', '7'))]

make sure we don't match ring bonds:
>>> m = Chem.MolFromSmiles('O=C1NCCC1')
>>> list(FindBRICSBonds(m))
[]

another nice one, make sure environment 8 doesn't match something connected
to a ring atom:
>>> m = Chem.MolFromSmiles('CC1(C)CCCCC1')
>>> list(FindBRICSBonds(m))
[]

BreakBRICSBonds(mol, bonds=None, sanitize=True, silent=True)

source code 
breaks the BRICS bonds in a molecule and returns the results

>>> from rdkit import Chem
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> m2=BreakBRICSBonds(m)
>>> Chem.MolToSmiles(m2,True)
'[3*]O[3*].[4*]CC.[4*]CCC'

a more complicated case:
>>> m = Chem.MolFromSmiles('CCCOCCC(=O)c1ccccc1')
>>> m2=BreakBRICSBonds(m)
>>> Chem.MolToSmiles(m2,True)
'[16*]c1ccccc1.[3*]O[3*].[4*]CCC.[4*]CCC([6*])=O'


can also specify a limited set of bonds to work with:
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> m2 = BreakBRICSBonds(m,[((3, 2), ('3', '4'))])
>>> Chem.MolToSmiles(m2,True)
'[3*]OCC.[4*]CCC'

this can be used as an alternate approach for doing a BRICS decomposition by
following BreakBRICSBonds with a call to Chem.GetMolFrags:
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> m2=BreakBRICSBonds(m)
>>> frags = Chem.GetMolFrags(m2,asMols=True)
>>> [Chem.MolToSmiles(x,True) for x in frags]
['[4*]CCC', '[3*]O[3*]', '[4*]CC']

BRICSDecompose(mol, allNodes=None, minFragmentSize=1, onlyUseReactions=None, silent=True, keepNonLeafNodes=False, singlePass=False, returnMols=False)

source code 
returns the BRICS decomposition for a molecule

>>> from rdkit import Chem
>>> m = Chem.MolFromSmiles('CCCOCc1cc(c2ncccc2)ccc1')
>>> res = list(BRICSDecompose(m))
>>> sorted(res)
['[14*]c1ccccn1', '[16*]c1cccc([16*])c1', '[3*]O[3*]', '[4*]CCC', '[4*]C[8*]']

>>> res = list(BRICSDecompose(m,returnMols=True))
>>> res[0]
<rdkit.Chem.rdchem.Mol object ...>
>>> smis = [Chem.MolToSmiles(x,True) for x in res]
>>> sorted(smis)
['[14*]c1ccccn1', '[16*]c1cccc([16*])c1', '[3*]O[3*]', '[4*]CCC', '[4*]C[8*]']

nexavar, an example from the paper (corrected):
>>> m = Chem.MolFromSmiles('CNC(=O)C1=NC=CC(OC2=CC=C(NC(=O)NC3=CC(=C(Cl)C=C3)C(F)(F)F)C=C2)=C1')
>>> res = list(BRICSDecompose(m))
>>> sorted(res)
['[1*]C([1*])=O', '[1*]C([6*])=O', '[14*]c1cc([16*])ccn1', '[16*]c1ccc(Cl)c([16*])c1', '[16*]c1ccc([16*])cc1', '[3*]O[3*]', '[5*]NC', '[5*]N[5*]', '[8*]C(F)(F)F']

it's also possible to keep pieces that haven't been fully decomposed:
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> res = list(BRICSDecompose(m,keepNonLeafNodes=True))
>>> sorted(res)
['CCCOCC', '[3*]OCC', '[3*]OCCC', '[3*]O[3*]', '[4*]CC', '[4*]CCC']

>>> m = Chem.MolFromSmiles('CCCOCc1cc(c2ncccc2)ccc1')
>>> res = list(BRICSDecompose(m,keepNonLeafNodes=True))
>>> sorted(res)
['CCCOCc1cccc(-c2ccccn2)c1', '[14*]c1ccccn1', '[16*]c1cccc(-c2ccccn2)c1', '[16*]c1cccc(COCCC)c1', '[16*]c1cccc([16*])c1', '[3*]OCCC', '[3*]OC[8*]', '[3*]OCc1cccc(-c2ccccn2)c1', '[3*]OCc1cccc([16*])c1', '[3*]O[3*]', '[4*]CCC', '[4*]C[8*]', '[4*]Cc1cccc(-c2ccccn2)c1', '[4*]Cc1cccc([16*])c1', '[8*]COCCC']

or to only do a single pass of decomposition:
>>> m = Chem.MolFromSmiles('CCCOCc1cc(c2ncccc2)ccc1')
>>> res = list(BRICSDecompose(m,singlePass=True))
>>> sorted(res)
['CCCOCc1cccc(-c2ccccn2)c1', '[14*]c1ccccn1', '[16*]c1cccc(-c2ccccn2)c1', '[16*]c1cccc(COCCC)c1', '[3*]OCCC', '[3*]OCc1cccc(-c2ccccn2)c1', '[4*]CCC', '[4*]Cc1cccc(-c2ccccn2)c1', '[8*]COCCC']

setting a minimum size for the fragments:
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> res = list(BRICSDecompose(m,keepNonLeafNodes=True,minFragmentSize=2))
>>> sorted(res)
['CCCOCC', '[3*]OCC', '[3*]OCCC', '[4*]CC', '[4*]CCC']
>>> m = Chem.MolFromSmiles('CCCOCC')
>>> res = list(BRICSDecompose(m,keepNonLeafNodes=True,minFragmentSize=3))
>>> sorted(res)
['CCCOCC', '[3*]OCC', '[4*]CCC']
>>> res = list(BRICSDecompose(m,minFragmentSize=2))
>>> sorted(res)
['[3*]OCC', '[3*]OCCC', '[4*]CC', '[4*]CCC']


Variables Details [hide private]

environs

Value:
{'L1': '[C;D3]([#0,#6,#7,#8])(=O)', 'L3': '[O;D2]-;!@[#0,#6,#1]', 'L4'\
: '[C;!D1;!$(C=*)]-;!@[#6]', 'L5': '[N;!D1;!$(N=*);!$(N-[!#6;!#16;!#0;\
!#1]);!$([N;R]@[C;R]=O)]', 'L6': '[C;D3;!R](=O)-;!@[#0,#6,#7,#8]', 'L7\
a': '[C;D2,D3]-[#6]', 'L7b': '[C;D2,D3]-[#6]', '#L8': '[C;!R;!D1]-;!@[\
#6]', 'L8': '[C;!R;!D1;!$(C!-*)]', 'L9': '[n;+0;$(n(:[c,n,o,s]):[c,n,o\
,s])]', 'L10': '[N;R;$(N(@C(=O))@[C,N,O,S])]', 'L11': '[S;D2](-;!@[#0,\
#6])', 'L12': '[S;D4]([#6,#0])(=O)(=O)', 'L13': '[C;$(C(-;@[C,N,O,S])-\
;@[N,O,S])]', 'L14': '[c;$(c(:[c,n,o,s]):[n,o,s])]', 'L14b': '[c;$(c(:\
...

reactionDefs

Value:
[('1', '3', '-'), ('1', '5', '-'), ('1', '10', '-'),], [('3', '4', '-'\
), ('3', '13', '-'), ('3', '14', '-'), ('3', '15', '-'), ('3', '16', '\
-'),], [('4', '5', '-'), ('4', '11', '-'),], [('5', '12', '-'), ('5', \
'14', '-'), ('5', '16', '-'), ('5', '13', '-'), ('5', '15', '-'),], [(\
'6', '13', '-'), ('6', '14', '-'), ('6', '15', '-'), ('6', '16', '-'),\
], [('7a', '7b', '='),], [('8', '9', '-'), ('8', '10', '-'), ('8', '13\
', '-'), ('8', '14', '-'), ('8', '15', '-'), ('8', '16', '-'),], [('9'\
, '13', '-'), ('9', '14', '-'), ('9', '15', '-'), ('9', '16', '-'),], \
...

reactions

Value:
tuple([[Reactions.ReactionFromSmarts(y) for y in x] for x in smartsGps\
])