|
| 1 | +""" |
| 2 | +Filtering GDB-13 |
| 3 | +Authors: Robert Pollice, Akshat Nigam |
| 4 | +Date: Sep. 2020 |
| 5 | +""" |
| 6 | + |
| 7 | +# SETTING UP PYTON ENVIRONMENT |
| 8 | +# Load modules |
| 9 | +import numpy as np |
| 10 | +import pandas as pd |
| 11 | +import rdkit as rd |
| 12 | +import rdkit.Chem as rdc |
| 13 | +import rdkit.Chem.Descriptors as rdcd |
| 14 | +import rdkit.Chem.rdMolDescriptors as rdcmd |
| 15 | +import rdkit.Chem.Lipinski as rdcl |
| 16 | +import rdkit.Chem.rdmolops as rdcmo |
| 17 | +import argparse as ap |
| 18 | +import pathlib as pl |
| 19 | +cwd = pl.Path.cwd() # define current working directory |
| 20 | + |
| 21 | +def smiles_to_mol(smiles): |
| 22 | + """ |
| 23 | + Convert SMILES to mol object using RDKit |
| 24 | + """ |
| 25 | + try: |
| 26 | + mol = rdc.MolFromSmiles(smiles) |
| 27 | + except: |
| 28 | + mol = None |
| 29 | + return mol |
| 30 | + |
| 31 | +def maximum_ring_size(mol): |
| 32 | + """ |
| 33 | + Calculate maximum ring size of molecule |
| 34 | + """ |
| 35 | + cycles = mol.GetRingInfo().AtomRings() |
| 36 | + if len(cycles) == 0: |
| 37 | + maximum_ring_size = 0 |
| 38 | + else: |
| 39 | + maximum_ring_size = max([len(ci) for ci in cycles]) |
| 40 | + return maximum_ring_size |
| 41 | + |
| 42 | +def minimum_ring_size(mol): |
| 43 | + """ |
| 44 | + Calculate minimum ring size of molecule |
| 45 | + """ |
| 46 | + cycles = mol.GetRingInfo().AtomRings() |
| 47 | + if len(cycles) == 0: |
| 48 | + minimum_ring_size = 0 |
| 49 | + else: |
| 50 | + minimum_ring_size = min([len(ci) for ci in cycles]) |
| 51 | + return minimum_ring_size |
| 52 | + |
| 53 | +def substructure_violations(mol): |
| 54 | + """ |
| 55 | + Check for substructure violates |
| 56 | + Return True: contains a substructure violation |
| 57 | + Return False: No substructure violation |
| 58 | + """ |
| 59 | + violation = False |
| 60 | + # filter used for GDB13 filtering |
| 61 | + forbidden_fragments = ['[Cl,Br,I]', '*=*=*', '*#*', '[O,o,S,s]~[O,o,S,s]', '[N,n,O,o,S,s]~[N,n,O,o,S,s]~[N,n,O,o,S,s]', '[C,c]~N=,:[O,o,S,s;!R]', '[N,n,O,o,S,s]~[N,n,O,o,S,s]~[C,c]=,:[O,o,S,s,N,n;!R]', '*=[NH]', '*=N-[*;!R]', '*~[N,n,O,o,S,s]-[N,n,O,o,S,s;!R]', '*-[CH1]-*', '*-[CH2]-*', '*-[CH3]'] |
| 62 | + |
| 63 | + for ni in range(len(forbidden_fragments)): |
| 64 | + |
| 65 | + if mol.HasSubstructMatch(rdc.MolFromSmarts(forbidden_fragments[ni])) == True: |
| 66 | + violation = True |
| 67 | + break |
| 68 | + else: |
| 69 | + continue |
| 70 | + |
| 71 | + return violation |
| 72 | + |
| 73 | +def aromaticity_degree(mol): |
| 74 | + """ |
| 75 | + Compute the percentage of non-hydrogen atoms in a molecule that are aromatic |
| 76 | + """ |
| 77 | + atoms = mol.GetAtoms() |
| 78 | + atom_number = rdcl.HeavyAtomCount(mol) |
| 79 | + aromaticity_count = 0. |
| 80 | + |
| 81 | + for ai in atoms: |
| 82 | + if ai.GetAtomicNum() != 1: |
| 83 | + if ai.GetIsAromatic() == True: |
| 84 | + aromaticity_count += 1. |
| 85 | + |
| 86 | + degree = aromaticity_count / atom_number |
| 87 | + |
| 88 | + return degree |
| 89 | + |
| 90 | +def conjugation_degree(mol): |
| 91 | + """ |
| 92 | + Compute the percentage of bonds between non-hydrogen atoms in a molecule that are conjugated |
| 93 | + """ |
| 94 | + bonds = mol.GetBonds() |
| 95 | + bond_number = 0. |
| 96 | + conjugation_count = 0. |
| 97 | + |
| 98 | + for bi in bonds: |
| 99 | + a1 = bi.GetBeginAtom() |
| 100 | + a2 = bi.GetEndAtom() |
| 101 | + if (a1.GetAtomicNum() != 1) and (a2.GetAtomicNum() != 1): |
| 102 | + bond_number += 1. |
| 103 | + if bi.GetIsConjugated() == True: |
| 104 | + conjugation_count += 1. |
| 105 | + |
| 106 | + degree = conjugation_count / bond_number |
| 107 | + |
| 108 | + return degree |
| 109 | + |
| 110 | +def main(): |
| 111 | + # parse arguments |
| 112 | + parser = ap.ArgumentParser() |
| 113 | + parser.add_argument('data', help="CSV file of SMILES. Delimiter should be space and it should have no header.", type=str) |
| 114 | + parser.add_argument('--removed', help="Wheter or not to save list of removed SMILES. '0', do not save, or '1', save. Default is '0'.", type=str, choices=['0', '1'], default='0') |
| 115 | + arguments = parser.parse_args() |
| 116 | + |
| 117 | + # Generate output name |
| 118 | + output = arguments.data.split('.') |
| 119 | + output[-2] += '_filtered' |
| 120 | + output = '.'.join(output) |
| 121 | + output_removed = arguments.data.split('.') |
| 122 | + output_removed[-2] += '_removed' |
| 123 | + output_removed = '.'.join(output_removed) |
| 124 | + |
| 125 | + # Load data |
| 126 | + data = pd.read_csv(arguments.data, delimiter=' ', usecols=[0, 1], names=['SMILES','NUMBER'], skiprows=0) |
| 127 | + print('Original Data: ' + str(len(data.index))) |
| 128 | + |
| 129 | + # Generate mol objects from smiles and remove compounds that returned erros |
| 130 | + data['MOL'] = data['SMILES'].apply(smiles_to_mol) |
| 131 | + new_data = data[data['MOL'] != None] |
| 132 | + data = new_data.copy() |
| 133 | + data['CSMILES'] = data['MOL'].apply(lambda x: rdc.MolToSmiles(x, isomericSmiles=False, canonical=True)) |
| 134 | + print('RDKit Converted: ' + str(len(data.index))) |
| 135 | + |
| 136 | + # Added after GDB-13 was filtered to get rid charged molecules |
| 137 | + data['CHARGE'] = data['MOL'].apply(lambda x: rdcmo.GetFormalCharge(x)) |
| 138 | + new_data = data[(data['CHARGE'] == 0)] |
| 139 | + data = new_data.copy() |
| 140 | + print('Filtered by molecular charge: ' + str(len(data.index))) |
| 141 | + |
| 142 | + # Added after GDB-13 was filtered to get rid radicals |
| 143 | + data['RADICALS'] = data['MOL'].apply(lambda x: rdcd.NumRadicalElectrons(x)) |
| 144 | + new_data = data[(data['RADICALS'] == 0)] |
| 145 | + data = new_data.copy() |
| 146 | + print('Filtered by number of radicals: ' + str(len(data.index))) |
| 147 | + |
| 148 | + # Filter by bridgehead atoms |
| 149 | + # Note: filters are ordered by increasing timing requirements |
| 150 | + data['BRIDGEHEAD'] = data['MOL'].apply(lambda x: rdcmd.CalcNumBridgeheadAtoms(x)) |
| 151 | + new_data = data[data['BRIDGEHEAD'] == 0] |
| 152 | + data = new_data.copy() |
| 153 | + print('Filtered by bridgehead atoms: ' + str(len(data.index))) |
| 154 | + |
| 155 | + # Filter by spiro atoms |
| 156 | + data['SPIROATOMS'] = data['MOL'].apply(lambda x: rdcmd.CalcNumSpiroAtoms(x)) |
| 157 | + new_data = data[data['SPIROATOMS'] == 0] |
| 158 | + data = new_data.copy() |
| 159 | + print('Filtered by spiro atoms: ' + str(len(data.index))) |
| 160 | + |
| 161 | + # Filter by aromaticity |
| 162 | + data['AROMATICITY'] = data['MOL'].apply(lambda x: aromaticity_degree(x)) |
| 163 | + new_data = data[data['AROMATICITY'] >= 0.50] |
| 164 | + data = new_data.copy() |
| 165 | + print('Filtered by aromaticity: ' + str(len(data.index))) |
| 166 | + |
| 167 | + # Filter by conjugation |
| 168 | + data['CONJUGATION'] = data['MOL'].apply(lambda x: conjugation_degree(x)) |
| 169 | + new_data = data[data['CONJUGATION'] >= 0.70] |
| 170 | + data = new_data.copy() |
| 171 | + print('Filtered by conjugation: ' + str(len(data.index))) |
| 172 | + |
| 173 | + # Filter by ring size |
| 174 | + data['MAXIMUM_RINGSIZE'] = data['MOL'].apply(lambda x: maximum_ring_size(x)) |
| 175 | + new_data = data[(data['MAXIMUM_RINGSIZE'] >= 5) & (data['MAXIMUM_RINGSIZE'] <= 7)] |
| 176 | + data = new_data.copy() |
| 177 | + print('Filtered by maximum ring size: ' + str(len(data.index))) |
| 178 | + |
| 179 | + # Added after GDB-13 was filtered to get rid of 3-membered rings |
| 180 | + data['MINIMUM_RINGSIZE'] = data['MOL'].apply(lambda x: minimum_ring_size(x)) |
| 181 | + new_data = data[(data['MINIMUM_RINGSIZE'] >= 5) & (data['MINIMUM_RINGSIZE'] <= 7)] |
| 182 | + data = new_data.copy() |
| 183 | + print('Filtered by minimum ring size: ' + str(len(data.index))) |
| 184 | + |
| 185 | + # Filter by functional groups |
| 186 | + data['VIOLATIONS'] = data['MOL'].apply(lambda x: substructure_violations(x)) |
| 187 | + new_data = data[data['VIOLATIONS'] == False] |
| 188 | + removed_data = data[data['VIOLATIONS'] == True] |
| 189 | + data = new_data.copy() |
| 190 | + print('Filtered by functional groups: ' + str(len(data.index))) |
| 191 | + |
| 192 | + # Save processed data |
| 193 | + data.to_csv(output, columns = ['SMILES','NUMBER'], sep = ' ', index = False, header = False) |
| 194 | + |
| 195 | + if arguments.removed == '1': |
| 196 | + removed_data.to_csv(output_removed, columns = ['SMILES','NUMBER'], sep = ' ', index = False, header = False) |
| 197 | + |
| 198 | + return |
| 199 | + |
| 200 | + |
| 201 | +if __name__ == "__main__": |
| 202 | + main() |
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