Flag issues, standardize, and visualize molecular structures with ease.

A collection of chemical filters, with some support for data visualization and analysis. Supported filters include:

• RDKit's structural alert filters* including BMS, Dundee, Glaxo, Inpharmatica, LINT, MLSMR, PAINS, and SureChEMBL FilterCatalogs;
• Purchasability filters based on molbloom;
• SMARTS-like Peptide filters as implemented in PepSift;
• Silly molecules filters as implemented in molspotter;

*Note: RDKit's implementation these chemical filters is only available from rdkit version 2023.03.1 onwards. Check here for the release notes.

Overview:

The different filtering classes are implemented with a similar API, where get_(flagging|scoring)_df run all the filters available for that class and return a dataframe with all the results. In case of the RdkitFilters implementation, a few visualization methods are available to render the molecules, substructure matches, and molecular grids.

See available filters and visualization methods below:

• chemFilters
  • Overview:
  • Installation
  • Documentation:
  • Filtering Compounds
    • RdkitFilters
    • Purchasability filters
    • Silly molecules filters
    • Peptide filters
    • Core filters
    • CLI
  • Visualization
    • Rendering a grid of molecules;
    • Rendering substructure matches:
    • Rendering substructure matches with colors:

Installation

The base package includes RDKit filters and visualization:

pip install chem-filters

Some features require additional dependencies, available as extras:

Extra	Includes	Required for
allfilters	pepsift, molspotter, molbloom	Peptide, silly molecule, and purchasability filters
standardizers	papyrus_structure_pipeline, molvs	Molecular standardization
full	All of the above	All features

# Install with all filters
pip install "chem-filters[allfilters]"

# Install everything
pip install "chem-filters[full]"

Alternatively, install directly from the GitHub repository:

pip install git+https://github.com/David-Araripe/chemFilters.git
pip install "chem-filters[full] @ git+https://github.com/David-Araripe/chemFilters.git"

Documentation

chemFilters' documentation is available on readthedocs (RTD) here!

Filtering Compounds

RdkitFilters

from chemFilters import RdkitFilters
from rdkit import Chem

mols = [
    Chem.MolFromSmiles("CCC1=[O+][Cu-3]2([O+]=C(CC)C1)[O+]=C(CC)CC(CC)=[O+]2"),
    Chem.MolFromSmiles("CC1=C2C(=COC(C)C2C)C(O)=C(C(=O)O)C1=O"),
    Chem.MolFromSmiles("CCOP(=O)(Nc1cccc(Cl)c1)OCC"),
    Chem.MolFromSmiles("Nc1ccc(C=Cc2ccc(N)cc2S(=O)(=O)O)c(S(=O)(=O)O)c1"),
]

rdkit_filter = RdkitFilters(filter_type='ALL', from_smi=False)
filtered_df = rdkit_filter.get_flagging_df(mols)

Purchasability filters

from chemFilters import MolbloomFilters
bloom_filter = MolbloomFilters(from_smi=False, standardize=False)
bloom_filter.get_flagging_df(mols)

Silly molecules filters

from chemFilters import SillyMolFilters
silly_filter = SillyMolFilters(from_smi=False)
silly_filter.get_scoring_df(mols)

Peptide filters

from chemFilters import PeptideFilters
pep_filter = PeptideFilters(from_smi=False)
pep_filter.get_flagging_df(mols)

Core filters

The package also has an implementation that allows applying all available filters at once. This implementation is also used in the CLI version of the package. For further configuration options, check the CLI help.

from chemFilters.core import CoreFilters

smiles = [
    "CCC1=[O+][Cu-3]2([O+]=C(CC)C1)[O+]=C(CC)CC(CC)=[O+]2",
    "CC1=C2C(=COC(C)C2C)C(O)=C(C(=O)O)C1=O",
    "CCOP(=O)(Nc1cccc(Cl)c1)OCC",
    "Nc1ccc(C=Cc2ccc(N)cc2S(=O)(=O)O)c(S(=O)(=O)O)c1",
]

core_filter = CoreFilters()
filtered_df = core_filter(smiles)

CLI

After installing the package, the CLI can be used to filter datasets. The CLI has the following options:

usage: chemFilters [-h] -i INPUT [-c COL_NAME] -o OUTPUT [--rdkit-filter] [--no-rdkit-filter]
                   [--rdkit-subset RDKIT_SUBSET] [--rdkit-valtype RDKIT_VALTYPE] [--pep-filter] [--no-pep-filter]
                   [--silly-filter] [--no-silly-filter] [--bloom-filter] [--no-bloom-filter] [--std-mols]
                   [--no-std-mols] [--std-method STD_METHOD] [--n-jobs N_JOBS] [--chunk-size CHUNK_SIZE]

Where --<name>-filter and --no-<name>-filter enables and disables the implemented filters. Same goes for the parameter --std-mols, that enables the molecular standardization according to --std-method.

Visualization

Rendering a grid of molecules;

from rdkit import Chem
from chemFilters.img_render import MolPlotter, MolGridPlotter

mols = [
    Chem.MolFromSmiles("CCC1=[O+][Cu-3]2([O+]=C(CC)C1)[O+]=C(CC)CC(CC)=[O+]2"),
    Chem.MolFromSmiles("CC1=C2C(=COC(C)C2C)C(O)=C(C(=O)O)C1=O"),
    Chem.MolFromSmiles("CCOP(=O)(Nc1cccc(Cl)c1)OCC"),
    Chem.MolFromSmiles("Nc1ccc(C=Cc2ccc(N)cc2S(=O)(=O)O)c(S(=O)(=O)O)c1"),
]
labels = [f"Molecule {i}" for i in range(1, len(mols) + 1)]

# Initialize grid plotter instance
grid_plotter = MolGridPlotter(from_smi=False, font_name="Telex-Regular")

img = grid_plotter.mol_grid_png(mols[:4], n_cols=2, labels=labels)
display(img)

Rendering substructure matches:

chemFilter = RdkitFilters(filter_type="ALL")
filter_names, description, substructs = chemFilter.filter_mols(mols)

grid_plotter = MolGridPlotter(
    from_smi=False, font_name="Telex-Regular", size=(250, 250)
)

img = grid_plotter.mol_structmatch_grid_png(mols, substructs=substructs, n_cols=2)
display(img)

Rendering substructure matches with colors:

from chemFilters import RdkitFilters
import matplotlib.pyplot as plt

chemFilter = RdkitFilters(filter_type="NIH")
filter_names, description, substructs = chemFilter.filter_mols(mols)

plotter = MolPlotter(
    from_smi=False, label_font_size=20, size=(350, 350), font_name="Telex-Regular"
)
img = plotter.render_with_colored_matches(
    mols[0],
    descriptions=description[0],
    substructs=substructs[0],
    label=labels[0],
    alpha=0.3,
)

plt.imshow(img)
ax = plt.gca()  # get current axis
ax.set_axis_off()
plotter.colored_matches_legend(description[0], substructs[0], ax=ax)
fig = plt.gcf()  # get current figure
fig.savefig(  # save matplotlib figure
    "figures/colored_matches.png", bbox_inches="tight", dpi=150, facecolor="white"
)