license: cc-by-nc-sa-4.0
tags:
- chemistry
- drug-design
- synthesis-accessibility
- cheminformatics
- drug-discovery
- selfies
- drugs
- molecules
- compounds
- ranger21
- madgrad
pipeline_tag: text-classification
Model Card for ChemFIE-SA (Synthesis Accessibility)
This model is a BERT-like sequence classifier for predicting synthesis accessibility given a SELFIES string of a compound, fine-tuned from gbyuvd/chemselfies-base-bertmlm on a DeepSA expanded train dataset (Wang et al. 2023).
Disclaimer: For Academic Purposes Only
The information and model provided is for academic purposes only. It is intended for educational and research use, and should not be used for any commercial or legal purposes. The author do not guarantee the accuracy, completeness, or reliability of the information.
Model Details
Model Description
- Model Type: Transformer (BertForSequenceClassification)
- Base model: gbyuvd/chemselfies-base-bertmlm
- Maximum Sequence Length: 512 tokens
- Number of Labels: 2 classes (0 ES: easy synthesis; 1 HS: hard to synthesize)
- Training Dataset: SELFIES with labels derived from DeepSA
- Language: SELFIES
- License: CC-BY-NC-SA 4.0
Uses
If you have Canonical SMILES instead of SELFIES, you can convert it first into a format readable by the model's tokenizer (using whitespace)
import selfies as sf
def smiles_to_selfies_sentence(smiles):
try:
selfies = sf.encoder(smiles) # Encode SMILES into SELFIES
selfies_tokens = list(sf.split_selfies(selfies))
# Join dots with the nearest next tokens
joined_tokens = []
i = 0
while i < len(selfies_tokens):
if selfies_tokens[i] == '.' and i + 1 < len(selfies_tokens):
joined_tokens.append(f".{selfies_tokens[i+1]}")
i += 2
else:
joined_tokens.append(selfies_tokens[i])
i += 1
selfies_sentence = ' '.join(joined_tokens)
return selfies_sentence
except sf.EncoderError as e:
print(f"Encoder Error: {e}")
return None
# Example usage:
in_smi = "C1CCC(CC1)(CC(=O)O)CN" # Gabapentin (CID3446)
selfies_sentence = smiles_to_selfies_sentence(in_smi)
print(selfies_sentence)
"""
[C] [C] [C] [C] [Branch1] [Branch1] [C] [C] [Ring1] [=Branch1] [Branch1] [#Branch1] [C] [C] [=Branch1] [C] [=O] [O] [C] [N]
"""
Direct Use using Classifier Pipeline
You can also use pipeline:
from transformers import pipeline
classifier = pipeline("text-classification", model="gbyuvd/synthaccess-chemselfies")
classifier("[C] [C] [C] [C] [Branch1] [Branch1] [C] [C] [Ring1] [=Branch1] [Branch1] [#Branch1] [C] [C] [=Branch1] [C] [=O] [O] [C] [N]") # Gabapentin
# [{'label': 'Easy', 'score': 0.9187200665473938}]
Training Details
Training Data
Data Sources
Training data is fetched from DeepSA's repository.
Data Preparation
- SMILES is converted into SELFIES
- Chunked into three parts to accommodate Paperspace's Gradient 6hrs limit.
- Then the data was split by 90:10 ratio of train:validation.
- 1st chunk size: 1,197,683 (1,077,915 train : 119,768 validation)
- The data contain labels for:
- 0: Easy synthesis (requires less than 10 steps)
- 1: Hard synthesis (requires more than 10 steps)
Training Procedure
Training Hyperparameters
- Epoch = 1 for each chunk
- Batch size = 128
- Number of steps for each chunk: 8422 I am using Ranger21 with these configuration:
Ranger21 optimizer ready with following settings:
Core optimizer = [madgrad](https://arxiv.org/abs/2101.11075)
Learning rate of 5e-06
Important - num_epochs of training = ** 1 epochs **
using AdaBelief for variance computation
Warm-up: linear warmup, over 2000 iterations
Lookahead active, merging every 5 steps, with blend factor of 0.5
Norm Loss active, factor = 0.0001
Stable weight decay of 0.01
Gradient Centralization = On
Adaptive Gradient Clipping = True
clipping value of 0.01
steps for clipping = 0.001
1st Chunk:
Step | Training Loss | Validation Loss | Accuracy | Precision | Recall | F1 | Roc Auc |
---|---|---|---|---|---|---|---|
8420 | 0.128700 | 0.128632 | 0.922860 | 0.975201 | 0.867836 | 0.918391 | 0.990007 |
Model Evaluation
Testing Data
The model (currently only trained on the 1st chunk) was evaluated using three distinct test sets provided by DeepSA's authors (Wang et al. 2023) to ensure comprehensive performance assessment across various scenarios:
Main Expanded Test Set
Independent Test Set 1 (TS1)
- Characteristics: Contains ES and HS compounds with high intra-group fingerprint similarity, but significant inter-group pattern differences.
Independent Test Set 2 (TS2)
- Characteristics: Contains a small portion of ES and HS molecules showing similar fingerprint patterns.
Independent Test Set 3 (TS3)
- Characteristics: All compounds exhibit high fingerprint similarity, presenting the most challenging classification task.
Evaluation Metrics
We employed a comprehensive set of metrics to evaluate our model's performance:
- Accuracy (ACC): Overall correctness of predictions
- Recall: Ability to identify all relevant instances (sensitivity)
- Precision: Accuracy of positive predictions
- F1-score: Harmonic mean of precision and recall
- Area Under the Receiver Operating Characteristic curve (AUROC): Model's ability to distinguish between classes
All metrics were evaluated using a threshold of 0.50 for binary classification.
Results
Below are the detailed results of our model's performance across all test sets:
Expanded Test Set Results
Comparison data is sourced from Wang et al. (2023), used various models as encoding layer:
- bert-mini (MinBert)
- bert-tini (TinBert)
- roberta-base (RoBERTa)
- deberta-v3-base (DeBERTa)
- Chem_GraphCodeBert (GraphCodeBert)
- electra-small-discriminator (SmELECTRA)
- ChemBERTa-77M-MTR (ChemMTR)
- ChemBERTa-77M-MLM (ChemMLM)
which was trained/fine-tuned to predict based on SMILES - while ChemFIE-SA is SELFIES-based:
Model | Recall | Precision | F–score | AUROC |
---|---|---|---|---|
DeepSA_DeBERTa | 0.873 | 0.920 | 0.896 | 0.959 |
DeepSA_GraphCodeBert | 0.931 | 0.944 | 0.937 | 0.987 |
DeepSA_MinBert | 0.933 | 0.945 | 0.939 | 0.988 |
DeepSA_RoBERTa | 0.940 | 0.940 | 0.940 | 0.988 |
DeepSA_TinBert | 0.937 | 0.947 | 0.942 | 0.990 |
DeepSA_SmELECTRA | 0.938 | 0.949 | 0.943 | 0.990 |
ChemFIE-SA | 0.952 | 0.942 | 0.947 | 0.990 |
DeepSA_ChemMLM | 0.955 | 0.967 | 0.961 | 0.995 |
DeepSA_ChemMTR | 0.968 | 0.974 | 0.971 | 0.997 |
TS1-3 Results
Comparison with DeepSA_SmELECTRA as described in Wang et al. (2023):
Datasets | Model | ACC | Recall | Precision | F-score | AUROC | Threshold |
---|---|---|---|---|---|---|---|
TS1 | DeepSA | 0.995 | 1.000 | 0.990 | 0.995 | 1.000 | 0.500 |
ChemFIE-SA | 0.996 | 1.000 | 0.992 | 0.996 | 1.000 | 0.500 | |
TS2 | DeepSA | 0.838 | 0.730 | 0.871 | 0.795 | 0.913 | 0.500 |
ChemFIE-SA | 0.805 | 0.775 | 0.770 | 0.773 | 0.886 | 0.500 | |
TS3 | DeepSA | 0.817 | 0.753 | 0.864 | 0.805 | 0.896 | 0.500 |
ChemFIE-SA | 0.731 | 0.642 | 0.781 | 0.705 | 0.797 | 0.500 |
Model Examination
You can visualize its attention heads using BertViz and attribution weights using Captum - as done in the base model in Interpretability section.
Compute Infrastructure
Hardware
- Platform: Paperspace's Gradients
- Compute: Free-P5000 (16 GB GPU, 30 GB RAM, 8 vCPU)
Software
- Python: 3.9.13
- Transformers: 4.42.4
- PyTorch: 2.3.1+cu121
- Accelerate: 0.32.0
- Datasets: 2.20.0
- Tokenizers: 0.19.1
- Ranger21: 0.0.1
- Selfies: 2.1.2
- RDKit: 2024.3.3
Citation
If you find this project useful in your research and wish to cite it, please use the following BibTex entry:
@software{chemfie_basebertmlm,
author = {GP Bayu},
title = {{ChemFIE Base}: Pretraining A Lightweight BERT-like model on Molecular SELFIES},
url = {https://huggingface.co/gbyuvd/chemselfies-base-bertmlm},
version = {1.0},
year = {2024},
}
References
@article{Wang2023DeepSA,
title={DeepSA: a deep-learning driven predictor of compound synthesis accessibility},
author={Wang, Shihang and Wang, Lin and Li, Fenglei and Bai, Fang},
journal={Journal of Cheminformatics},
volume={15},
pages={103},
year={2023},
month={Nov},
publisher={BioMed Central},
doi={10.1186/s13321-023-00771-3},
}
@article{krenn2020selfies,
title={Self-referencing embedded strings (SELFIES): A 100\% robust molecular string representation},
author={Krenn, Mario and H{\"a}se, Florian and Nigam, AkshatKumar and Friederich, Pascal and Aspuru-Guzik, Alan},
journal={Machine Learning: Science and Technology},
volume={1},
number={4},
pages={045024},
year={2020},
doi={10.1088/2632-2153/aba947}
}
@article{wright2021ranger21,
title={Ranger21: a synergistic deep learning optimizer},
author={Wright, Less and Demeure, Nestor},
year={2021},
journal={arXiv preprint arXiv:2106.13731},
}
Contact & Support My Work
G Bayu ([email protected])
This project has been quiet a journey for me, I’ve dedicated hours on this and I would like to improve myself, this model, and future projects. However, financial and computational constraints can be challenging.
If you find my work valuable and would like to support my journey, please consider supporting me here. Your support will help me cover costs for computational resources, data acquisition, and further development of this project. Any amount, big or small, is greatly appreciated and will enable me to continue learning and explore more.
Thank you for checking out this model, I am more than happy to receive any feedback, so that I can improve myself and the future model/projects I will be working on.