Automated de novo molecular design by hybrid machine intelligence and rule-driven chemical synthesis

Abstract

Chemical creativity in the design of new synthetic chemical entities (NCEs) with drug-like properties has been the domain of medicinal chemists. Here, we explore the capability of a chemistry-savvy machine intelligence to generate synthetically accessible molecules. DINGOS (design of innovative NCEs generated by optimization strategies) is a virtual assembly method that combines a rule-based approach with a machine learning model trained on successful synthetic routes described in chemical patent literature. This unique combination enables a balance between ligand-similarity-based generation of innovative compounds by scaffold hopping and the forward-synthetic feasibility of the designs. In a prospective proof-of-concept application, DINGOS successfully produced sets of de novo designs for four approved drugs that were in agreement with the desired structural and physicochemical properties. Target prediction indicated more than 50% of the designs to be biologically active. Four selected computer-generated compounds were successfully synthesized in accordance with the synthetic route proposed by DINGOS. The results of this study demonstrate the capability of machine learning models to capture implicit chemical knowledge from chemical reaction data and suggest feasible syntheses of new chemical matter.

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Fig. 1: Overview of the DINGOS software.
Fig. 2: Representation of the single-step molecule assembly procedure.
Fig. 3: Flow chart summarizing the ith iteration of the DINGOS algorithm.
Fig. 4: Distance comparison of the DINGOS, ChEMBL bioactive and construction sets.
Fig. 5: Selected de novo designs generated by DINGOS.

Data availability

The trained machine learning model, CAS numbers of the training data and reaction SMARTS used in this Article are provded in the Code Ocean capsule https://doi.org/10.24433/CO.6930970.v132. All molecules were preprocessed in accordance with the procedure stated in the Methods (see ‘Molecular building blocks’ section).

Code availability

The code for this Article, along with an accompanying computational environment, are available and executable online as a Code Ocean capsule: https://doi.org/10.24433/CO.6930970.v132.

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Acknowledgements

The authors thank L. Friedrich, C. Brunner, B. Huisman, X. Zhang and R. Byrne for stimulating discussions and technical support. D.M. was financially supported by an ETH Zurich Postdoctoral Fellowship (grant no. 16–2 FEL-07). This research was financially supported by the Swiss National Science Foundation (grant no. 205321_182176 to G.S.).

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Contributions

A.B. programmed the software and performed the computational experiments. A.B., J.A.H. and G.S. designed the algorithm and analysed the data. D.M. supervised the chemical part of the study and, together with A.B., synthesized the compounds. G.S. designed the study. All authors analysed the results and contributed to the manuscript.

Corresponding author

Correspondence to Gisbert Schneider.

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Competing interests

G.S. declares a potential conflict of interest in his role as life-science industry consultant and cofounder of inSili.com GmbH, Zurich. No other competing interests are declared.

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Button, A., Merk, D., Hiss, J.A. et al. Automated de novo molecular design by hybrid machine intelligence and rule-driven chemical synthesis. Nat Mach Intell 1, 307–315 (2019). https://doi.org/10.1038/s42256-019-0067-7

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