(448c) Accfg: Accurate Functional Group Extraction and Molecular Structure Comparison

Functional groups are specific molecular patterns that influence a molecule's chemical and physical properties. Identifying them is crucial for understanding the structure-activity relationships. Currently, accurately extracting functional groups from complex molecular structures remains a challenge. In this work, we present AccFG, a tool designed for precise functional group extraction and molecular structure comparison (Fig. 1). Based on a predefined functional group library to construct a hierarchical structure for functional groups, AccFG addresses the redundancy and incompleteness issues of existing methods. Additionally, AccFG's output includes identified functional groups and heterocycles with their corresponding mapped atom numbers, which enables molecular structure comparisons at the functional group level with alkane difference (difference in carbon backbone). We evaluated its performance on various datasets and examples with manual examination. The results demonstrate the superior accuracy and precision of AccFG when handling complex molecules and function groups. We anticipate that AccFG will serve as a useful tool for processing functional groups, and its comprehensive, structured output enables fine-grained insights between molecular structures and properties.

Figure 1. Examples of AccFG in (a) functional group extraction and (b) molecule comparison. AccFG provides accurate, readable, and interoperable results on both of the tasks compared with EFG¹ and Ertl’s method².

References

1. Salmina, Elena S., Norbert Haider, and Igor V. Tetko. "Extended functional groups (EFG): an efficient set for chemical characterization and structure-activity relationship studies of chemical compounds." Molecules1 (2015): 1.
2. Colmenarejo, Gonzalo. "EFGs: A Complete and Accurate Implementation of Ertl’s Functional Group Detection Algorithm in RDKit." Journal of Chemical Information and Modeling 65.3 (2025): 1061-1066.