A Retrieval System of Medicine Molecules Based on Graph Similarity

Medicine information retrieval has grown significantly and is based on structural similarity of medicine molecules. The chemical structural formula (CSF) is a primary search target as a unique identifier for each compound in the research field of medical information. This paper introduces a graph-based CSF retrieval system, PharmKi, which accepts the photos taken from smartphones and the sketches drawn on tablet PCs as inputs. To establish a compact yet efficient hypergraph representation for molecules, we propose a graph-isomorphism-based algorithm for evaluating the spatial similarity between graphical CSFs. An indexing strategy based on the graph TF-IDF technology is also introduced to achieve a high efficiency for large-scale molecule retrieval. The results of comparative study demonstrate that the proposed method outperforms the existing methods on accuracy, and performs well on efficiency.