TABLE 1.

Description of the criteria used for the investigation of the use cases of literature-based drug discovery (LBD) listed in Supplementary Table S1 (see Supplementary Material).

Criteria	Details
Discoveries	The discoveries mentioned in the LDB use cases are expressed as hypothetical relationships between two or more concepts. Discoveries with identical semantic types of starting and target concepts reported in the same publication were pooled together
Starting and target concepts	The starting concept (A term in the ABC model) and the target concept (C term) of the discoveries are elucidated and classed into semantic categories (e.g., disease, substance (incl. drug), gene, and protein) based on information in the respective study or by using the resources listed below. In many cases (e.g., closed discoveries), starting and target concepts cannot be distinguished. Therefore, this categorisation follows a conceptual perspective with the principal aim of understanding the semantic types of the concepts involved in the discoveries
Discovery pattern	The principle discovery pattern followed in the study is described, whenever possible, as ABC relationship of the related concepts (A = starting concept, B = intermediate concept, C = target concept). The concepts are classed into semantic categories based on information in the respective study or by using the resources listed below
Natural products	The presence of natural products among the concepts involved in the discoveries is investigated. Concepts are assigned to one of the following natural product categories: N=Natural product from plants, microorganisms, and higher fungi, including secondary metabolites and small molecules as well as complex mixtures such as herbal substances or extracts; ND = Natural product derivative (derivatives of the above group of natural products including semi-synthetic compounds); A = Animal venom; M = Mineral; V=Vitamin. The resources used for the classification of the concepts are listed below
Major repository	Details about the major literature resource used for establishing the knowledge database linked with the respective discovery
Underlying method	Principle approach of the method used or, if appropriate, the name of the respective LBD system
Core interest	The core interest of the LBD approach as mentioned in the respective study
LBD category	The core LBD methodology used in the respective study either as Co-occurrence, Semantic, or Graph-base

Resources used for the classification of the concepts mentioned in the discoveries: PubChem (PubChem, 2020), Medical subject headings (MESH, 2020), and ChemIDplus (ChemIDplus, 2020) of the United States National Library of Medicine; RÖMPP, online, Lexicon of pharmaceuticals and natural products (Böckler et al., 2020); Newman’s and Cragg’s 2020 review on natural products as sources for new drugs (Newman and Cragg, 2020); Patridge’s 2016 analysis of FDA, approved natural product-related drugs (Patridge et al., 2016).