Fig. 5

a An example of a reaction paragraph where the product information in the reaction paragraph was recalled from the header. b OPSIN failed to convert the highlighted IUPAC name (in yellow) to a SMILES string. c Use of compound references in the reaction paragraph. d Missing brackets in the IUPAC, leading to OPSIN error when converting IUPAC to SMILES format. e Example of a reaction paragraph where some of the chemical entity information needs to be extracted from previous reaction paragraphs