The common practice of including tables of Markush representations (although they improve SAR readability), makes the extraction problem worse. While most medicinal chemistry journals will include IUPAC names in the synthesis descriptions, these also have to be pulled "back out" of the PDF. This can be done via PDF-to-text Optical Character Recognition (OCR) or curated by pasting across to the Open Parser for Systematic IUPAC Nomenclature (OPSIN) tool . Here again, both the automatic and manual procedures are error prone.