Patents can contain valuable chemical and biological information not found in scientific journals. This document discusses extracting key compounds from patents, including identifying sources for full-text patents, extracting compounds from text, and predicting key compounds through methods like frequency of group analysis. Predicting key compounds is important as they are often the most biologically active and suitable for further development. The document provides examples of extracting known drug compounds like Bextra, Aciphex, and Aricept from early patents through these methods.