Analysis of 40 years’ worth of patents reveals pharma reaction trends

A massive computer-guided text mining of pharmaceutical industry patents has helped elucidate what kinds of reactions have been run most often by medicinal chemists over the past 40 years.

Previous efforts to dissect the “medicinal chemist’s toolbox” in this way have focused mainly on parsing selected sets of research journals or data from company electronic lab notebooks. For the new study, lead author Nadine Schneider of the Novartis Institutes for BioMedical Research and her colleagues considered that far more medicinal chemistry is revealed in patents.

The Novartis team, working with researchers from NextMove Software, a company developing chemistry informatics tools, turned up 1.3 million unique chemical reactions along with molecule data from 200,000 U.S. patents issued from 1976 to 2015. They report their analysis highlights in a research paper in the Journal of Medicinal Chemistry (2016, DOI: 10.1021/acs.jmed​chem.6b00153) and include complete data in the paper’s supporting information and supplemental interactive online graphics.

The team’s sprawl of information reveals the waxing and waning of chemists’ bread-and-butter reactions as the research landscape has evolved with new strategies and new classes of drugs. For example, Suzuki-Miyaura couplings have moved to the fore, and although some classics such as Wittig olefinations have declined as a result, others such as the Grignard reaction have held steady. Overall, the findings show an increase in the number of reaction types and a trend toward lower product yield. They also show that today’s molecules are larger, have more aromatic rings, are more hydrophobic, and are more rigid than those from 40 years ago.