What is medicinal chemistry? Delmis Hernandez, PhD candidate in the Department of Chemistry at Purdue University, describes the process of studying the skeletal structure of compounds to develop new medicines to fight cancer. Medicinal chemists identify the parts of a compound that are most effective as a medicine, but watch out for PAINS! These compounds give false positive results that seem promising as a drug when really the compounds might be toxic to both cancerous and healthy cells.