Hollis Showalter joined the University of Michigan in 2006 after more than 25 years of drug discovery and development experience within the pharmaceutical industry.  He has broad experience in synthetic medicinal chemistry and has contributed to a number of campaigns resulting in agents proceeding to clinical trials.  One of these, Nipent™, is marketed for the treatment of hairy cell leukemia.  He was the founding Director of the University of Michigan Vahlteich Medicinal Chemistry Core (, which works with collaborators in hit-to-lead campaigns to advance their drug discovery efforts, contribute synthetic and medicinal chemistry strategies to grant proposals, and develop biological probes or potential therapeutic agents for biological investigation.  He also provides expertise on intellectual property protection.  He has published 173 peer reviewed manuscripts/reviews/book chapters, and 161 meeting abstracts.  He holds 47 issued or applied for patents. 

He has served professionally on numerous internal and external committees, including industry, UM, and the American Chemical Society Medicinal Chemistry Division. 

For a complete profile of Showalter’s professional history, refer to his CV.

Research Interests

  • Natural products modification and heterocyclic chemistry synthesis

  • Designing in physicochemical properties to high-throughput screen hits that confer “druggability” (e.g., conformity to Lipinski rules, absence of toxicophores)

  • Development of structure-activity relationships (SAR) to derive compounds with optimal pharmacokinetic and metabolic profiles toward the initiation of in vivo studies

  • Principal therapeutic focus in bacterial diseases and oncology with extensive knowledge of associated targets, e.g., RNA polymerase and protein kinases

Selected Publications

  • Showalter, HD.  Recent Progress in the Discovery and Development of 2-Nitroimidazooxazines and 6-Nitroimidazooxazoles to Treat Tuberculosis and Neglected Tropical Diseases. Molecules (Basel, Switzerland), 2020; 25: 4137.  PMID: 32927749. 

  • Liu X, Wilson MW, Liu K, Lee P, Yeomans L, Hagen SE, Lin C-M, Wen B, Sun D, White AD, Showalter HD, Antonetti DA.  Synthesis and Structure-activity Relationships of Thieno[2,3-d]pyrimidines as Atypical Protein Kinase C Inhibitors to Control Retinal Vascular Permeability and Cytokine-induced Edema.  Bioorg. Med. Chem., 2020, 28: article ID 115480.  PMID: 32327351.

  • Ashkar SR, Rajeswaran W, Lee PH, Yeomans L,Thrasher CM, Franzblau SG, Murakami KS, Showalter HD, Garcia GA.  Optimization of Benzoxazinorifamycins to Minimize hPXR Activation for Treatment of Tuberculosis and HIV Coinfection.  ACS Infect. Dis.,  2022, 8: 1408 - 1421.  PMID: 35772743.

  • Rajeswaran W, Ashkar SR, Lee PH, Yeomans L, Shin Y, Franzblau SG, Murakami KS, Showalter HD, Garcia GA.  Optimization of Benzoxazinorifamycins to Improve Mycobacterium tuberculosis RNA Polymerase Inhibition and Treatment of Tuberculosis.  ACS Infect. Dis., 2022, 8: 1422 – 1438. PMID: 35772744.