Optimization of piperazine-derived ureas privileged structures for effective antiadenovirus agents

In recent years, human adenovirus (HAdV) infections have shown a high clinical impact in both immunosuppressed and immunocompetent patients. The research into specific antiviral drugs for the treatment of HAdV infections in immunocompromised patients constitutes a principal objective for medicinal chemistry due to the lack of any specific secure drug to treat these infections. In this study, we report a small-molecule library (67 compounds) designed from an optimization process of piperazine-derived urea privileged structures and their biological evaluation: antiviral activity and cytotoxicity. The active compounds selected were further evaluated to gain mechanistic understanding for their inhibition. Twelve derivatives were identified that inhibited HAdV infections at nanomolar and low micromolar concentrations (IC50 from 0.6 to 5.1 μM) with low cytotoxicity. In addition, our mechanistic assays suggested differences in the way the derivatives exert their anti-HAdV activity targeting transcription, DNA replication and later steps in the HAdV replication cycle. Furthermore, eight of the 12 studied derivatives blocked human cytomegalovirus (HCMV) DNA replication at low micromolar concentrations. The data provided herein indicates that the 12 thiourea/urea piperazine derivatives studied may represent potential lead compounds for clinical evaluation and development of new anti-HAdV drugs.
This work has been supported by Ministerio de Economía y Competitividad, Plan Estatal 2013–2016 Retos-Proyectos I + D + i (CTQ2016-78580-C2-2-R) and by Instituto de Salud Carlos III, Subdirección General de Redes y Centros de Investigación Cooperativa, Ministerio de Ciencia, Innovación y Universidades, Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0009) – co-financed by European Development Regional Fund “A way to achieve Europe”, Operative program Intelligent Growth 2014–2020, the Instituto de Salud Carlos III(DTS17/00130) and the Spanish Adenovirus Network (AdenoNet, BIO2015/68990-REDT) grants. MVH also thanks Ministerio de Economía y Competitividad, Plan Estatal 2013–2016 Excelencia I + D + i (CTQ2016-78703-P). JSC is a researcher belonging to the program “Nicolás Monardes” (C-0059-2018), Servicio Andaluz de Salud, Junta de Andalucía, Spain. FA thanks Dipartimento di Farmacia e Scienze della Salute e della Nutrizione-Dipartimento di Eccellenza MIUR L 232/2016". JAV thanks Junta de Andalucia (Contrato de Garantías Juveniles).