2. Academic Validation
  3. Revisiting tubercidin against kinetoplastid parasites: Aromatic substitutions at position 7 improve activity and reduce toxicity

Revisiting tubercidin against kinetoplastid parasites: Aromatic substitutions at position 7 improve activity and reduce toxicity

  • Eur J Med Chem. 2019 Feb 15:164:689-705. doi: 10.1016/j.ejmech.2018.12.050.
Fabian Hulpia 1,  Gustavo Daniel Campagnaro 2,  Mirko Scortichini 3,  Kristof Van Hecke 4,  Louis Maes 5,  Harry P de Koning 2,  Guy Caljon 5,  Serge Van Calenbergh 6
Affiliations

Affiliations

  • 1 Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium.
  • 2 Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom.
  • 3 School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032, Camerino, Italy.
  • 4 XStruct, Department of Chemistry, Ghent University, Krijgslaan 281 (S3), B-9000, Gent, Belgium.
  • 5 Laboratory of Microbiology, Parasitology and Hygiene, University of Antwerp, Universiteitsplein 1 (S7), B-2610, Wilrijk, Belgium.
  • 6 Laboratory for Medicinal Chemistry (Campus Heymans), Ghent University, Ottergemsesteenweg 460, B-9000, Gent, Belgium. Electronic address: serge.vancalenbergh@ugent.be.
PMID: 30677668 DOI: 10.1016/j.ejmech.2018.12.050
Abstract

The nucleoside Antibiotic tubercidin displays strong activity against different target organisms, but it is notoriously toxic to mammalian cells. The effects of tubercidin against T. brucei parasites inspired us to synthesize several C7 substituted analogs for in vitro evaluation in order to find suitable hit compounds. C7 Deazaadenosines substituted with electron-poor phenyl groups were found to have micromolar activity against T. brucei in vitro. Replacement of the phenyl for a pyridine ring gave compound 13, with submicromolar potency and much-attenuated cytotoxicity compared to tubercidin. The veterinary pathogen T. congolense was equally affected by 13in vitro. Transporter studies in T. b. brucei indicated that 13 is taken up efficiently by both the P1 and P2 adenosine transporters, making the occurrence of transporter-related resistance and cross-resistance with diamidine drugs such as diminazene aceturate and pentamidine as well as with melaminophenyl arsenicals unlikely. Evaluation of the in vitro metabolic stability of analog 13 indicated that this analog was significantly metabolized in mouse microsomal fractions, precluding further in vivo evaluation in mouse models of HAT.

Keywords

7-Deazapurine nucleosides; Negishi cross coupling; Trypanosoma brucei brucei; Trypanosoma cruzi.

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