N6-modification of 7-Deazapurine nucleoside analogues as Anti-Trypanosoma cruzi and anti-Leishmania agents: Structure-activity relationship exploration and In vivo evaluation

Chagas disease and leishmaniasis are two poverty-related neglected tropical diseases that cause high mortality and morbidity. Current treatments suffer from severe limitations and novel, safer and more effective drugs are urgently needed. Both Trypanosoma cruzi and Leishmania are auxotrophic for purines and absolutely depend on uptake and assimilation of host purines. This led us to successfully explore purine nucleoside analogues as chemotherapeutic agents against these and other kinetoplastid in-fections. This study extensively explored the modification of the 6-amino group of tubercidin, a natural product with trypanocidal activity but unacceptable toxicity for clinical use. We found that mono-substitution of the amine with short alkyls elicits potent and selective antitrypanosomal and anti-leishmanial activity. The methyl analogue 15 displayed the best in vitro activity against both T. cruzi and L. infantum and high selectivity versus host cells. Oral administration for five consecutive days in an acute Chagas disease mouse model resulted in significantly reduced peak parasitemia levels (75, 89 and 96% with 12.5, 25 and 50 mg/kg/day, respectively). as well as increased animal survival rates with the lower doses (83 and 67% for 12.5 and 25 mg/kg/day, respectively). (c) 2022 Elsevier Masson SAS. All rights reserved.

Automated summary

Chagas disease and leishmaniasis are poverty-related neglected tropical diseases that require safer and more effective drugs. This study explored purine nucleoside analogues as chemotherapeutic agents against Trypanosoma cruzi and Leishmania infections. The methyl analogue showed the best activity against both parasites and high selectivity against host cells. Oral administration reduced parasitemia levels and increased animal survival rates in a mouse model.