N-hexylsulfonyl indole based thiosemicarbazones as potent and selective ecto-5'-nucleotidase and NTPDase inhibitors

e5'NT (ecto-5'-nucleotidase) and NTPDases (nucleoside triphosphate diphosphohydrolase) belong to the family of ectonucleotidases. NTPDases play a critical role in regulating ATP levels by catalyzing the hydrolysis of ATP, while e5'NT works in conjunction with NTPDases to catabolize nucleotide molecules. Given their involvement in inflammation, infection, and cancer disorders, e5'NT and NTPDases are promising therapeutic targets. Herein, we have synthesized a series of sixteen N-substituted indole-based thiosemicarbazones 5(a-p) and investigated them for their potential inhibitory effect on the ectonucleotidases e5'NT and NTPDase1, -2, -3, and - 8. Several compounds presented outstanding inhibition potential against one or more forms with IC₅₀ values in the ranges as follows: 0.6 ± 2.1 to 2.2 ± 0.6 μM (h-ecto5'NT), 1.0 ± 0.03 to 3.6 ± 0.1 μM (NTPDase1), 1.3 ± 0.06 to 4.2 ± 0.04 μM (NTPDase2), 1.1 ± 1.2 to 4.2 ± 0.04 μM (NTPDase3), 1.5 ± 0.09 to 4.1 ± 0.1 μM (NTPDase8), respectively. Compounds 5 l and 5 m displayed selective inhibition against NTPDase1 and NTPDase2, respectively. Molecular docking and molecular dynamics (MD) simulation experiments were conducted to learn more about the nature of binding site interactions. The observed results provide compelling evidence for the potency of the indole scaffold as a powerful and selective inhibitor of NTPDases.