Design, synthesis, and high-throughput in vitro anti-cancer evaluation of novel 4-aminopyrazolo[3,4- d]pyrimidine derivatives: potential anti-cancer candidates against UO-31 renal cancer cells

Abstract

A novel series of 20 compounds containing 4-aminopyrazolo[3,4-d]pyrimidine core were synthesized, characterized and their chemical structures confirmed using spectroscopic techniques such as ¹H NMR, ¹³C NMR, IR, and HRMS. The compound's growth inhibitory activities were evaluated against 60 human tumor cell lines from nine panels: leukemia, non-small cell lung cancer (NSCLC), colon, central nervous system (CNS), melanoma, ovarian, renal, prostate, and breast cancer. Among all the compounds, 11, 12c, 12d, 12f, and 12j are active against different cancer cell lines. Between all the cell lines, compounds 12c, 12d, 12f, 12j, and 11 showed good inhibitory activity against renal cancer cell lines. From the five-dose study, based on IC₅₀ values, the order of activity of compounds against renal cancer cell lines was found to be 12c > 12f > 12c > 12j > 11 with 12c being the most potent, was better than sunitinib and sorafenib. Having been recognized as initial hits, these substances need additional pharmacological investigation.

Fig. 1. Pyrimidines in small-molecule inhibitors used in selective killing of tumorigenic cells.

Fig. 2. Design model for the novel molecules.

Scheme 1. Synthesis of novel 4-aminopyrazolo[3,4-d]pyrimidine amine derivative (11) that was used as starting material for the synthesis of the novel library.

Scheme 2. Synthesis of novel pyrazolopyrimidine derivatives (12a–12t).

Scheme 3. Model reaction for the synthesis of 12g.

Fig. 3. Depiction of average %GI exhibited by all compounds in the study, highlighting the compounds with >75% growth inhibition (in green), at 10 μM concentration.

Fig. 4. Cytotoxic activity trend in renal cancer sub-panel depicting the IC₅₀ value for compounds in the dose-dependent study.

Fig. 5. Dose–response curves in the renal cancer sub-panel depicting the IC₅₀ value for compound 12b in UO-31 tumour cell line.

Fig. 6. Structure–activity correlation chart for synthesized compounds (12a–12t) based on NCI-60 average growth inhibition percentage (%GI).

Fig. 7. Overview of structure–activity relationship.