Rational design, synthesis and biological evaluation of novel 2-(substituted amino)-[1,2,4]triazolo[1,5-a]pyrimidines as novel tubulin polymerization inhibitors

Abstract

Following our previously reported compound 3, we designed and synthesized a series of new 2-(substituted amino)- [1,2,4]triazolo[1,5-a]pyrimidines as potential tubulin polymerization inhibitors. Among them, analogue 4k, having a 3-hydroxy-4-methoxyphenylamino group, was observed to display excellent antiproliferative activity toward HeLa, HCT116, A549, and T47D with the IC₅₀ values of 0.31, 1.28, 3.99 and 10.32 μM, respectively, which were approximately 32, 48, 4, and 5-fold improvement compared with 3. Importantly, 4k possessed significant selectivity in inhibiting cancer cell lines over the normal HEK293 cells. Moreover, futher mechanism analysis demonstrated that 4k caused G2/M arrest, induced cells apoptosis in HeLa cells, and manifested significant tubulin polymerization inhibitory activity with the IC₅₀ value of 4.9 μM, which is comparable to CA-4 (IC₅₀ = 4.2 μM). The observations performed in this study reveal that 2-arylamino- [1,2,4]triazolo[1,5-a]pyrimidines represent a novel class of tubulin polymerization inhibitors with potent antiproliferative efficacy.

Keywords: 2-Arylamino-[1,2,4]triazolo[1,5-a]pyrimidine; Anticancer agents; Tubulin inhibitors.