4-{3-[(Pyridin-4-ylmethyl)amino]-[1,2,4]triazolo[4,3-b][1,2,4]triazin-6-yl}phenol: An improved anticancer agent in hepatocellular carcinoma and a selective MDR1/MRP modulator.

Hepatocellular carcinoma is the most common type of primary liver cancer. However, multidrug resistance (MDR) is a major obstacle to the effective chemotherapy of cancer cells. This report documents the rational design, synthesis, and biological evaluation of a novel series of triazolotriazines substituted with CH2NH-linked pyridine for use as dual c-Met/MDR inhibitors. Compound 12g with IC50 of 3.06 µM on HepG2 cells showed more potency than crizotinib (IC50 = 5.15 µM) in the MTT assay. In addition, 12g inhibited c-Met kinase at a low micromolar level (IC50 = 0.052 µM). 12g significantly inhibited P-gp and MRP1/2 efflux pumps in both cancerous HepG2 and BxPC3 cells starting from the lower concentrations of 3 and 0.3 µM, respectively. 12g did not inhibit MDR1 and MRP1/2 in noncancerous H69 cholangiocytes up to the concentration of 30 and 60 µM, respectively. Current results highlighted that cancerous cells were more susceptible to the effect of 12g than normal cells, in which the inhibition occurred only at the highest concentrations, suggesting a further interest in 12g as a selective anticancer agent. Overall, 12g, as a dual c-Met and P-gp/MRP inhibitor, is a promising lead compound for developing a new generation of anticancer agents.

Pharmacologic Activities of 5, 6-Diaryl/heteroaryl-3-substituted-1, 2, 4- triazines as a Privileged Scaffold in Drug Development.

1, 2, 4-Triazine derivatives have received much attention due to their multifunctional nature, especially in diverse pharmacological properties as well as a key fragment in many drug candidates. Introduction of a vicinal 5, 6-diaryl/heteroaryl moiety on the 1, 2, 4-triazine ring has attracted plentiful attention in the field of medicinal chemistry. 5, 6-Diaryl/heteroaryl-3-substituted-1, 2, 4- triazine is a prominent scaffold in many drug candidates, which has shown a wide range of pharmacological activities such as anti-diabetic, antifungal, anti-inflammatory, anticancer, anti-HIV, neuroprotective, anticonvulsant, anti-Alzheimer, anti-Parkinson, and antioxidant. In this review, we have discussed synthesis, various pharmacological activities of 5, 6-diaryl/heteroaryl-3-substituted-1, 2, 4- triazines, their structure-activity relationship (SAR), pharmacophoric elements, and their mechanism of action reported in the published articles during 2000-2019. Evaluation of compounds by PAINS filtering tool was accomplished and showed that this versatile structure could be considered as a privileged structure. Compilation of the biological data confirmed that position 3 of the 1,2,4-triazine is a key location to determine the affinity and selectivity of the 5,6-diaryl/heteroaryl-3-substituted-1, 2, 4- triazines towards different biologic targets. Specific geometrical and thermodynamic characters of this motif have prompted it as a frequent hitter.