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.