1,3,5-Triazine: A Promising Molecular Scaffold for Novel Agents for the Treatment of Alzheimer's Disease

Currently, Alzheimer's disease (AD) is one of the most frequent forms of dementia. From a molecular perspective, the molecular characteristics that better define this disease consist of abnormal protein deposits between neuronal cells, namely senile plaques (SPs) and neurofibrillary tangles (NFTs), consisting of protein aggregates of amyloid-beta and hyperphosphorylated tau protein, respectively. In addition to these protein aggregates, a third molecular hallmark of AD consists of depleted neurotransmitter acetylcholine levels. To date, the treatments developed for this disease are mostly focused on the use of AChE inhibitors, presenting only a symptomatic approach against the disease instead of a cure. Triazines are nitrogen-containing heterocyclic compounds that, throughout the years, have attracted a lot of curiosity from medicinal chemists for presenting numerous biological properties and being widely present in nature. In particular, this class of compounds has been associated with inhibiting several biological targets, emerging as a promising class for developing new pharmacological agents. However, there is still a scarcity of knowledge regarding the potential of this type of compound against any of the hallmarks of AD. For this reason, this paper intends to fulfill this absence by highlighting the potential of a subclass of triazines, 1,3,5-triazines (sym-triazines), as promising molecules for developing novel AD treatments. Thus, an in-depth analysis of 1,3,5-triazine derivatives is performed regarding its inhibitory activity against AChE (cholinergic hypothesis) and its capability to inhibit amyloid-beta formation and aggregation (amyloid hypothesis). Through this analysis, it is possible to indicate some structural features optimal for each described activity, a compilation that we believe to be essential for the scientific community in this never-ending pursuit.