Discovery and Characterization of Novel Spirotriazoloquinazolines as Potential Neuroprotectors: Synthesis, Computational Screening, and Preliminary In Vivo Evaluation

This study describes the rational design, synthesis, and evaluation of forty 2'-R-6'H-spiro(cycloalkyl/heterocyclyl)[1,2,4]triazolo[1,5-c]quinazolines as potential neuroprotective agents targeting multiple receptor systems implicated in cognitive dysfunction. The molecular design integrated structural features from established nootropic and anxiolytic pharmacophores to create compounds with putative multi-target activity. In silico ADMET analyses assessed drug-likeness parameters, while molecular docking studies evaluated binding interactions with nine neuroreceptor targets: glutamate GluA3, GABA(A)R, dopamine D2, serotonin 5-HT1A and 5-HT7, cannabinoid CB2, muscarinic M2 acetylcholine, corticotropin-releasing factor receptor 1 (CRF1R), and metabotropic glutamate receptor 5 (mGluR5). Based on computational predictions, selected compounds underwent preliminary in vivo screening using a ketamine-induced cognitive impairment model in rats. Behavioral assessments examined anxiety-related responses and cognitive performance relative to piracetam and fabomotizole controls. Biochemical analyses measured inflammatory markers (IL-1β, caspase-1), cell survival indicators (Bcl-2), and hypoxic adaptation responses (HIF-1 mRNA). Docking studies indicated favorable binding profiles across tested receptor targets compared to reference ligands, with calculated affinities suggesting potential modulatory interactions. The experiments showed that compounds 25, 26, and 32 attenuated ketamine-induced behavioral alterations, demonstrating effects in anxiety reduction and cognitive performance that appeared numerically greater than piracetam and fabomotizole, though the magnitude and statistical robustness of these differences require further characterization. Compound 31 reduced IL-1β expression by 72% and caspase-1 by 80% relative to ketamine-treated controls. Compound 26 increased Bcl-2 expression by 96% and HIF-1 mRNA levels by 3.5-fold compared to control conditions. These findings suggest that spirotriazoloquinazolines may function as positive modulators at cognitive-enhancing receptors, potentially exerting neuroprotective effects through anti-inflammatory and anti-apoptotic mechanisms. Further investigation is necessary to validate the observed effects, establish dose-response relationships, and elucidate the molecular mechanisms underlying the apparent neuroprotective properties of these compounds.