Structural Analysis of Saxitoxin and Neosaxitoxin Toxins with Potential Therapeutic Targets

Historically, saxitoxin (STX) and its analogs, like neosaxitoxin (NeoSTX), have been restricted to scientific research due to their potent toxicity, despite their potential as therapeutic agents. This study aimed to evaluate the pharmacological versatility of STX and NeoSTX through molecular docking. Using the SwissTargetPrediction server, 18 potential human therapeutic targets were identified, with the 5-HT6 receptor being the primary target. Molecular docking assays were performed with AutoDock Vina version 1.1.2, and the lowest-energy pose for NeoSTX (−5.7 kcal/mol) suggested a stronger binding affinity compared to STX (−5.5 kcal/mol). The analysis of the binding mode revealed key interactions, including hydrogen bonds with Thr199 and hydrophobic contacts with Phe285. These findings provide robust hypotheses regarding the therapeutic potential of NeoSTX as a 5-HT6 receptor antagonist, supporting the development of novel bioactive agents derived from these marine toxins.