Synthesis, Characterization, and Biological Effects of Chloro-Cathinones: Toxicity and Potential Neurological Impact

Cathinones, a class of synthetic new psychoactive substances (NPSs), continue to emerge and pose public threats. Government control efforts often lead to the emergence of new isomers, which have adverse repercussions on NPSs identification and risk prediction. This work reports on the synthesis and structural characterization of twenty chloro-cathinones, including different isomers, to create analytical data to facilitate their identification in forensic and clinical contexts. Additionally, the potential of these cathinones to cause neuronal damage was evaluated. In vitro cytotoxicity was assessed using a differentiated human neuroblastoma cell line (SH-SY5Y) as a dopaminergic neuronal model. The tested cathinones showed LC₅₀ values from 0.6 to 2.5 mM, with 4-CBC being the most cytotoxic. The most toxic cathinones increase reactive oxygen species levels and/or cause mitochondrial membrane potential depolarization. Furthermore, this study explored, for the first time, the effect of cathinones on the cholinergic system through acetylcholinesterase (AChE) inhibition. All tested cathinones inhibited AChE with IC₅₀ values between 0.1 and 2 mM. Molecular docking analysis revealed that the most inhibitory cathinones interacted with the CASs and PASs in AChE's active gorge. These findings provide valuable insights into the effects of cathinones, highlighting potential health risks and structural features that may influence their toxicity towards the cholinergic system and neuronal damage.