Chiral recognition of CIAC001 isomers in regulating pyruvate kinase M2 and mitigating neuroinflammation.

Chiral recognition plays a critical role in drug efficacy within biological systems. CIAC001, a cannabidiol (CBD) derivative that targets pyruvate kinase M2 (PKM2), has shown strong anti-neuroinflammatory and anti-morphine addiction effects. However, the chiral recognition of CIAC001, which contains multiple chiral centers, remains poorly understood. In this study, four chiral isomers of CIAC001 were synthesized, revealing distinct chiral recognition patterns for PKM2. Notably, (7S)-(-)-CIAC001 exhibited superior anti-neuroinflammation activity, with a significantly stronger binding affinity and a lower dissociation constant (2.2 μM) compared to its (7R)-(-) counterpart. Molecular dynamics simulations revealed that (7S)-(-)-CIAC001 forms π-π stacking interactions with phenylalanine at position 26 (F26) on two PKM2 subunits, contributing to its stronger binding energy. Substitution of F26 with alanine abolished the binding of (7S)-(-)-CIAC001, underscoring the importance of this residue. In in vivo assays, (7S)-(-)-CIAC001 more effectively inhibited IL-1β transcription, demonstrating greater anti-neuroinflammatory and anti-morphine addiction activity. This study highlights the differential chiral recognition of CIAC001 isomers by PKM2, with F26 identified as a key residue, providing valuable insights for the future development of chiral cannabinoid therapeutics.