A new structure of a serotonin salt: Comparison and conformational analysis of all known serotonin complexes

Four serotonin salt structures (serotonin adipate, C₁₀H ₁₃N₂O⁺·C₆H₉O ₄ ^-, is a previously unknown structure) were analysed to understand the influence of the anion on serotonin conformation. Hydrogen bonding alone favours a flat conformation, whereas additional stacking interactions between ions may possibly account for the nonplanar conformation. Since molecular conformation, stability and biological activity are interrelated, one can consider influencing the chemical and biological properties of serotonin by selecting an appropriate counter-ion for salt formation.