Alazocine ((-)-SKF-10,047), or (-)-N-allylnormetazocine ((-)-ANMC), was the first drug discovered to act as a σ1 receptor agonist (Ki = 24 nM). It has no significant affinity for the σ2 receptor. Alazocine also acts as a κ-opioid receptor agonist (Ki = 0.4 nM), and to a much lesser extent, as an NMDA receptor antagonist (Ki = 587 nM).