a Na⁺ channel blocker; potent antiarrhythmic; local anesthetic.

C₁₉-diterpenoid alkaloid C₂₉H₃₇NO₆.HCl from plants of the Ranunculaceae family.

• Molecular Weight : 531 Da.
  
  
• Melting Point : 209-211 °C. (decomp. alcohol)
  
  
• Solubility in : water; moderately in methanol; not well in ethanol.
  
  
• Purity min. : 97 % (TLC, mass spectrometry, NMR).
  
  
• Biological Activity : Strongly antagonizes the effects of Aconitine; the basic mechanism of action is the inhibition of Na⁺ conductivity of excitable cells. The Na⁺ channel blockage level does not depend on the potential and stimulus intensity. Its antiarrhythmic activity level is higher than that of Quinidine, and its mechanism of action significantly differs from that of other class I antiarrhythmics.
  
  
• Toxicity (LD₅₀) : rats (i.v.): 5.0 mg/kg.
  
  
• Storage recommendations : - for experiments on antiarrhythmic effects: 0.05 mg/kg to 0.5 mg/kg; - for anesthetic activity on nerve terminals: 0.1% to 0.5% solution; - for in vitro experiments: 10-9-10-8 M solution. Store at +4°C, in dark place.
  
  
• Bibliography :
  
  1. Aneja et al., "The diterpene alkaloids: the structure and stereochemistry of heteratisine." Tetrahedron (1973). 29 (21):3297-3308