Potent antiarrhythmic (class I), with weak hypotensive and N-cholinoblocking effects.

Diterpenoid alkaloid C₂₂H₃₃NO₃ from plants of the Aconitum genus, Ranunculaceae

• Molecular Weight : 359 Da.
  
  
• Melting Point : 162-164 °C
  
  
• Solubility in : well in chloroform; moderately in acetone and methanol; not well in water.
  
  
• Purity min. : 91%. TLC [silicagel, chloroform:methanol (9:1)]
  
  
• Physical Form : yellowish crystal powder.
  
  
• Biological Activity : Napelline has a stronger antiarrhythmic activity than Quinidine or Procaïnamide. 10-4 - 10-5 M block inward Na+ currents.[3]
  
  
• Toxicity (LD₅₀) : mice (i.v.) : 87.5 mg/kg mice (i.p.) : 280 mg/kg
  
  
• Storage recommendations : Stable in dry state; store at 4°C, in dark place. Solutions for experiments in vitro: 10-6 to 10-5 M; doses for one experiment in vivo: 10-20 mg/kg.
  
  
• CAS Reg. No. : 5008-52-6
  
  
• Merck Index 11th Ed. : 6286
  
  
• Bibliography :
  
  1. "The Alkaloids" R.H.F. Manske Ed. (Academic Press Inc., New-York) (1955). 4:291
  2. Okamoto et al., Chem. and Pharm. Bull. (1965) (Japan). 13:1270
  3. Djahangirov et al., "Pharmacology of the alkaloids Napelline and Heteratisine" Rpts. Acad. Sciences Uzb. (1977) (Russian). 3:50-51