a blocker of Ca²⁺ channels of sarcoplasmic reticulum; exhibits complex effects on heart, skeletal and smooth muscles, nervous system and other organs.

Alkaloid C₂₅H₃₃NO₉ from the plant Ryania speciosa, Flacourtiaceae.

• Molecular Weight : 491 Da.
  
  
• Melting Point : not determined.
  
  
• Solubility in : well in water under heating, methanol and ethanol.
  
  
• Purity min. : 97 % (HPLC).
  
  
• Toxicity (LD₅₀) : mammals (orally): * 1.5 g/kg.
  
  
• Storage recommendations : Store tightly sealed at +4°C, in dark place.
  
  
• CAS Reg. No. : 94513-55-0
  
  
• Merck Index 11th Ed. : 8279
  
  
• Bibliography :
  
  1. Sutko et al., "Ryanodine : a modifier of reticulum sarcoplasmic calcium release in striated muscle." Fed. Proc. 1985 44:2984