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

Alkaloid C₂₅H₃₅NO₉ from the plant Ryania speciosa, Flacourtiaceae.

• Molecular Weight : 493.55 Da.
  
  
• Melting Point : 219-220 °C.
  
  
• Solubility in : heating water, methanol and ethanol.
  
  
• Purity min. : 99 % (HPLC).
  
  
• Toxicity (LD₅₀) : mammals (orally): ~ 1.5 g/kg.
  
  
• Storage recommendations : Store at +4°C, in dark place.
  
  
• CAS Reg. No. : 15662-33-6
  
  
• 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