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Ryanodine structure.png
CAS number 15662-33-6 YesY
PubChem 5114
ChemSpider 16736002 YesY
KEGG C08705 N
MeSH Ryanodine
Jmol-3D images Image 1
Molecular formula C25H35NO9
Molar mass 493.547 g/mol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N (verify) (what is: YesY/N?)
Infobox references

Ryanodine is a poisonous alkaloid found in the South American plant Ryania speciosa (Salicaceae). It was originally used as an insecticide.

The compound has extremely high affinity to the open-form ryanodine receptor, a group of calcium channels found in skeletal muscle, smooth muscle, and heart muscle cells. It binds with such high affinity to the receptor that it was used as a label for the first purification of that class of ion channels and gave its name to it.

At nanomolar concentrations, ryanodine locks the receptor in a half-open state, whereas it fully closes them at micromolar concentration. The effect of the nanomolar-level binding is that ryanodine causes release of calcium from calcium stores as the sarcoplasmic reticulum in the cytoplasm, leading to massive muscular contractions. The effect of micromolar-level binding is paralysis. This is true for both mammals and insects.

See also[edit]

  • Ryanoid, a class of insecticides with the same mechanism of action as ryanodine