Title: Ryanodine
CAS Registry Number: 15662-33-6
CAS Name: Ryanodol 3-(1H-pyrrole-2-carboxylate)
Molecular Formula: C25H35NO9
Molecular Weight: 493.55
Percent Composition: C 60.84%, H 7.15%, N 2.84%, O 29.18%
Literature References: Insecticidal principle isolated from Ryania speciosa Vahl., Flacourtiaceae: E. F. Rogers et al., J. Am. Chem. Soc. 70, 3086 (1948); R. B. Kelly et al., Can. J. Chem. 29, 905 (1951). Structure: D. R. Babin et al., Experientia 21, 425 (1965); J. Santroch et al., ibid. 21, 730 (1965); K. Wiesner et al., Tetrahedron Lett. 1967, 221; K. Wiesner, Adv. Org. Chem. 8, 295 (1972). Crystal structure: S. N. Srivastava, M. Przybylska, Can. J. Chem. 46, 795 (1968). 1H-NMR: A. L. Waterhouse et al., Chem. Commun. 1984, 1265. Synthetic studies: P. Deslongchamps, Pure Appl. Chem. 49, 1329 (1977). Effect on calcium ion uptake by cardiac sarcoplasmic reticulum vesicles: L. R. Jones et al., J. Pharmacol. Exp. Ther. 209, 48 (1979); L. R. Jones, S. E. Cala, J. Biol. Chem. 256, 11809 (1981).
Properties: Crystals, dec 219-220°. [a]D25 +26° (methanol). uv max (alc): 268.5 nm (log e 4.18). Sol in water, alcohol, acetone, ether, chloroform. Practically insol in benzene, petr ether.
Optical Rotation: [a]D25 +26° (methanol)
Absorption maximum: uv max (alc): 268.5 nm (log e 4.18)
Use: Insecticide.
(S,S)-Chiraphos [S-(all-E)]-3-(1,3,5,7,9-Dodecapentaenyloxy)-1,2-propanediol Sabadilla Sabadine Saccharin

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
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ryanodine is a poisonous alkaloid found in the South American plant Ryania speciosa (Flacourtiaceae). 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.