Ryanodine

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

Ryanodine

Names
Preferred IUPAC name (1S,2R,2aS,2a1R,3S,3aS,6S,7R,7aR,9S,9aS)-1,2a,2a1,3a,7,9-Hexahydroxy-3,6,9a-trimethyl-1-(propan-2-yl)dodecahydro-3,9-methanobenzo[1,2]pentaleno[1,6-bc]furan-2-yl 1H-pyrrole-2-carboxylate
Identifiers
CAS Number	15662-33-6 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:8925 Y
ChEMBL	ChEMBL612231 N
ChemSpider	16736002 Y
IUPHAR/BPS	4303
KEGG	C08705 N
MeSH	Ryanodine
PubChem CID	5114
UNII	37H6ATE4SA Y
CompTox Dashboard (EPA)	DTXSID0032574
InChI InChI=1S/C25H35NO9/c1-12(2)22(31)17(34-16(28)14-7-6-10-26-14)23(32)18(4)11-21(30)19(22,5)25(23,33)24(35-21)15(27)13(3)8-9-20(18,24)29/h6-7,10,12-13,15,17,26-27,29-33H,8-9,11H2,1-5H3/t13-,15+,17+,18-,19+,20-,21-,22+,23+,24+,25+/m0/s1 Y Key: JJSYXNQGLHBRRK-SFEDZAPPSA-N Y InChI=1/C25H35NO9/c1-12(2)22(31)17(34-16(28)14-7-6-10-26-14)23(32)18(4)11-21(30)19(22,5)25(23,33)24(35-21)15(27)13(3)8-9-20(18,24)29/h6-7,10,12-13,15,17,26-27,29-33H,8-9,11H2,1-5H3/t13-,15+,17+,18-,19+,20-,21-,22+,23+,24+,25+/m0/s1 Key: JJSYXNQGLHBRRK-SFEDZAPPBA
SMILES C[C@H]1CC[C@@]2([C@@]3(C[C@]4([C@@]5([C@]([C@H]([C@@]3([C@]5([C@]2([C@@H]1O)O4)O)O)OC(=O)c6ccc[nH]6)(C(C)C)O)C)O)C)O
Properties
Chemical formula	C25H35NO9
Molar mass	493.553 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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 muscle contractions. The effect of micromolar-level binding is paralysis. This is true for both mammals and insects.

See also

• Diamide insecticides, a class of insecticides with the same mechanism of action as ryanodine
• Ryanodine receptor
• Dihydropyridine channel

Further reading

• Santulli, Gaetano; Marks, Andrew (2015). "Essential Roles of Intracellular Calcium Release Channels in Muscle, Brain, Metabolism, and Aging". Current Molecular Pharmacology. 8 (2): 206–222. doi:10.2174/1874467208666150507105105. PMID 25966694.
• Bertil Hille, Ionic Channels of Excitable Membranes, 2nd edition, Sinauer Associates, Sunderland, MA, 01375, ISBN 0-87893-323-9