{{chembox | Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 464384841 | ImageFile = Ryanodine.svg | ImageSize = 240px | PIN = (1''S'',2''R'',2a''S'',2a<sup>1</sup>''R'',3''S'',3a''S'',6''S'',7''R'',7a''R'',9''S'',9a''S'')-1,2a,2a<sup>1</sup>,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 1''H''-pyrrole-2-carboxylate | OtherNames = |Section1={{Chembox Identifiers | IUPHAR_ligand = 4303 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID = 16736002 | 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 | InChIKey = JJSYXNQGLHBRRK-SFEDZAPPBA | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 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 | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = JJSYXNQGLHBRRK-SFEDZAPPSA-N | CASNo_Ref = {{cascite|correct|CAS}} | CASNo = 15662-33-6 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 37H6ATE4SA | PubChem = 5114 | ChEMBL_Ref = {{ebicite|changed|EBI}} | ChEMBL = 612231 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 8925 | 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 | MeSHName = Ryanodine | KEGG_Ref = {{keggcite|changed|kegg}} | KEGG = C08705 }} |Section2={{Chembox Properties | C=25 | H=35 | N=1 | O=9 | Appearance = | Density = | MeltingPt = | BoilingPt = }} |Section3={{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} }}
'''Ryanodine''' is a poisonous diterpenoid found in the South American plant ''Ryania speciosa'' (Salicaceae). It was isolated by Merck chemists in the 1940s from an extract of the plant by following its insecticidal activity.<ref>{{Cite journal |last1=Rogers |first1=Edward F. |last2=Koniuszy |first2=Frank R. |last3=Shavel |first3=John Jr. |last4=Folkers |first4=Karl |date=1948 |title=Plant Insecticides. I. Ryanodine, A New Alkaloid from Ryania Speciosa Vahl. |url=https://doi.org/10.1021/ja01189a074 |journal=Journal of the American Chemical Society |volume=70 |issue=9 |pages=3086–3088 |doi=10.1021/ja01189a074 |pmid=18882544 |bibcode=1948JAChS..70.3086R |url-access=subscription }}</ref> It was sold since the 1940s in a partially purified form as an insecticide,<ref>{{cite book |last1=Metcalf Deceased |first1=Robert L. |last2=Horowitz |first2=Abraham Rami |title=Ullmann's Encyclopedia of Industrial Chemistry |chapter=Insect Control, 2. Individual Insecticides |date=2014 |pages=1–94 |doi=10.1002/14356007.s14_s01 |isbn=978-3-527-30673-2 }}</ref><ref>{{Cite book |last1=Jacobson |first1=Martin |url=https://archive.org/details/naturallyoccurri0000unse |title=Naturally Occurring Insecticides |last2=Crosby |first2=Donald G. |publisher=Marcel Dekker |year=1971 |location=New York |pages=198–205 |chapter=Chapter 5 II C. Ryania |isbn=978-0-8247-1325-6 }}</ref> and used in organic farming, but was removed from the market in 1997.<ref>{{Cite web |last=Wilhite |first=Mark |date=March 1999 |title=Reregistration Eligibility Decision (RED) Fact sheet for Ryanodine |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-071502_1-Mar-99.pdf |access-date=27 April 2026 |website=Office of Pesticide Programs, Environmental Protection Agency}}</ref>
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.<ref name="Marks2015">{{cite journal|last1=Santulli|first1=Gaetano|last2=Marks|first2=Andrew|title=Essential Roles of Intracellular Calcium Release Channels in Muscle, Brain, Metabolism, and Aging|journal=Current Molecular Pharmacology|volume=8|issue=2|year=2015|pages=206–222|issn=1874-4672|doi=10.2174/1874467208666150507105105|pmid=25966694}}</ref> 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.<ref>{{cite journal | last1 = Van Petegem | first1 = F | year = 2012 | title = Ryanodine receptors: structure and function | journal = The Journal of Biological Chemistry | volume = 287 | issue = 38| pages = 31624–32 | doi = 10.1074/jbc.r112.349068 | pmid = 22822064 | pmc = 3442496 | doi-access = free }}</ref>
== See also == * Diamide insecticides, a class of insecticides with the same mechanism of action as ryanodine * Ryanodine receptor * Dihydropyridine channel
== References == {{Reflist}}
==Further reading== * {{cite journal | doi = 10.2174/1874467208666150507105105 | title = Essential Roles of Intracellular Calcium Release Channels in Muscle, Brain, Metabolism, and Aging | date = 2015 | last1 = Santulli | first1 = Gaetano | last2 = Marks | first2 = Andrew | journal = Current Molecular Pharmacology | volume = 8 | issue = 2 | pages = 206–222 | pmid = 25966694 }} * Bertil Hille, ''Ionic Channels of Excitable Membranes'', 2nd edition, Sinauer Associates, Sunderland, MA, 01375, {{ISBN|0-87893-323-9}}
{{Insecticides}}
Category:Insecticides Category:Pyrroles Category:Carboxylate esters Category:Alcohols Category:Cyclopentanes Category:Diterpene alkaloids Category:Isopropyl compounds Category:Plant toxins