Title: Ajmaline
CAS Registry Number: 4360-12-7
CAS Name: Ajmalan-17,21-diol
Additional Names: rauwolfine
Trademarks: Aritmina (Altana); Gilurytmal (Solvay); Ritmos (Sanofi-Synthelabo); Tachmalin (AWD)
Molecular Formula: C20H26N2O2
Molecular Weight: 326.43
Percent Composition: C 73.59%, H 8.03%, N 8.58%, O 9.80%
Literature References: From roots of Rauwolfia serpentina (L.) Benth. (Ophioxylon serpentinum L.), Apocynaceae. Isolation: S. Siddiqui, R. H. Siddiqui, J. Indian Chem. Soc. 8, 667 (1931); 9, 539 (1932); 12, 37 (1935); L. van Itallie, A. J. Steenhauer, Arch. Pharm. 270, 313 (1932). Structure: A. Chatterjee, S. Bose, J. Indian Chem. Soc. 31, 17 (1954); F. A. L. Anet et al., J. Chem. Soc. 1954, 1242. Stereochemistry: M. F. Bartlett et al., J. Am. Chem. Soc. 84, 622 (1962). Synthesis: S. Masamune et al., ibid. 89, 2506 (1967); E. E. Van Tamelen, L. K. Oliver, ibid. 92, 2136 (1970); K. Mashimo, Y. Sato, Chem. Pharm. Bull. 18, 353 (1970). Physico-chemical properties: A. Petter, Arzneim.-Forsch. 24, 874 (1974). Antiarrhythmic activity: A. Petter, K. Engelmann, ibid. 876. Reviews: R. Robinson in Festschrift Arthur Stoll (Birkhäuser-Verlag, Basel, 1957) pp 457-467; A. Koskinen, M. Lounasmaa in Progress in the Chemistry of Natural Products vol. 43, W. Herz et al., Eds. (Springer-Verlag, New York, 1983) pp 268-346.
Properties: Pale amber, solvated, tetragonal prisms from methanol, C20H26N2O2.CH3OH, mp 158-160°. [a]D18 +131° (c = 0.4 in chloroform). Anhydr mp 205-207°. [a]D20 +144° (c = 0.8 in chloroform). uv max (ethanol): 247, 295 nm (log e 3.94, 3.49). Sol in methanol, ethanol, ether, chloroform; slightly sol in water.
Melting point: mp 158-160°; mp 205-207°
Optical Rotation: [a]D18 +131° (c = 0.4 in chloroform); [a]D20 +144° (c = 0.8 in chloroform)
Absorption maximum: uv max (ethanol): 247, 295 nm (log e 3.94, 3.49)
Derivative Type: Hydrochloride dihydrate
Molecular Formula: C20H26N2O2.2HCl.2H2O
Molecular Weight: 435.39
Percent Composition: C 55.17%, H 7.41%, N 6.43%, O 14.70%, Cl 16.29%
Properties: Hexagonal bipyramidal crystals from water, mp 140°. [a]D18 +96.6°. One gram dissolves in 40 ml water.
Melting point: mp 140°
Optical Rotation: [a]D18 +96.6°
Therap-Cat: Antihypertensive; antiarrhythmic.
Keywords: Antiarrhythmic; Antihypertensive.
Ajowan Oil Ajugarins Ajulemic Acid Aklomide Akuammicine

Systematic (IUPAC) name
(17R,21β)-ajmalan- 17,21-diol
(1R,9R,10S,13R,14R,16S,18S)- 13-ethyl- 8-methyl- 8,15-diazahexacyclo [,9.02,7.010,15.012,17] nonadeca- 2(7),3,5-triene- 14,18-diol
Clinical data
AHFS/Drugs.com International Drug Names
Legal status  ?
CAS number 4360-12-7 YesY
ATC code C01BA05
PubChem CID 20367
DrugBank DB01426
ChemSpider 10469368 YesY
UNII 1PON08459R YesY
KEGG D00199 N
Chemical data
Formula C20H26N2O2 
Mol. mass 326.433 g/mol
 N (what is this?)  (verify)

Ajmaline is an alkaloid that is class Ia antiarrhythmic agent. It is often used to bring out typical findings of ST elevations in patients suspected of having Brugada syndrome.

The compound was first isolated by Salimuzzaman Siddiqui in 1931 [1] from the roots of Rauwolfia serpentina. He named it ajmaline, after Hakim Ajmal Khan, one of the most illustrious practitioners of Unani medicine in South Asia.[2]