Ajmalan is a

parent hydride In chemistry, a parent hydride in IUPAC nomenclature refers to a main group compound with the formula , where A is a main group element. The names of parent hydrides end with ''-ane'', analogous with the nomenclature for alkanes. Derivatives of p ...

used in the IUPAC nomenclature of natural products and also in CAS nomenclature.. It is a 20-carbon alkaloid with six rings and seven chiral centres. The name is derived from

ajmaline Ajmaline (also known by trade names Gilurytmal, Ritmos, and Aritmina) is an alkaloid that is classified as a 1-A antiarrhythmic agent. It is often used to induce arrhythmic contraction in patients suspected of having Brugada syndrome. Individuals ...

, an antiarrhythmic alkaloid isolated from the roots of ''

Rauvolfia serpentina ''Rauvolfia serpentina'', the Indian snakeroot, devil pepper, or serpentine wood, is a species of flower in the milkweed family Apocynaceae. It is native to the Indian subcontinent and East Asia (from India to Indonesia). ''Rauvolfia'' is a pe ...

'' which is formally a dihydroxy-derivative of ajmalan. The –an ending indicates that ajmalan is partially

saturated Saturation, saturated, unsaturation or unsaturated may refer to: Chemistry * Saturation, a property of organic compounds referring to carbon-carbon bonds ** Saturated and unsaturated compounds **Degree of unsaturation ** Saturated fat or fatty ac ...

. Ajmaline itself is named after Hakim Ajmal Khan, a distinguished practitioner of the Unani school of traditional medicine in South Asia. The absolute configuration of the seven chiral carbon atoms in ajmalan is defined by convention, as is the numbering system. The stereochemistry is the same as that in naturally occurring

, and corresponds to (2''R'',3''S'',5''S'',7''S'',15''S'',16''R'',20''S'') using conventional numbering. Ajmalan can be systematically named as : or as :. Note that the numbering of the atoms in the systematic names is different from the conventional numbering of ajmalan.The numbering is also different between the von Baeyer name and the fusion name, given the different conventions which apply to the two methods of nomenclature. The ajmalan skeleton is similar to those of certain other alkaloids, and ajmalan could also be given the following semisystematic names: : :(2β,5β,7β,16''R'',20β)-1-methyl-2,7-dihydro-5,16:7,17-dicyclo corynan; :(2β,7β,16''R'',20β)-1-methyl-2,7,19,20-tetrahydro-7,17-cyclo sarpagan; :(2β,3α,7β,20β)-1-methyl-2,7,19,20-tetrahydro-3,4:7,17-dicyclo-22-nor vobasan; :(2β,5β,7β,16''R'',20β)-1-methyl-2,7-dihydro-5,16:7,17-dicyclo-17-seco yohimban. However, the relative complexity even of these names justifies the use of ajmalan as a defined parent hydride in alkaloid nomenclature.

References

{{reflist Alkaloids found in Apocynaceae Chemical nomenclature Heterocyclic compounds with 6 rings