Ajmalicine, also known as δ-yohimbine or raubasine, is an
antihypertensive
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke, heart failure, kidney failure and myocardial infa ...
drug
A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...
used in the treatment of high
blood pressure
Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...
. It has been marketed under numerous brand names including Card-Lamuran, Circolene, Cristanyl, Duxil, Duxor, Hydroxysarpon, Iskedyl, Isosarpan, Isquebral, Lamuran, Melanex, Raunatin, Saltucin Co, Salvalion, and Sarpan. It is an
alkaloid
Alkaloids are a broad class of natural product, naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids.
Alkaloids are produced by a large varie ...
Rauvolfia
''Rauvolfia'' (sometimes spelled ''Rauwolfia'') is a genus of evergreen trees and shrubs, commonly known as devil peppers, in the family Apocynaceae. The genus is named to honor Leonhard Rauwolf. The genus can mainly be found in Tropics, trop ...
'' spp., ''
Catharanthus roseus
''Catharanthus roseus'', commonly known as bright eyes, Cape periwinkle, graveyard plant, Madagascar periwinkle, old maid, pink periwinkle, rose periwinkle, is a perennial species of flowering plant in the family Apocynaceae. It is native and en ...
'', and ''
Mitragyna speciosa
''Mitragyna speciosa'' is a tropical evergreen tree of the Rubiaceae family (coffee family) native to Southeast Asia. It is indigenous to Cambodia, Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea, where its dark green, glossy leav ...
''.
Ajmalicine is
structurally
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
related to
yohimbine
Yohimbine, also known as quebrachine, is an indole alkaloid derived from the bark of the African tree '' Pausinystalia johimbe'' (yohimbe); also from the bark of the unrelated South American tree '' Aspidosperma quebracho-blanco''. Yohimbine is ...
,
rauwolscine
Rauwolscine, also known as isoyohimbine, α-yohimbine, and corynanthidine, is an alkaloid found in various species within the genera ''Rauvolfia'' and '' Corynanthe'' (including ''Pausinystalia''). It is a stereoisomer of yohimbine. Rauwolscine ...
derivative
In mathematics, the derivative is a fundamental tool that quantifies the sensitivity to change of a function's output with respect to its input. The derivative of a function of a single variable at a chosen input value, when it exists, is t ...
s. Like
corynanthine
Corynanthine, also known as rauhimbine, is an alkaloid found in the ''Rauvolfia'' and ''Corynanthe'' (including ''Pausinystalia'') genera of plants. It is one of the two diastereoisomers of yohimbine, the other being rauwolscine. It is also relat ...
antagonist
An antagonist is a character in a story who is presented as the main enemy or rival of the protagonist and is often depicted as a villain.α2-adrenergic receptors, underlying its hypotensive rather than hypertensive effects.
Additionally, it is a very strong inhibitor of the
CYP2D6
Cytochrome P450 2D6 (CYP2D6) is an enzyme that in humans is encoded by the ''CYP2D6'' gene. ''CYP2D6'' is primarily expressed in the liver. It is also highly expressed in areas of the central nervous system, including the substantia nigra.
CYP2 ...
liver enzyme, which is responsible for the breakdown of many drugs. Its binding affinity at this receptor is 3.30 nM.
Biosynthesis
Two moieties are involved in the biosynthesis of ajmalicine, the terpenoid moiety and the indole moiety. The terpenoid moiety is synthesized by the MEP pathway. The MEP pathway starts with pyruvate and D-glyceraldehyde-3-phosphate, followed by the involvement of DXS, DXR, MCT, MECS, HDS, and HDR genes. This results in isopentenyl diphosphate and dimethylallyl diphosphate which are then synthesized into secologanin. The indole moiety is brought about by the indole pathway, where tryptophan decarboxylase (TDC) catalyzes the formation of tryptamine from tryptophan. Strictosidine synthase (STR) then catalyzes the formation of strictosidine from the intermediates of the previous pathways. Strictosidine is the common precursor for all terpenoid indole alkaloids. Ajmalicine is finally synthesized under catalysis of strictosidine glucosidase (SGD).
See also
*
Corynanthine
Corynanthine, also known as rauhimbine, is an alkaloid found in the ''Rauvolfia'' and ''Corynanthe'' (including ''Pausinystalia'') genera of plants. It is one of the two diastereoisomers of yohimbine, the other being rauwolscine. It is also relat ...
*
Rauwolscine
Rauwolscine, also known as isoyohimbine, α-yohimbine, and corynanthidine, is an alkaloid found in various species within the genera ''Rauvolfia'' and '' Corynanthe'' (including ''Pausinystalia''). It is a stereoisomer of yohimbine. Rauwolscine ...
*
Spegatrine
Spegatrine is an alpha-1 adrenergic receptor, α1- and alpha-2 adrenergic receptor, α2-adrenergic receptor receptor antagonist, antagonist isolated from ''Rauvolfia verticillata''. Its Dimer (chemistry), dimer dispegatrine has greater antagonist ...
*
Yohimbine
Yohimbine, also known as quebrachine, is an indole alkaloid derived from the bark of the African tree '' Pausinystalia johimbe'' (yohimbe); also from the bark of the unrelated South American tree '' Aspidosperma quebracho-blanco''. Yohimbine is ...