Loganin is one of the best-known of the

iridoid Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically found in plants as glycosides, mos ...

glycosides In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. ...

. It is named for the

Loganiaceae The Loganiaceae are a family of flowering plants classified in order Gentianales. The family includes up to 13 genera, distributed around the world's tropics. There are not any great morphological characteristics to distinguish these taxa from o ...

, having first been isolated from the seeds of a member of that plant family, namely those of ''

Strychnos nux-vomica ''Strychnos nux-vomica'', the strychnine tree, also known as nux vomica, poison fruit, semen strychnos, and quaker buttons, is a deciduous tree native to India and to southeast Asia. It is a medium-sized tree in the family Loganiaceae that grow ...

''. It also occurs in ''

Alstonia boonei ''Alstonia boonei'' is a very large, deciduous, tropical-forest tree belonging to the family Apocynaceae. It is native to tropical West Africa, with a range extending into Ethiopia and Tanzania. Its common name in the English timber trade is che ...

'' (

Apocynaceae Apocynaceae (from ''Apocynum'', Greek for "dog-away") is a family of flowering plants that includes trees, shrubs, herbs, stem succulents, and vines, commonly known as the dogbane family, because some taxa were used as dog poison Members of the ...

), a medicinal tree of West Africa and in the medicinal/

entheogenic Entheogens are psychoactive substances that induce alterations in perception, mood (psychology), mood, consciousness, cognition, or behavior for the purposes of engendering spiritual development or otherwiseRätsch, Christian, ''The Encyclop ...

shrub

Desfontainia spinosa ''Desfontainia'' is a genus of flowering plants in the family Columelliaceae, though it was placed formerly in Loganiaceae, Potaliaceae (later subsumed in Gentianaceae), or a family of its own, Desfontainiaceae. The genus was named for the Fr ...

(

Columelliaceae Columelliaceae is a family of trees and shrubs native to the Andes of South America. In the APG II taxonomy it is placed in the order Lamiales, but a 2008 study suggested that the family is sister to the Bruniaceae, and the Angiosperm Phylogen ...

) native to

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

and

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Biosynthesis

Loganin is formed from

loganic acid Loganic acid is an iridoid Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically foun ...

by the enzyme loganic acid O-methyltransferase (LAMT). Loganin then becomes a substrate for the enzyme

secologanin synthase In enzymology, a secologanin synthase (, was wrongly classified as in the past) is an enzyme that catalyzes the chemical reaction :loganin + NADPH + H+ + O2 \rightleftharpoons secologanin + NADP+ + 2 H2O The 4 substrates of this enzyme are lo ...

(SLS) to form secologanin, a

secoiridoid Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically found in plants as glycosides, mos ...

monoterpene Monoterpenes are a class of terpenes that consist of two isoprene units and have the molecular formula C10H16. Monoterpenes may be linear (acyclic) or contain rings (monocyclic and bicyclic). Modified terpenes, such as those containing oxygen funct ...

found as part of ipecac and terpene

indole alkaloid Indole alkaloids are a class of alkaloids containing a structural moiety of indole; many indole alkaloids also include isoprene groups and are thus called terpene indole or secologanin tryptamine alkaloids. Containing more than 4100 known diffe ...

References

{{reflist Iridoid glycosides Cyclopentanes