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, mo ...
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, 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 grows ...
''. It also occurs in ''
Alstonia boonei'' (
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. Notable mem ...
),
a medicinal tree of West Africa and in the medicinal/
entheogenic
Entheogens are psychoactive substances used in spiritual and religious contexts to induce altered states of consciousness. Hallucinogens such as the psilocybin found in so-called "magic" mushrooms have been used in sacred contexts since ancie ...
shrub
Desfontainia spinosa (
Columelliaceae) native to
Central America
Central America is a subregion of North America. Its political boundaries are defined as bordering Mexico to the north, Colombia to the southeast, the Caribbean to the east, and the Pacific Ocean to the southwest. Central America is usually ...
and
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...
.
Biosynthesis
Loganin is formed from
loganic acid
Loganic acid is an iridoid. Loganic acid is synthesized from 7-deoxyloganic acid by the enzyme 7-deoxyloganic acid hydroxylase (7-DLH). It is a substrate for the enzyme loganate O-methyltransferase
In enzymology, a loganate O-methyltransferas ...
by the enzyme
loganic acid O-methyltransferase (LAMT). Loganin then becomes a substrate for the enzyme
secologanin synthase (SLS) to form secologanin, a
secoiridoid 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 func ...
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 differ ...
s.
References
{{reflist
Iridoid glycosides
Cyclopentanes