Clerodane diterpenes, sometimes referred to as clerodane diterpenoids, are a large group of secondary metabolites that have been isolated from several hundreds of different plant species, as well as fungi, bacteria and marine sponges. They are bicyclic

terpene Terpenes () are a class of natural products consisting of compounds with the formula (C5H8)n for n ≥ 2. Terpenes are major biosynthetic building blocks. Comprising more than 30,000 compounds, these unsaturated hydrocarbons are produced predomi ...

s that contain 20 carbons and a

decalin Decalin (decahydronaphthalene, also known as bicyclo .4.0ecane and sometimes decaline), a bicyclic organic compound, is an industrial solvent. A colorless liquid with an aromatic odor, it is used as a solvent for many resins or fuel additives. I ...

core.

Classification

The clerodane diterpenes are classified into four groups ''trans''-''cis'' (TC), ''trans''-trans (TT), ''cis''-''cis'' (CC), and ''cis''-''trans'' (TC) based on the relative stereochemistry at the decalin junction (''trans'' or ''cis'') and the relative stereochemistry of the substituents at C-8 and C-9 (''trans'' or ''cis''). The absolute stereochemistry of the clerodanes is classified as ''neo'' (shown below) or ''ent''-''neo'' (enantiomeric to ''neo''). The ''neo''-clerodanes share the same absolute stereochemistry as clerodin. Approximately 25% of clerodanes have the 5:10 ''cis'' ring junction. The remaining 75% have a ''trans'' 5:10 ring junction. Clerodane-skeleton-b

Biosynthesis

They are structurally related to the bicyclic

labdane Labdane is a natural bicyclic diterpene. It forms the structural core for a wide variety of natural products collectively known as ''labdanes'' or ''labdane diterpenes''. The labdanes were so named because the first members of the class were ori ...

diterpenes. Its biosynthesis in plants (mostly present in the families

Lamiaceae The Lamiaceae ( ) or Labiatae are a family (biology), family of flowering plants commonly known as the mint, deadnettle, or sage family. Many of the plants are aromatic in all parts and include widely used culinary herbs like basil (herb), ba ...

and

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

) takes place in the

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

s. Some forms can be useful intermediates in organic synthesis. Some clerodanes like clerodin (3-desoxy-caryoptinol) from the leaves of '' Clerodendrum infortunatum'' (

Verbenaceae The Verbenaceae ( ), the verbena family or vervain family, is a family of mainly tropical flowering plants. It contains trees, shrubs, and herbs notable for heads, spikes, or clusters of small flowers, many of which have an aromatic smell. T ...

) have

anthelminthic Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them without causing significant damage to the host. They may also ...

properties, others like are repellent to herbivore predators (mostly insects and their larvae) or have a very bitter taste, such as gymnocolin. Some examples for clerodanes are I to V extracted from bugleweeds like '' Ajuga remota'', ''

Ajuga ciliata ''Ajuga'' , also known as bugleweed,Bailey, L.H.; Bailey, E.Z.; the staff of the Liberty Hyde Bailey Hortorium. 1976. ''Hortus third: A concise dictionary of plants cultivated in the United States and Canada''. Macmillan, New York. ground pine, c ...

'', '' Ajuga decumbens'', common skullcap (''Scutellaria galericulata''), and ''germanders (Teucrium sp.''), cascarillin from '' Croton eluteria'', from ''

Jateorhiza columba ''Jateorhiza palmata'' (calumba) is a perennial climbing plant from East Africa. It contains isoquinoline alkaloids and is used mainly as a bitter tonic especially in cases of anorexia nervosa Anorexia nervosa (AN), often referred to simp ...

'', ''

Jateorhiza palmata ''Jateorhiza palmata'' (calumba) is a perennial climbing plant from East Africa. It contains isoquinoline alkaloids and is used mainly as a bitter tonic especially in cases of anorexia nervosa. It contains no tannins, hence it can be safely used ...

'' and

guduchi ''Tinospora cordifolia'', the heart-leaved moonseed, is a herbaceous vine of the family Menispermaceae native to South and Southeast Asia. It has been used in Ayurveda in an attempt to treat various disorders. There is no good evidence ''Tinospo ...

(''

Tinospora cordifolia ''Tinospora cordifolia'', the heart-leaved moonseed, is a herbaceous vine of the family Menispermaceae native to South and Southeast Asia. It has been used in Ayurveda in an attempt to treat various disorders. There is no good evidence ''Tinospo ...

''), gymnocolin from ''

Gymnocolea inflata ''Gymnocolea'' is a genus of liverworts in the family Anastrophyllaceae. The genus has cosmopolitan distribution in the northern hemisphere The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the S ...

'', hardwickiic acid from

Hardwickia ''Hardwickia'' is a monotypic genus of flowering plant in the subfamily Detarioideae of the legume family, Fabaceae. The only species is the anjan, ''Hardwickia binata'', a tree which is native to India and Bangladesh, and which grows to height o ...

species (

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

). Neo-clerodane diterpenes can have

hallucinogenic Hallucinogens, also known as psychedelics, entheogens, or historically as psychotomimetics, are a large and diverse class of psychoactive drugs that can produce altered states of consciousness characterized by major alterations in thought, moo ...

properties such as

salvinorin A Salvinorin A is the main active psychotropic molecule in '' Salvia divinorum''. Salvinorin A is considered an atypical dissociative hallucinogen. It is structurally distinct from other naturally occurring hallucinogens (such as DMT, psil ...

, a ''trans''-neoclerodane diterpene from ''

Salvia divinorum ''Salvia divinorum'' (; also called ska maría pastora, seer's sage, yerba de la pastora, magic mint or simply salvia) is a species of plant in the sage genus ''Salvia'', known for its transient psychoactive properties when its leaves, or e ...

''.

References

External links

* {{MeshName, Clerodane+diterpenes Diterpenes

Classification

Biosynthesis

See also

References

External links