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Information about Terpenoids

Enlarge picture
Chemical structure of the terpenoid isopentenyl pyrophosphate.
The terpenoids, sometimes referred to as isoprenoids, are a large and diverse class of naturally occurring organic chemicals similar to terpenes, derived from five-carbon isoprene units assembled and modified in thousands of ways. Most are multicyclic structures which differ from one another not only in functional groups, but also in their basic carbon skeletons. These lipids can be found in all classes of living things, and are the largest group of natural products.

Plant terpenoids are extensively used for their aromatic qualities. They play a role in traditional herbal remedies and are under investigation for antibacterial, antineoplastic and other pharmaceutical effects. Terpenoids contribute to the scent of eucalyptus, the flavors of cinnamon, cloves and ginger and the color of yellow flowers. Well-known terpenoids include citral, menthol, camphor and the cannabinoids found in the Cannabis plant.

The steroids and sterols in animals are biologically produced from terpenoid precursors. Sometimes terpenoids are added to proteins, e.g. to enhance their attachment to the cell membrane; this is known as isoprenylation.

Many of these are substrates for plant Cytochrome P450.

Structure and classification

Terpenes are hydrocarbons resulting from the combination of several isoprene units. Terpenoids can be thought of as modified terpenes, where methyl groups have been moved or removed, or oxygen atoms added. (Some authors use the term "terpene" more broadly, to include the terpenoids.) Just like terpenes, the terpenoids can be classified according to the number of isoprene units used:
  • Monoterpenoids, 2 isoprene units
  • Sesquiterpenoids, 3 isoprene units
  • Diterpenoids, 4 isoprene units
  • Sesterterpenoids, 5 isoprene units
  • Triterpenoids, 6 isoprene units
  • Tetraterpenoids, 8 isoprene units
  • Polyterpenoids with a larger number of isoprene units
Terpenoids can also be classified according to the number of cyclic structures they contain.

Biosynthesis

Enlarge picture
Simplified version of the steroid synthesis pathway with the terpenoid intermediates isopentenyl pyrophosphate (IPP), dimethylallyl pyrophosphate (DMAPP), geranyl pyrophosphate (GPP) and squalene shown. Some intermediates are omitted for clarity.
There are two metabolic pathways of creating terpenoids:

Mevalonic acid pathway

Many organisms manufacture terpenoids through the HMG-CoA reductase pathway, the pathway that also produces cholesterol. The reactions take place in the cytosol. The pathway was discovered in the 1950s.

MEP/DOXP pathway

The 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate pathway (MEP/DOXP pathway), also known as non-mevalonate pathway or mevalonic acid independent pathway, takes place in the plastids of plants and apicomplexan protozoa as well as in many bacteria. It was discovered in the late 1980s.

Pyruvate and glyceraldehyde 3-phosphate are converted by DOXP synthase (Dxs) to 1-deoxy-D-xylulose 5-phosphate, and by DOXP reductase (Dxr, IspC) to 2-C-methyl-D-erythritol 4-phosphate (MEP). The subsequent three reaction steps catalyzed by 4-diphosphocytidyl-2-C-methyl-D-erythritol synthase (YgbP, IspD), 4-diphosphocytidyl-2-C-methyl-D-erythritol kinase (YchB, IspE), and 2-C-methyl-D-erythritol 2,4-cyclodiphosphate synthase (YgbB, IspF) mediate the formation of 2-C-methyl-D-erythritol 2,4-cyclopyrophosphate (MEcPP). Finally, MEcPP is converted to (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP) by HMB-PP synthase (GcpE, IspG), and HMB-PP is converted to isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) by HMB-PP reductase (LytB, IspH).

IPP and DMAPP are the end products in either pathway, and are the precursors of isoprene, monoterpenoids (10-carbon), diterpenoids (20-carbon), carotenoids (40-carbon), chlorophylls and plastoquinone-9 (45-carbon). Synthesis of all higher terpenoids proceeds via formation of geranyl pyrophosphate (GPP), farnesyl pyrophosphate (FPP), and geranylgeranyl pyrophosphate (GGPP).

Although both pathways, MVA and MEP, are mutually exclusive in most organisms, interactions between them have been reported in plants and few bacteria species.

OrganismPathways
EubacteriaMVA or MEP
ArchaeaMVA
Green AlgaeMEP
Plants MVA and MEP
Animals MVA
Fungi MVA

See also

External link

 •  • [ e]
Major families of biochemicals
Peptides | Amino acids | Nucleic acids | Carbohydrates | Lipids | Terpenes | Carotenoids | Tetrapyrroles | Enzyme cofactors | Steroids | Flavonoids | Alkaloids | Polyketides | Glycosides
Analogues of nucleic acids:Types of Terpenes and TerpenoidsAnalogues of nucleic acids:
General:
Hemiterpenoids: Isoprene | Prenol | Isovaleric acid
Monoterpenoids: Geranyl pyrophosphate | Eucalyptol | Limonene | Pinene
Sesquiterpenoids: Farnesyl pyrophosphate | Artemisinin | Bisabolol
Diterpenoids: Geranylgeranyl pyrophosphate | Retinol | Retinal | Phytol | Taxol | Forskolin | Aphidicolin
Sesterterpenoids:
Triterpenoids: Squalene | Lanosterol
Tetraterpenoids: Lycopene | Carotene
Polyterpenoids:
organic compounds]] An organic compound is any member of a large class of chemical compounds whose molecules contain carbon; for historical reasons discussed below, a few types of compounds such as carbonates, carbon oxides and cyanides, as well as elemental carbon are
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Terpenes are a large and varied class of hydrocarbons, produced primarily by a wide variety of plants, particularly conifers, though also by some insects such as swallowtail butterflies, which emit terpenes from their osmeterium.
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Isoprene is a common synonym for the chemical compound 2-methylbuta-1,3-diene. It is commonly used in industry, is an important biological material, and can be a harmful environmental pollutant and toxicant when present in excess quantities.
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In organic chemistry, functional groups (or moieties) are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules.
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Lipids can be broadly defined as any fat-soluble (hydrophobic), naturally-occurring molecules. The term is more-specifically used to refer to fatty-acids and their derivatives (including tri-, di-, and monoglycerides and phospholipids) as well as other fat-soluble sterol-containing
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Antiseptics (Greek αντί, against, and σηπτικός, putrefactive) are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction.
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Antineoplastics (or "antitumor antibiotics", or "noncovalent DNA-binding drugs", or "cytotoxic antibiotics", see also neoplastics) are drugs that inhibit and combat the development of tumors.
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A pharmaceutical company, or drug company, is a commercial business whose focus is to research, develop, market and/or distribute drugs, most commonly in the context of healthcare. They can deal in generic and/or brand medications.
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Eucalyptus
L'Hér.

natural range


Species

About 700; see the List of Eucalyptus species

Eucalyptus
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C. verum

Binomial name
Cinnamomum verum
J.Presl

Cassia ("Chinese cinnamon") is also commonly called (and sometimes sold as) cinnamon.

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S. aromaticum

Binomial name
Syzygium aromaticum
(L.) Merrill & Perry

Cloves (Syzygium aromaticum, syn.
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Citral, or 3,7-dimethyl-2,6-octadienal or lemonal, is either of a pair of terpenoids with the molecular formula C10H16O. The two compounds are double bond isomers. The trans isomer is known as geranial or citral A.
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Not to be confused with methanol.


Menthol is a covalent organic compound made synthetically or obtained from peppermint or other mint oils.
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Camphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the Camphor laurel (Cinnamomum camphora
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Cannabinoids are a group of terpenophenolic compounds present in Cannabis (Cannabis sativa L). The broader definition of cannabinoids refer to a group of substances that are structurally related to tetrahydrocannabinol (THC) or that bind to cannabinoid receptors.
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Sterols, or steroid alcohols are a subgroup of steroids with a hydroxyl group in the 3-position of the A-ring. They are amphipathic lipids synthetised from acetyl-coenzyme A. The overall molecule is quite flat. The hydroxyl group on the A ring is polar.
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Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
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Prenylation or isoprenylation or lipidation is the addition of hydrophobic molecules to a protein. It is usually assumed that prenyl groups facilitate attachment to cell membranes, similar to lipid anchor like the GPI anchor, though direct evidence is missing.
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Substrate may mean:
  • Substrate (aquarium), the material used in the bottom of an aquarium
  • Substrate (biochemistry), a molecule which is acted upon by an enzyme
  • Substrate (materials science), the material on which a process is conducted

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Cytochrome P450 (abbreviated CYP, P450, infrequently CYP450) is a very large and diverse superfamily of hemoproteins found in bacteria, archaea and eukaryotes.[1] They are so named because of their properties i.e.
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Terpenes are a large and varied class of hydrocarbons, produced primarily by a wide variety of plants, particularly conifers, though also by some insects such as swallowtail butterflies, which emit terpenes from their osmeterium.
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hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. With relation to chemical terminology, aromatic hydrocarbons or arenes, alkanes, alkenes and alkyne-based compounds composed entirely of carbon or hydrogen are referred to as "Pure" hydrocarbons, whereas
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Isoprene is a common synonym for the chemical compound 2-methylbuta-1,3-diene. It is commonly used in industry, is an important biological material, and can be a harmful environmental pollutant and toxicant when present in excess quantities.
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In chemistry, a methyl group is a hydrophobic alkyl functional group derived from methane (CH4). It has the formula -CH3 and is very often abbreviated as -Me in the structure of a molecule. This hydrocarbon unit can be found in many organic compounds.
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2, −1
(neutral oxide)
Electronegativity 3.44 (Pauling scale)
Ionization energies
(more) 1st: 1313.9 kJmol−1
2nd: 3388.3 kJmol−1
3rd: 5300.5 kJmol−1

Atomic radius 60 pm
Atomic radius (calc.
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In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell. In each pathway a principal chemical is modified by chemical reactions. These reactions are accelerated, more accurately catalyzed, by enzymes.
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