Secondary metabolite
Encyclopedia
Secondary metabolites are organic compound
s that are not directly involved in the normal growth
, development, or reproduction of an organism. Unlike primary metabolite
s, absence of secondary metabolities does not result in immediate death, but rather in long-term impairment of the organism's survivability
, fecundity
, or aesthetics, or perhaps in no significant change at all. Secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory
and other interspecies defenses. Humans use secondary metabolites as medicines, flavorings, and recreational drugs.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
s that are not directly involved in the normal growth
Cell growth
The term cell growth is used in the contexts of cell development and cell division . When used in the context of cell division, it refers to growth of cell populations, where one cell grows and divides to produce two "daughter cells"...
, development, or reproduction of an organism. Unlike primary metabolite
Primary metabolite
A primary metabolite is a kind of metabolite that is directly involved in normal growth, development, and reproduction.Conversely, a secondary metabolite is not directly involved in those processes, but usually has an important ecological function....
s, absence of secondary metabolities does not result in immediate death, but rather in long-term impairment of the organism's survivability
Survivability
Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts.-Engineering:In engineering, survivability is the quantified ability of a system, subsystem, equipment, process, or procedure to continue to function during and after a natural...
, fecundity
Fecundity
Fecundity, derived from the word fecund, generally refers to the ability to reproduce. In demography, fecundity is the potential reproductive capacity of an individual or population. In biology, the definition is more equivalent to fertility, or the actual reproductive rate of an organism or...
, or aesthetics, or perhaps in no significant change at all. Secondary metabolites are often restricted to a narrow set of species within a phylogenetic group. Secondary metabolites often play an important role in plant defense against herbivory
Plant defense against herbivory
Plant defense against herbivory or host-plant resistance describes a range of adaptations evolved by plants which improve their survival and reproduction by reducing the impact of herbivores. Plants use several strategies to defend against damage caused by herbivores...
and other interspecies defenses. Humans use secondary metabolites as medicines, flavorings, and recreational drugs.
Categories
Most of the secondary metabolites of interest to humankind fit into categories which classify secondary metabolites based on their biosynthetic origin. Since secondary metabolites are often created by modified primary metabolite synthases, or "borrow" substrates of primary metabolite origin, these categories should not be interpreted as saying that all molecules in the category are secondary metabolites (for example the steroid category), but rather that there are secondary metabolites in these categories.Small "small molecules"
- AlkaloidAlkaloidAlkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
s (usually a small, heavily derivatized amino acid):- HyoscyamineHyoscyamineHyoscyamine is a tropane alkaloid. It is a secondary metabolite found in certain plants of the Solanaceae family, including henbane , mandrake , jimsonweed , tomato and deadly nightshade...
, present in Datura stramoniumDatura stramoniumDatura stramonium, known by the common names Jimson weed, devil's trumpet, devil's weed, thorn apple, tolguacha, Jamestown weed, stinkweed, locoweed, datura, pricklyburr, devil's cucumber, Hell's Bells, moonflower and, in South Africa, malpitte and mad seeds, is a common weed in the... - AtropineAtropineAtropine is a naturally occurring tropane alkaloid extracted from deadly nightshade , Jimson weed , mandrake and other plants of the family Solanaceae. It is a secondary metabolite of these plants and serves as a drug with a wide variety of effects...
, present in Atropa belladonna, Deadly nightshadeDeadly nightshadeAtropa belladonna or Atropa bella-donna, commonly known as Belladonna, Devil's Berries, Death Cherries or Deadly Nightshade, is a perennial herbaceous plant in the family Solanaceae, native to Europe, North Africa, and Western Asia. The foliage and berries are extremely toxic, containing tropane... - CocaineCocaineCocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
, present in Erythroxylon coca the CocaCocaCoca, Erythroxylum coca, is a plant in the family Erythroxylaceae, native to western South America. The plant plays a significant role in many traditional Andean cultures...
plant - ScopolamineScopolamineScopolamine, also known as levo-duboisine, and hyoscine, is a tropane alkaloid drug with muscarinic antagonist effects. It is among the secondary metabolites of plants from Solanaceae family of plants, such as henbane, jimson weed and Angel's Trumpets , and corkwood...
, present in the Solanaceae (nightshade) plant family - CodeineCodeineCodeine or 3-methylmorphine is an opiate used for its analgesic, antitussive, and antidiarrheal properties...
and MorphineMorphineMorphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
, present in Papaver somniferum, the opium poppyOpium poppyOpium poppy, Papaver somniferum, is the species of plant from which opium and poppy seeds are extracted. Opium is the source of many opiates, including morphine , thebaine, codeine, papaverine, and noscapine... - TetrodotoxinTetrodotoxinTetrodotoxin, also known as "tetrodox" and frequently abbreviated as TTX, sometimes colloquially referred to as "zombie powder" by those who practice Vodou, is a potent neurotoxin with no known antidote. There have been successful tests of a possible antidote in mice, but further tests must be...
, a microbial product in FuguFuguis the Japanese word for pufferfish and the dish prepared from it, normally species of genus Takifugu, Lagocephalus, or Sphoeroides, or porcupinefish of the genus Diodon. Fugu can be lethally poisonous due to its tetrodotoxin; therefore, it must be carefully prepared to remove toxic parts and to...
and some salamanders - VincristineVincristineVincristine , formally known as leurocristine, sometimes abbreviated "VCR", is a vinca alkaloid from the Catharanthus roseus , formerly Vinca rosea and hence its name. It is a mitotic inhibitor, and is used in cancer chemotherapy.-Mechanism:Tubulin is a structural protein that polymerizes to...
& VinblastineVinblastineVinblastine is an antimicrotubule drug used to treat certain kinds of cancer, including Hodgkin's lymphoma, non-small cell lung cancer, breast cancer, head and neck cancer, and testicular cancer. It is also used to treat Langerhan cell histiocytosis....
, mitotic inhibitorMitotic inhibitorA mitotic inhibitor is a drug that inhibits mitosis, or cell division. These drugs disrupt microtubules, which are structures that pull the cell apart when it divides...
s found in the Rosy Periwinkle
- Hyoscyamine
- TerpenoidTerpenoidThe terpenoids , sometimes called 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 that differ from one another not only in...
s (come from semiterpeneTerpeneTerpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...
oligomerization):- AzadirachtinAzadirachtinAzadirachtin, a chemical compound belonging to the limonoid group, is a secondary metabolite present in neem seeds. It is a highly oxidized tetranortriterpenoid which boasts a plethora of oxygen functionality, comprising an enol ether, acetal, hemiacetal, and tetra-substituted oxirane as well as a...
, (NeemNeemAzadirachta indica is a tree in the mahogany family Meliaceae. It is one of two species in the genus Azadirachta, and is native to India growing in tropical and semi-tropical regions. Its fruits and seeds are the source of neem oil...
tree) - ArtemisininArtemisininArtemisinin , also known as Qinghaosu , and its derivatives are a group of drugs that possess the most rapid action of all current drugs against falciparum malaria. Treatments containing an artemisinin derivative are now standard treatment worldwide for falciparum malaria...
, present in Artemisia annuaArtemisia annuaArtemisia annua, also known as Sweet Wormwood, Sweet Annie, Sweet Sagewort or Annual Wormwood , is a common type of wormwood that is native to temperate Asia, but naturalized throughout the world.-Characteristics:...
Chinese wormwood - tetrahydrocannabinolTetrahydrocannabinolTetrahydrocannabinol , also known as delta-9-tetrahydrocannabinol , Δ1-THC , or dronabinol, is the main chemical psychoactive substance found in the cannabis plant. It was first isolated in 1964. In pure form, it is a glassy solid when cold, and becomes viscous and sticky if warmed...
, present in CannabisCannabisCannabis is a genus of flowering plants that includes three putative species, Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These three taxa are indigenous to Central Asia, and South Asia. Cannabis has long been used for fibre , for seed and seed oils, for medicinal purposes, and as a... - SteroidSteroidA steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
s (Terpenes with a particular ring structure)- Saponins (plant steroids, often glycosylated)
- Azadirachtin
- Glycosides (heavily modified sugar molecules):
- Nojirimycin
- GlucosinolateGlucosinolateThe glucosinolates are a class of organic compounds that contain sulfur and nitrogen and are derived from glucose and an amino acid. They occur as secondary metabolites of almost all plants of the order Brassicales , but also in the genus Drypetes .-Chemistry:Glucosinolates are water-soluble...
s
- Natural phenolNatural phenolNatural phenols, bioavailable phenols, plant phenolics, low molecular weight phenols or phenoloids are a class of natural products. They are small molecules containing one or more phenolic group. These molecules are smaller in size than polyphenols, containing less than 12 phenolic groups...
s:- ResveratrolResveratrolResveratrol is a stilbenoid, a type of natural phenol, and a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi....
- Resveratrol
- PhenazinePhenazinePhenazine , also called azophenylene, dibenzo-p-diazine, dibenzopyrazine, and acridizine, is a dibenzo annulated pyrazine and the parent substance of many dyestuffs, such as the eurhodines, toluylene red, indulines and safranines.-Synthesis:A classic method for the synthesis of phenazine is the...
s:- Pyocyanin
- Phenazine-1-carboxylic acid (and derivatives)
Big "small molecules", produced by large, modular, "molecular factories"
- PolyketidePolyketidePolyketides are secondary metabolites from bacteria, fungi, plants, and animals. Polyketides are usually biosynthesized through the decarboxylative condensation of malonyl-CoA derived extender units in a similar process to fatty acid synthesis...
s:- ErythromycinErythromycinErythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
- DiscodermolideDiscodermolide-Discodermolide is a recently discovered polyketide natural product found to be a potent inhibitor of tumor cell growth. The molecule's carbon skeleton is made up of eight polypropionate and four acetate units with 13 stereocenters.-History:...
- Erythromycin
- Fatty acidFatty acidIn chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
synthase products :- FR-900848
- U-106305
- phloroglucinolPhloroglucinolPhloroglucinol is a benzenetriol. It is an organic compound that is used in the synthesis of pharmaceuticals and explosives. This molecule exists in two forms, or tautomers, 1,3,5-trihydroxybenzene, which has phenol-like, and 1,3,5-cyclohexanetrione , which has ketone-like character. These two...
s
- Nonribosomal peptideNonribosomal peptideNonribosomal peptides are a class of peptide secondary metabolites, usually produced by microorganisms like bacteria and fungi. Nonribosomal peptides are also found in higher organisms, such as nudibranchs, but are thought to be made by bacteria inside these organisms...
s:- VancomycinVancomycinVancomycin INN is a glycopeptide antibiotic used in the prophylaxis and treatment of infections caused by Gram-positive bacteria. It has traditionally been reserved as a drug of "last resort", used only after treatment with other antibiotics had failed, although the emergence of...
- ThiostreptonThiostreptonThiostrepton is a natural cyclic oligopeptide antibiotic, derived from several strains of strepromycetes, such as Streptomyces azureus and Streptomyces laurentii.- History :...
- RamoplaninRamoplaninRamoplanin is a glycolipodepsipeptide antibiotic drug derived from strain ATCC 33076 of Actinoplanes.-Mechanism:It exerts its bacteriocidal effect by inhibiting cell wall biosynthesis, acting by inhibiting the transglycosylation step of peptidoglycan synthesis.-Uses:Its development has been...
- TeicoplaninTeicoplaninTeicoplanin is an antibiotic used in the prophylaxis and treatment of serious infections caused by Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and Enterococcus faecalis. It is a glycopeptide antibiotic extracted from Actinoplanes teichomyceticus, with a similar...
- GramicidinGramicidinGramicidin is a heterogeneous mixture of six antibiotic compounds, gramicidins A, B and C, making up 80%, 6%,and 14% respectively, all of which are obtained from the soil bacterial species Bacillus brevis and called collectively gramicidin D. Gramicidin D are linear pentadecapeptides; that is...
- BacitracinBacitracinBacitracin is a mixture of related cyclic polypeptides produced by organisms of the licheniformis group of Bacillus subtilis var Tracy, isolation of which was first reported in 1945....
- Vancomycin
- Hybrids of the above three:
- EpothiloneEpothiloneThe epothilones are a new class of cancer drugs. Like taxanes, they prevent cancer cells from dividing by interfering with tubulin, but in early trials epithilones have better efficacy and milder adverse effects than taxanes....
- Epothilone
- PolyphenolPolyphenolPolyphenols are a structural class of natural, synthetic, and semisynthetic organic chemicals characterized by the presence of large multiples of phenol structural units...
s
Non-"small molecules" - DNA, RNA, ribosome, or polysaccharide "classical" biopolymers
- Ribosomal peptidesRibosomeA ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....
:- Microcin-J25
See also
- Secondary metabolismSecondary metabolismSecondary metabolism is a term for pathways and small molecule products of metabolism that are not absolutely required for the survival of the organism. Examples of the products include antibiotics and pigments. To distinguish non-secondary metabolism, the term basic metabolism is sometimes used...
- Hairy root cultureHairy root cultureHairy root culture, also called transformed root culture, is a type of plant tissue culture that is used to study plant metabolic processes or to produce valuable secondary metabolites, often with plant genetic engineering....
, a strategy used in plant tissue culture to produce good quantities of valuable secondary metabolites