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Camalexin
Camalexin (3-thiazol-2-yl-indole) is a simple indole alkaloid found in the plant ''Arabidopsis thaliana'' and other crucifers. The secondary metabolite functions as a phytoalexin to deter bacterial and fungal pathogens. Structure The base structure of camalexin consists of an indole ring derived from tryptophan. The ethanamine moiety attached to the 3 position of the indole ring is subsequently rearranged into a thiazole ring. Biosynthesis While the biosynthesis of camalexin ''in planta'' has not been fully elucidated, most of the enzymes involved in the pathway are known and involved in a metabolon complex. The pathway starts with a tryptophan precursor which is subsequently oxidized by two cytochrome P450 enzymes. The indole-3-acetaldoxime is then converted to indole-3-acetonitrile by another cytochrome P450, CYP71A13. A glutathione conjugate followed by a subsequent unknown enzyme is needed to form dihydrocamalexic acid. A final decarboxylation step by cytochrome P450 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 different compounds, it is one of the largest classes of alkaloids. Many of them possess significant physiological activity and some of them are used in medicine. The amino acid tryptophan is the biochemical precursor of indole alkaloids. History The action of some indole alkaloids has been known for ages. Aztecs used the psilocybin mushrooms which contain alkaloids psilocybin and psilocin. The flowering plant ''Rauvolfia serpentina'' which contains reserpine was a common medicine in India around 1000 BC. Africans used the roots of the perennial rainforest shrub Iboga, which contain ibogaine, as a stimulant. An infusion of Calabar bean seeds was given to people accused of crime in Nigeria: its rejection by stomach was regarded as a sign of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indole Alkaloids
Indole alkaloids are a class of alkaloids containing a Moiety (chemistry), 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 different compounds, it is one of the largest classes of alkaloids. Many of them possess significant physiological activity and some of them are used in medicine. The amino acid tryptophan is the biochemical precursor of indole alkaloids. History The action of some indole alkaloids has been known for ages. Aztecs used the psilocybin mushrooms which contain alkaloids psilocybin and psilocin. The flowering plant ''Rauvolfia serpentina'' which contains reserpine was a common medicine in India around 1000 BC. Africans used the roots of the perennial rainforest shrub Tabernanthe iboga, Iboga, which contain ibogaine, as a stimulant. An infusion of Calabar bean seeds was given to people accused of crime in Nigeria: its rejection by s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabidopsis Thaliana
''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally considered a weed. A winter annual with a relatively short lifecycle, ''A. thaliana'' is a popular model organism in plant biology and genetics. For a complex multicellular eukaryote, ''A. thaliana'' has a relatively small genome of around 135 Base pair#Length measurements, megabase pairs. It was the first plant to have its genome sequenced, and is an important tool for understanding the molecular biology of many plant traits, including flower development and phototropism, light sensing. Description ''Arabidopsis thaliana'' is an annual plant, annual (rarely biennial plant, biennial) plant, usually growing to 20–25 cm tall. The leaf, leaves form a rosette at the base of the plant, with a few leaves also on the flowering Plant ste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crucifers
Brassicaceae () or (the older but equally valid) Cruciferae () is a medium-sized and economically important family of flowering plants commonly known as the mustards, the crucifers, or the cabbage family. Most are herbaceous plants, while some are shrubs. The leaves are simple (although are sometimes deeply incised), lack stipules, and appear alternately on stems or in rosettes. The inflorescences are terminal and lack bracts. The flowers have four free sepals, four free alternating petals, two shorter free stamens and four longer free stamens. The fruit has seeds in rows, divided by a thin wall (or septum). The family contains 372 genera and 4,060 accepted species. The largest genera are ''Draba'' (440 species), ''Erysimum'' (261 species), ''Lepidium'' (234 species), ''Cardamine'' (233 species), and ''Alyssum'' (207 species). , it was divided into two subfamilies, Brassicoideae and Aethionemoideae. The family contains the cruciferous vegetables, including species such as ''Bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Metabolite
Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved in the normal cell growth, growth, Biological development, development, or reproduction of the organism. Instead, they generally mediate ecological biological interaction, interactions, which may produce a Natural selection, selective advantage for the organism by increasing its survivability or fecundity. Specific 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, flavourings, pigments, and recreational drugs. The term secondary metabolite was first coined by Albrecht Kossel, the 1910 Nobel Prize laureate for medicine and physio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phytoalexin
Phytoalexins are antimicrobial substances, some of which are antioxidative as well. They are defined not by their having any particular chemical structure or character, but by the fact that they are defensively synthesized ''de novo'' by plants that produce the compounds rapidly at sites of pathogen infection. In general phytoalexins are broad spectrum inhibitors; they are chemically diverse, and different chemical classes of compounds are characteristic of particular plant taxa. Phytoalexins tend to fall into several chemical classes, including terpenoids, glycosteroids, and alkaloids; however, the term applies to any phytochemicals that are induced by microbial infection. Function Phytoalexins are produced in plants to act as toxins to the attacking organism. They may puncture the cell wall, delay maturation, disrupt metabolism or prevent reproduction of the pathogen in question. Their importance in plant defense is indicated by an increase in susceptibility of plant tissue t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tryptophan
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromatic beta carbon substituent. Tryptophan is also a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3 (niacin). It is encoded by the codon UGG. Like other amino acids, tryptophan is a zwitterion at physiological pH where the amino group is protonated (–; pKa = 9.39) and the carboxylic acid is deprotonated ( –COO−; pKa = 2.38). Humans and many animals cannot synthesize tryptophan: they need to obtain it through their diet, making it an essential amino acid. Tryptophan is named after the digestive enzymes trypsin, which were used in its first isolation from casein proteins. It was assigned the one-letter symbol W based on the double ring being visually suggestive to the bulky letter. Function ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiazole
Thiazole (), or 1,3-thiazole, is a 5-membered heterocyclic compound that contains both sulfur and nitrogen. The term 'thiazole' also refers to a large family of derivatives. Thiazole itself is a pale yellow liquid with a pyridine-like odor and the molecular formula C3H3NS. The thiazole ring is notable as a component of the vitamin thiamine (B1). Molecular and electronic structure Thiazoles are members of the azoles, heterocycles that include imidazoles and oxazoles. Thiazole can also be considered a functional group when part of a larger molecule. Being planar thiazoles are characterized by significant pi-electron delocalization and have some degree of aromaticity, more so than the corresponding oxazoles. This aromaticity is evidenced by the 1H NMR chemical shift of the ring protons, which absorb between 7.27 and 8.77 ppm, indicating a strong diamagnetic ring current. The calculated pi-electron density marks C5 as the primary site for electrophilic substitution, and C2-H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolon
In biochemistry, a metabolon is a temporary structural-functional complex formed between sequential enzymes of a metabolic pathway, held together both by non-covalent interactions and by structural elements of the cell, such as integral membrane proteins and proteins of the cytoskeleton. The formation of metabolons allows the intermediate product from one enzyme to be passed (channelling) directly into the active site of the next consecutive enzyme of the metabolic pathway. The citric acid cycle is an example of a metabolon that facilitates substrate channeling. Another example is the dhurrin synthesis pathway in sorghum, in which the enzymes assemble as a metabolon in lipid membranes. During the functioning of metabolons, the amount of water needed to hydrate the enzymes is reduced and enzyme activity is increased. History The concept of structural-metabolic cellular complexes was first conceived in 1970 by A. M. Kuzin of the USSR Academy of Sciences, and adopted in 1972 by P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome P450
Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for example, they have not been found in ''Escherichia coli''. In mammals, these enzymes oxidize steroids, fatty acids, xenobiotics, and participate in many biosyntheses. By hydroxylation, CYP450 enzymes convert xenobiotics into hydrophilic derivatives, which are more readily excreted. P450s are, in general, the terminal oxidase enzymes in electron transfer chains, broadly categorized as P450-containing systems. The term "P450" is derived from the spectrophotometry, spectrophotometric peak at the wavelength of the absorption spectroscopy, absorption maximum of the enzyme (450 nanometre, nm) when it is in the redox, reduced state and complexed with carbon monoxide. Most P450s require a protein partner to deliver one or more electrons to reduc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are toxic metals, toxic chemicals, microbe neurotoxins, radiation particles and even specific neurotransmitters when the system is out of balance. Also some types of drugs, e.g alcohol, and some venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa'') are toxic to cells. Cell physiology Treating cells with the cytotoxic compound can result in a variety of prognoses. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death (apoptosis). Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning ''in glass'', or ''in the glass'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, known as clinical trials, and whole plants. Definition ''In vitro'' (Latin language, Latin for "in glass"; often not italicized in English usage) studies are conducted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
