Names | |
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IUPAC name 2-Carboxy-3-hydroxy-5-methoxy-L-phenylalanine | |
Systematic IUPAC name 2-[(2S)-2-Amino-2-carboxyethyl]-6-hydroxy-4-methoxybenzoic acid | |
Identifiers | |
3D model (JSmol) | |
ChemSpider |
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PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C11H13NO6 | |
Molar mass | 255.226 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Caramboxin (CBX) is a toxin found in star fruit (Averrhoa carambola) [1] [2] and the related bilimbi fruit ( Averrhoa bilimbi ). [3] Individuals with some types of kidney disease are susceptible to adverse neurological effects including intoxication, seizures and even death after eating star fruit [4] and bilimbi fruit. [3] In 2013, caramboxin was identified as the neurotoxin responsible for these effects. [2]
Caramboxin is a non-proteinogenic amino acid, with a chemical structure similar to the amino acid phenylalanine, but with extra hydroxyl, carboxyl and methoxy substituents, making it also a phenol, a benzoic acid, and a phenol ether. Caramboxin stimulates the glutamate receptors in neurons, being an agonist of both NMDA and AMPA glutamatergic ionotropic receptors with potent excitatory, convulsant, and neurodegenerative properties, [2] resulting in symptoms of central nervous system disorder, including mental confusion, seizures, and status epilepticus. [5]
A possible interaction between caramboxin and oxalic acid in starfruit can lead to both neurotoxic and nephrotoxic effects. [6] Consuming large amounts of starfruit or its juice on an empty stomach is not recommended, even for individuals with normal kidney function. [6] [7] As caramboxin is water soluble, intense hemodialysis has often been used to improve the outcome for patients. [6]
An enantioselective total synthesis of caramboxin was first published in 2024. It involves a catalytic phase-transfer alkylation of a glycine imine by ethyl acetoacetate. [8]
Carambola, also known as star fruit, is the fruit of Averrhoa carambola, a species of tree native to tropical Southeast Asia. The edible fruit has distinctive ridges running down its sides. When cut in cross-section, it resembles a star, giving it the name of star fruit. The entire fruit is edible, usually raw, and may be cooked or made into relishes, preserves, garnish, and juices. It is commonly consumed in Southeast Asia, South Asia, the South Pacific, Micronesia, parts of East Asia, the United States, parts of Latin America, and the Caribbean. The tree is cultivated throughout tropical areas of the world.
Neurotoxins are toxins that are destructive to nerve tissue. Neurotoxins are an extensive class of exogenous chemical neurological insults that can adversely affect function in both developing and mature nervous tissue. The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol, glutamate, nitric oxide, botulinum toxin, tetanus toxin, and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations.
Hemodialysis, also spelled haemodialysis, or simply dialysis, is a process of filtering the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinine and urea and free water from the blood when the kidneys are in a state of kidney failure. Hemodialysis is one of three renal replacement therapies. An alternative method for extracorporeal separation of blood components such as plasma or cells is apheresis.
Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on kidney function. There are various forms, and some drugs may affect kidney function in more than one way. Nephrotoxins are substances displaying nephrotoxicity.
Averrhoa bilimbi is a fruit-bearing tree of the genus Averrhoa, family Oxalidaceae. It is believed to be originally native to the Maluku Islands of Indonesia but has naturalized and is common throughout Southeast Asia. It is cultivated in parts of tropical South Asia and the Americas. It bears edible but extremely sour fruits. It is a close relative of the carambola tree.
Averrhoa carambola is a species of tree in the family Oxalidaceae native to tropical Southeast Asia; it has a number of common names, including carambola, star fruit and five-corner. It is a small tree or shrub that grows 5 to 12 m tall, with rose to red-purple flowers. The flowers are small and bell-shaped, with five petals that have whitish edges. The flowers are often produced year round under tropical conditions. The tree is cultivated in tropical and semitropical regions for its edible fruits.
Renal osteodystrophy is currently defined as an alteration of bone morphology in patients with chronic kidney disease (CKD). It is one measure of the skeletal component of the systemic disorder of chronic kidney disease-mineral and bone disorder (CKD-MBD). The term "renal osteodystrophy" was coined in 1943, 60 years after an association was identified between bone disease and kidney failure.
Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks. These shellfish are filter feeders and accumulate neurotoxins, chiefly saxitoxin, produced by microscopic algae, such as dinoflagellates, diatoms, and cyanobacteria. Dinoflagellates of the genus Alexandrium are the most numerous and widespread saxitoxin producers and are responsible for PSP blooms in subarctic, temperate, and tropical locations. The majority of toxic blooms have been caused by the morphospecies Alexandrium catenella, Alexandrium tamarense, Gonyaulax catenella and Alexandrium fundyense, which together comprise the A. tamarense species complex. In Asia, PSP is mostly associated with the occurrence of the species Pyrodinium bahamense.
β-Methylamino-L-alanine, or BMAA, is a non-proteinogenic amino acid produced by cyanobacteria. BMAA is a neurotoxin. Its potential role in various neurodegenerative disorders is the subject of scientific research.
Taipoxin is a potent myo- and neurotoxin that was isolated from the venom of the coastal taipan Oxyuranus scutellatus or also known as the common taipan. Taipoxin like many other pre-synaptic neurotoxins are phospholipase A2 (PLA2) toxins, which inhibit/complete block the release of the motor transmitter acetylcholine and lead to death by paralysis of the respiratory muscles (asphyxia). It is the most lethal neurotoxin isolated from any snake venom to date.
Birtoxin is a neurotoxin from the venom of the South African Spitting scorpion. By changing sodium channel activation, the toxin promotes spontaneous and repetitive firing much like pyrethroid insecticides do
α-Neurotoxins are a group of neurotoxic peptides found in the venom of snakes in the families Elapidae and Hydrophiidae. They can cause paralysis, respiratory failure, and death. Members of the three-finger toxin protein family, they are antagonists of post-synaptic nicotinic acetylcholine receptors (nAChRs) in the neuromuscular synapse that bind competitively and irreversibly, preventing synaptic acetylcholine (ACh) from opening the ion channel. Over 100 α-neurotoxins have been identified and sequenced.
CSTX is a name given to a group of closely related neurotoxic peptides present in the venom of the wandering spider Cupiennius salei. There are twenty types so far described for this protein group. However, some are reclassified into cupiennins group of toxin, including CSTX-3, -4, -5, and -6, because of their chemical affinity. The first thirteen were isolated and identified in 1994 by Lucia Kuhn-Nentwig, Johann Schaller, and Wolfgang Nentwig of the Zoological Institute at the University of Bern, Switzerland. The different types are most likely the products of splicing variant of the same gene. They are all L-type calcium channel blockers, and also exhibit cytolytic activity by forming an alpha-helix across the cell membrane in mammalian neurons. They also inhibit voltage-gated calcium channels in insect neurons.
κ-Bungarotoxin is a protein neurotoxin of the bungarotoxin family that is found in the venom of the many-banded krait, a snake found in Taiwan. κ-Bungarotoxin is a high affinity antagonist of nicotinic acetylcholine receptors (nAChRs), particularly of CHRNA3; it causes a post-synaptic blockade of neurotransmission. Although there is significant variability in the clinical effects of snake bites, neuromuscular paralysis and respiratory failure are associated with krait bites.
Lithium toxicity, also known as lithium overdose, is the condition of having too much lithium. Symptoms may include a tremor, increased reflexes, trouble walking, kidney problems, and an altered level of consciousness. Some symptoms may last for a year after levels return to normal. Complications may include serotonin syndrome.
Tityus obscurus, known as the Amazonian black scorpion, is a species of scorpion found in northern South America.
U7-ctenitoxin-Pn1a (or U7-CNTX-Pn1a for short) is a neurotoxin that blocks TRPV1 channels, and can exhibit analgestic effects. It is naturally found in the venom of Phoneutria nigriventer.
Delta hexatoxin Hv1 is a neurotoxic component found in the venom of the Australian funnel web spider.
Notexin is a toxin produced by the tiger snake (Notechis scutatus). It is a myotoxic and presynaptic, neurotoxic phospholipase A2 (PLA2s). These are enzymes that hydrolyze the bond between a fatty acid tail and glycerol in fatty acids on the 2-position.
Tityus stigmurus toxin 1 (Tst1) is a neurotoxin found in the venom of the Brazilian scorpion, Tityus stigmurus. It acts on voltage-gated sodium channels (Navs), altering opening and inactivation voltages, recovery from inactivation, and overall current flow.