Enniatins are a class of organic chemical compounds found in Fusarium fungi. They appear in nature as mixtures of cyclic depsipeptides. The main variants are enniatin A, A1, B and B1 together with minor amounts of enniatin C, D, E and F.
The enniatins act as ionophores that bind ammonium, [1] and they have been proposed as replacements for nonactin in specific ammonium-based electrodes.
Enniatins have been also mentioned as potential anti-AIDS drugs.[ citation needed ]
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Ammonia is an inorganic compound of nitrogen and hydrogen with the formula NH3. A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and diammonium phosphate. Ammonia in pure form is also applied directly into the soil.
Urea, also called carbamide, is an organic compound with chemical formula CO(NH2)2. This amide has two amino groups joined by a carbonyl functional group. It is thus the simplest amide of carbamic acid.
ANFO ( AN-foh) (or AN/FO, for ammonium nitrate/fuel oil) is a widely used bulk industrial explosive. It consists of 94% porous prilled ammonium nitrate (NH4NO3) (AN), which acts as the oxidizing agent and absorbent for the fuel, and 6% number 2 fuel oil (FO). The use of ANFO originated in the 1950s.
Ammonium chloride is an inorganic compound with the formula NH4Cl and a white crystalline salt that is highly soluble in water. Solutions of ammonium chloride are mildly acidic. In its naturally occurring mineralogic form, it is known as sal ammoniac. The mineral is commonly formed on burning coal dumps from condensation of coal-derived gases. It is also found around some types of volcanic vents. It is mainly used as fertilizer and a flavouring agent in some types of liquorice. It is the product from the reaction of hydrochloric acid and ammonia.
Nonactin is a member of a family of naturally occurring cyclic ionophores known as the macrotetrolide antibiotics. The other members of this homologous family are monactin, dinactin, trinactin and tetranactin which are all neutral ionophoric substances and higher homologs of nonactin. Collectively, this class is known as the nactins. Nonactin is soluble in methanol, dichloromethane, ethyl acetate and DMSO, but insoluble in water.
Tetraethylammonium (TEA) is a quaternary ammonium cation with the chemical formula [Et4N]+, consisting of four ethyl groups attached to a central nitrogen atom. It is a counterion used in the research laboratory to prepare lipophilic salts of inorganic anions. It is used similarly to tetrabutylammonium, the difference being that its salts are less lipophilic, more easily crystallized and more toxic.
In organic chemistry, quaternary ammonium cations, also known as quats, are positively-charged polyatomic ions of the structure [NR4]+, where R is an alkyl group, an aryl group or organyl group. Unlike the ammonium ion and the primary, secondary, or tertiary ammonium cations, the quaternary ammonium cations are permanently charged, independent of the pH of their solution. Quaternary ammonium salts or quaternary ammonium compounds are salts of quaternary ammonium cations. Polyquats are a variety of engineered polymer forms which provide multiple quat molecules within a larger molecule.
Dysprosium(III) chloride (DyCl3), also known as dysprosium trichloride, is a compound of dysprosium and chlorine. It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexahydrate, DyCl3·6H2O. Simple rapid heating of the hydrate causes partial hydrolysis to an oxychloride, DyOCl.
Potassium selective electrodes are a type of ion selective electrode used in biochemical and biophysical research, where measurements of potassium concentration in an aqueous solution are required, usually on a real time basis.
In chemistry, an ionophore is a chemical species that reversibly binds ions. Many ionophores are lipid-soluble entities that transport ions across the cell membrane. Ionophores catalyze ion transport across hydrophobic membranes, such as liquid polymeric membranes or lipid bilayers found in the living cells or synthetic vesicles (liposomes). Structurally, an ionophore contains a hydrophilic center and a hydrophobic portion that interacts with the membrane.
Iridium(III) chloride is the inorganic compound with the formula IrCl3. The anhydrous compound is relatively rare, but the related hydrate is much more commonly encountered. The anhydrous salt has two polymorphs, α and β, which are brown and red colored respectively. More commonly encountered is the hygroscopic dark green trihydrate IrCl3(H2O)3 which is a common starting point for iridium chemistry.
Ammonium bifluoride is the inorganic compound with the formula [NH4][HF2] or [NH4]F·HF. It is produced from ammonia and hydrogen fluoride. This colourless salt is a glass-etchant and an intermediate in a once-contemplated route to hydrofluoric acid.
Ytterbium(III) chloride (YbCl3) is an inorganic chemical compound. It reacts with NiCl2 to form a very effective catalyst for the reductive dehalogenation of aryl halides. It is poisonous if injected, and mildly toxic by ingestion. It is an experimental teratogen, known to irritate the skin and eyes.
Lanthanum chloride is the inorganic compound with the formula LaCl3. It is a common salt of lanthanum which is mainly used in research. It is a white solid that is highly soluble in water and alcohols.
Ammonium dichromate is an inorganic compound with the formula (NH4)2Cr2O7. In this compound, as in all chromates and dichromates, chromium is in a +6 oxidation state, commonly known as hexavalent chromium. It is a salt consisting of ammonium ions and dichromate ions.
Pyrrolidine dithiocarbamate (PDTC) are a family of closely related drugs used for a metal chelation, induction of G1 phase cell cycle arrest, and preventing induction of nitric oxide synthase.
Ammonium fluorosilicate (also known as ammonium hexafluorosilicate, ammonium fluosilicate or ammonium silicofluoride) has the formula (NH4)2SiF6. It is a toxic chemical, like all salts of fluorosilicic acid. It is made of white crystals, which have at least three polymorphs and appears in nature as rare minerals cryptohalite or bararite.
Ammonium hexafluoroaluminate is an inorganic compound with the chemical formula of (NH4)3[AlF6]. It is a white solid. Upon heating, it converts to aluminium trifluoride, a reaction that releases hydrogen fluoride. It has also been used as a precursor to zeolites.
Globozoospermia is a rare and severe form of monomorphic teratozoospermia. This means that the spermatozoa show the same abnormality, and over 85% of spermatozoa in sperm have this abnormality. Globozoospermia is responsible for less than 0.1% of male infertility. It is characterised by round-headed spermatozoa without acrosomes, an abnormal nuclear membrane and midpiece defects. Affected males therefore suffer from either reduced fertility or infertility. Studies suggest that globozoospermia can be either total or partial, however it is unclear whether these two forms are variations on the same syndrome, or actually different syndromes.
Vanadium(II) sulfate describes a family of inorganic compounds with the formula VSO4(H2O)x where 0 ≤ x ≤ 7. The hexahydrate is most commonly encountered. It is a violet solid that dissolves in water to give air-sensitive solutions of the aquo complex. The salt is isomorphous with [Mg(H2O)6]SO4. Compared to the V–O bond length of 191 pm in [V(H2O)6]3+, the V–O distance is 212 pm in the [V(H2O)6]SO4. This nearly 10% elongation reflects the effect of the lower charge, hence weakened electrostatic attraction.