|
Enniatin
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, and they have been proposed as replacements for nonactin in specific ammonium-based electrodes. Enniatins have been also mentioned as potential anti-AIDS drugs. See also * Beauvericin * Fusafungine Fusafungine (INN), also known as fusafungin, is an active agent used in antibiotics for treatment of nasal and throat infection. It also possesses anti-inflammatory properties. Fusafungine is a mixture of enniatin cyclohexadepsipeptides made ... Biosynthesis Chemical properties References {{reflist Depsipeptides Ionophores ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionophore
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 (carrier-based ion selective electrodes) 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. Some ionophores are synthesized by microorganisms to import ions into their cells. Synthetic ion carriers have also been prepared. Ionophores selective for cations and anions have found many applications in analysis. These compounds have also shown to have various biological effects and a synergistic effect when combined with the ion they bind. Classification Biological activities of metal ion-binding compounds can be changed in response to the increment of the metal conce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beauvericin
Beauvericin is a depsipeptide with antibiotic and insecticidal effects belonging to the enniatin family. It was isolated from the fungus ''Beauveria bassiana'', but is also produced by several other fungi, including several ''Fusarium'' species; it may therefore occur in grain (such as corn, wheat and barley) contaminated with these fungi. Beauvericin is active against Gram-positive bacteria and mycobacteria, and is also capable of inducing programmed cell death in mammals. Chemically, beauvericin is a cyclic hexadepsipeptide with alternating N-methyl- phenylalanyl and D-hydroxy-iso-valeryl residues. Its ion-complexing capability allows beauvericin to transport alkaline earth metal and alkali metal ions across cell membranes. Beauvericin has ''in vitro'' fungicidal effects on ''Candida parapsilosis'' when used in combination with the antifungal drug ketoconazole at dosages of 0.1 μg/ml. Increased survivability rates and low cytotoxicity were also observed in mouse model ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Compound
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element is therefore not a compound. A compound can be transformed into a different substance by a chemical reaction, which may involve interactions with other substances. In this process, bonds between atoms may be broken and/or new bonds formed. There are four major types of compounds, distinguished by how the constituent atoms are bonded together. Molecular compounds are held together by covalent bonds; ionic compounds are held together by ionic bonds; intermetallic compounds are held together by metallic bonds; coordination complexes are held together by coordinate covalent bonds. Non-stoichiometric compounds form a disputed marginal case. A chemical formula specifies the number of atoms of each element in a compound molecule, usi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusarium
''Fusarium'' is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the soil microbial community. Some species produce mycotoxins in cereal crops that can affect human and animal health if they enter the food chain. The main toxins produced by these ''Fusarium'' species are fumonisins and trichothecenes. Despite most species apparently being harmless (some existing on the skin as commensal members of the skin flora), some ''Fusarium'' species and subspecific groups are among the most important fungal pathogens of plants and animals. The name of ''Fusarium'' comes from Latin ''fusus'', meaning a spindle. Taxonomy The taxonomy of the genus is complex. A number of different schemes have been used, and up to 1,000 species have been identified at times, with approaches varying between wide and narrow concepts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depsipeptide
A depsipeptide is a peptide in which one or more of its amide, -C(O)NHR-, groups are replaced by the corresponding ester, -C(O)OR, Many depsipeptides have both peptide and ester linkages. Elimination of the N–H group in a peptide structure results in a decrease of H-bonding capability, which is responsible for secondary structure and folding patterns of peptides, thus inducing structural deformation of the helix and b-sheet structures. Because of decreased resonance delocalization in esters relative to amides, depsipeptides have lower rotational barriers for cis-trans isomerization and therefore they have more flexible structures than their native analogs. They are mainly found in marine and microbial natural products. Depsipeptide natural products 222px, Enterochelin is a depsipeptide that is an iron-transporter. Several depsipeptides have been found to exhibit anti-cancer properties. A depsipeptide enzyme inhibitor includes romidepsin, a member of the bicyclic peptide class, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nonactin
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. Sources Nonactin is commercially available; as of 2006, these bacterial species produce nonactin: '' Streptomyces tsukubensis'', '' Streptomyces griseus'', '' Streptomyces chrysomallus'' and '' Streptomyces werraensis''. Total syntheses have been reported. Structure and properties Nonactin was isolated by Corbaz ''et al.'' in 1955 from bacterial strains. It is composed of four tetrahydrofuran rings and four esters linked by saturated aliphatic chain sections. Nonactin has a 48-member ring, built from 40 carbon and 12 (8 on the ring, 4 as ketones) o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual may not notice any symptoms, or may experience a brief period of influenza-like illness. Typically, this is followed by a prolonged incubation period with no symptoms. If the infection progresses, it interferes more with the immune system, increasing the risk of developing common infections such as tuberculosis, as well as other opportunistic infections, and tumors which are rare in people who have normal immune function. These late symptoms of infection are referred to as acquired immunodeficiency syndrome (AIDS). This stage is often also associated with unintended weight loss. HIV is spread primarily by unprotected sex (including anal and vaginal sex), contaminated blood transfusions, hypodermic needles, and from mother to ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fusafungine
Fusafungine (INN), also known as fusafungin, is an active agent used in antibiotics for treatment of nasal and throat infection. It also possesses anti-inflammatory properties. Fusafungine is a mixture of enniatin cyclohexadepsipeptides made up of alternating D-α-hydroxyvaleric acid and L-''N''-methylamino acid residues, produced by the ascomycete ''Fusarium lateritium'', and marketed by Servier under the trade names Locabiotal, Bioparox, and Locabiosol. According to a pooled analysis study done in the UK for the efficacy of fusafungine in rhinopharingitis, it was found that the proportion of patients who showed an improvement in symptoms from Day 0 to Day 4 of infection was 61.5% with fusafungine vs. 46.8% when compared to a placebo. In February 2016, the European Medicines Agency recommended the withdrawal of fusafungine from the market due to rare but severe allergic reactions (mainly bronchospasm Bronchospasm or a bronchial spasm is a sudden constriction of the muscles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Depsipeptides
A depsipeptide is a peptide in which one or more of its amide, -C(O)NHR-, groups are replaced by the corresponding ester, -C(O)OR, Many depsipeptides have both peptide and ester linkages. Elimination of the N–H group in a peptide structure results in a decrease of H-bonding capability, which is responsible for secondary structure and folding patterns of peptides, thus inducing structural deformation of the helix and b-sheet structures. Because of decreased resonance delocalization in esters relative to amides, depsipeptides have lower rotational barriers for cis-trans isomerization and therefore they have more flexible structures than their native analogs. They are mainly found in marine and microbial natural products. Depsipeptide natural products 222px, Enterochelin is a depsipeptide that is an iron-transporter. Several depsipeptides have been found to exhibit anti-cancer properties. A depsipeptide enzyme inhibitor includes romidepsin, a member of the bicyclic peptide class, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
