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Triazole
A triazole is a heterocyclic compound featuring a five-membered ring of two carbon atoms and three nitrogen atoms with molecular formula C2H3N3. Triazoles exhibit substantial isomerism, depending on the positioning of the nitrogen atoms within the ring. Many triazoles are versatile, biologically active compounds commonly used as fungicides and plant retardants. However, triazoles are also useful in bioorthogonal chemistry, because the large number of nitrogen atoms causes triazoles to react similar to azides. Lastly, the many free lone pairs in triazoles make them useful as coordination compounds, although not typically as haptic ligands. Isomerism There are four triazole isomers, which are conventionally divided into two pairs of tautomers. In the 1,2,3-triazoles, the three nitrogen atoms are adjacent; in the 1,2,4-triazoles, an interstitial carbon separates out one nitrogen atom. Each category has two tautomers that differ by which nitrogen has a hydrogen bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2,4-Triazole
1,2,4-Triazole (as ligand in coordination compounds, Htrz abbreviation is sometimes used) is one of a pair of isomeric chemical compounds with molecular formula CHN, called triazoles, which have a five-membered ring of two carbon atoms and three nitrogen atoms. 1,2,4-Triazole and its derivatives find use in a wide variety of applications. Structure and properties 1,2,4-Triazole is a planar molecule. The C-N and N-N distances fall into a narrow range 136 - 132 picometers, consistent with the aromaticity. Although two tautomers can be envisioned, only one exists practically speaking. 1,2,4-Triazole is amphoteric, being susceptible to both N-protonation and deprotonation in aqueous solution. The pKa of 1,2,4-triazolium (C2N3H4+) is 2.45. The pKa of the neutral molecule is 10.26. Synthesis and occurrence 1,2,4-Triazoles can be prepared using the Einhorn–Brunner reaction or the Pellizzari reaction. Unsubstituted 1,2,4-triazole can be prepared from thiosemicarbazide by acylatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Click Chemistry
In chemical synthesis, click chemistry is a class of biocompatible small molecule reactions commonly used in bioconjugation, allowing the joining of substrates of choice with specific biomolecules. Click chemistry is not a single specific reaction, but describes a way of generating products that follow examples in nature, which also generates substances by joining small modular units. In many applications, click reactions join a biomolecule and a reporter molecule. Click chemistry is not limited to biological conditions: the concept of a "click" reaction has been used in chemoproteomic, pharmacological, and various biomimetic applications. However, they have been made notably useful in the detection, localization and qualification of biomolecules. Click reactions occur in one pot, are not disturbed by water, generate minimal and inoffensive byproducts, and are "spring-loaded"—characterized by a high thermodynamic driving force that drives it quickly and irreversibly to high y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voriconazole
Voriconazole, sold under the brand name Vfend among others, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, candidiasis, coccidioidomycosis, histoplasmosis, penicilliosis, and infections by '' Scedosporium'' or ''Fusarium''. It can be taken by mouth or used by injection into a vein. Common side effects include vision problems, nausea, abdominal pain, rash, headache, and seeing or hearing things that are not present. Use during pregnancy may result in harm to the baby. It is in the triazole family of medications. It works by affecting fungal metabolism and fungal cell membranes. Voriconazole was patented in 1990 and approved for medical use in the United States in 2002. It is on the World Health Organization's List of Essential Medicines. Medical uses Voriconazole is used to treat invasive aspergillosis and candidiasis and fungal infections caused by '' Scedosporium'' and ''Fusarium'' species, which may occur in immunocomp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioorthogonal Chemistry
The term bioorthogonal chemistry refers to any chemical reaction that can occur inside of living systems without interfering with native biochemical processes. The term was coined by Carolyn R. Bertozzi in 2003. Since its introduction, the concept of the bioorthogonal reaction has enabled the study of biomolecules such as glycans, proteins, and lipids in real time in living systems without cellular toxicity. A number of chemical ligation strategies have been developed that fulfill the requirements of bioorthogonality, including the 1,3-dipolar cycloaddition between azides and cyclooctynes (also termed copper-free click chemistry), between nitrones and cyclooctynes, oxime/ hydrazone formation from aldehydes and ketones, the tetrazine ligation, the isocyanide-based click reaction, and most recently, the quadricyclane ligation. The use of bioorthogonal chemistry typically proceeds in two steps. First, a cellular substrate is modified with a bioorthogonal functional group (che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isavuconazole
Isavuconazonium sulfate, sold under the brand name Cresemba, is a systemic antifungal medication of the triazole class which is used to treat invasive aspergillosis and mucormycosis. The most common side effects include abnormal liver tests, nausea, vomiting, difficulty breathing, abdominal pain, diarrhea, injection site reactions, headache, low blood potassium and skin rash. Isavuconazonium is a prodrug of isavuconazole. Medical uses Isavuconazonium is used to treat invasive aspergillosis and invasive mucormycosis in adults aged eighteen years old and older. It is available in a capsule for administration by mouth and as a powder for administration via infusion. Contraindications Isavuconazonium is contraindicated in people taking strong CYP3A4 inhibitors, strong CYP3A4 inducers, or moderate CYP3A4 or CYP3A5 inducers. It is contraindicated in people with familial short QT syndrome. Side effects Common adverse effects (occurring in between 1 and 10% of people) include l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pellizzari Reaction
The Pellizzari reaction was discovered in 1911 by Guido Pellizzari, and is the organic reaction of an amide and a hydrazide to form a 1,2,4-triazole. The product is similar to that of the Einhorn-Brunner reaction, but the mechanism itself is not regioselective. : Mechanism The mechanism begins by the nitrogen in the hydrazide attacking the carbonyl carbon on the amide to form compound 3. The negatively charged oxygen then abstracts two hydrogens from neighboring nitrogens in order for a molecule of water to be released to form compound 5. The nitrogen then performs an intramoleculer attack on the carbonyl group to form the five-membered ring of compound 6. After another proton migration from the nitrogens to the oxygen, another water molecule is released to form the 1,2,4-triazole 8. : Uses The synthesis of the 1,2,4-triazole has a wide range of biological functions. 1,2,4-triazoles have antibacterial, antifungal, antidepressant and hypoglycemic Hypoglycemia, also called low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huisgen 1,3-dipolar Cycloaddition
The azide-alkyne Huisgen cycloaddition is a 1,3-dipolar cycloaddition between an azide and a terminal or internal alkyne to give a 1,2,3-triazole. Rolf Huisgen was the first to understand the scope of this organic reaction. American chemist Karl Barry Sharpless has referred to this cycloaddition as "the cream of the crop" of click chemistry and "the premier example of a click reaction". In the reaction above azide 2 reacts neatly with alkyne 1 to afford the product triazole as a mixture of 1,4-adduct (3a) and 1,5-adduct (3b) at 98 °C in 18 hours. The standard 1,3-cycloaddition between an azide 1,3-dipole and an alkene as dipolarophile has largely been ignored due to lack of reactivity as a result of electron-poor olefins and elimination side reactions. Some success has been found with non-metal-catalyzed cycloadditions, such as the reactions using dipolarophiles that are electron-poor olefins or alkynes. Although azides are not the most reactive 1,3-dipole available f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Itraconazole
Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, blastomycosis, coccidioidomycosis, histoplasmosis, and paracoccidioidomycosis. It may be given by mouth or intravenously. Common side effects include nausea, diarrhea, abdominal pain, rash, and headache. Severe side effects may include liver problems, heart failure, Stevens–Johnson syndrome and allergic reactions including anaphylaxis. It is unclear if use during pregnancy or breastfeeding is safe. It is in the triazole family of medications. It stops fungal growth by affecting the cell membrane or affecting their metabolism. Itraconazole was patented in 1978 and approved for medical use in the United States in 1992. It is on the World Health Organization's List of Essential Medicines. Recent research works suggest itraconazole (ITZ) could also be used in the treatment of cancer by inhibiting the hedgehog pathway in a similar wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluconazole
Fluconazole is an antifungal medication used for a number of fungal infections. This includes candidiasis, blastomycosis, coccidiodomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and pityriasis versicolor. It is also used to prevent candidiasis in those who are at high risk such as following organ transplantation, low birth weight babies, and those with low blood neutrophil counts. It is given either by mouth or by injection into a vein. Common side effects include vomiting, diarrhea, rash, and increased liver enzymes. Serious side effects may include liver problems, QT prolongation, and seizures. During pregnancy it may increase the risk of miscarriage while large doses may cause birth defects. Fluconazole is in the azole antifungal family of medication. It is believed to work by affecting the fungal cellular membrane. Fluconazole was patented in 1981 and came into commercial use in 1988. It is on the World Health Organization's List of Essential Medicin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifungal Drug
An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryptococcal meningitis, and others. Such drugs are usually yes obtained by a doctor's prescription, but a few are available over the counter (OTC). Types of antifungal There are two types of antifungals: local and systemic. Local antifungals are usually administered topically or vaginally, depending on the condition being treated. Systemic antifungals are administered orally or intravenously. Of the clinically employed azole antifungals, only a handful are used systemically. These include ketoconazole, itraconazole, fluconazole, fosfluconazole, voriconazole, posaconazole, and isavuconazole. Examples of non-azole systemic antifungals include griseofulvin and terbinafine. Classes Polyenes A polyene is a molecule with multiple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pramiconazole
Pramiconazole is a triazole antifungal An antifungal medication, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis (thrush), serious systemic infections such as cryp ... which was under development by Barrier Therapeutics for the treatment of acute skin and mucosal fungal infections but was never marketed. References Dioxolanes Imidazolidinones Isopropyl compounds Lanosterol 14α-demethylase inhibitors Organofluorides Phenol ethers para-Methoxyphenylpiperazines Phenylethanolamine ethers Triazole antifungals Ureas {{Antiinfective-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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