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Pyrroline
Pyrrolines, also known under the name dihydropyrroles, are three different heterocyclic organic chemical compounds that differ in the position of the double bond. Pyrrolines are formally derived from the aromate pyrrole by hydrogenation. 1-Pyrroline is a cyclic imine, whereas 2-pyrroline and 3-pyrroline are cyclic amines. Substituted pyrrolines Notable examples of pyrrolines containing various substituents include: * 2-Acetyl-1-pyrroline, an aroma compound with a white bread-like smell * Thienamycin, a beta-lactam antibiotic * MTSL, a chemical used for certain NMR experiments * Pyrrolysine, an unusual proteinogenic amino acid * 1-Pyrroline-5-carboxylic acid, a biosynthetic metabolite * Porphyrin, consisting of two alternating pairs of pyrrol and pyrroline connected via methine (=CH-) bridges ''N''-substituted pyrrolines can be generated by ring-closing metathesis.Marcelle L. Ferguson, Daniel J. O'leary, And Robert H. Grubbs "Ring-closing Metathesis Synthesis Of N-boc-3-pyrroli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-pyrroline Chemical Structure
Pyrrolines, also known under the name dihydropyrroles, are three different heterocyclic compound, heterocyclic organic chemistry, organic chemical compounds that differ in the position of the double bond. Pyrrolines are formally derived from the aromaticity, aromate pyrrole by hydrogenation. 1-Pyrroline is a cyclic imine, whereas 2-pyrroline and 3-pyrroline are cyclic amines. Substituted pyrrolines Notable examples of pyrrolines containing various substituents include: * 2-Acetyl-1-pyrroline, an aroma compound with a white bread-like smell * Thienamycin, a beta-lactam antibiotic * MTSL, a chemical used for certain NMR experiments * Pyrrolysine, an unusual proteinogenic amino acid * 1-Pyrroline-5-carboxylic acid, a biosynthetic metabolite * Porphyrin, consisting of two alternating pairs of pyrrol and pyrroline connected via methine (=CH-) bridges ''N''-substituted pyrrolines can be generated by ring-closing metathesis.Marcelle L. Ferguson, Daniel J. O'leary, And Robert H. Grubbs " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-pyrroline Chemical Structure
Pyrrolines, also known under the name dihydropyrroles, are three different heterocyclic organic chemical compounds that differ in the position of the double bond. Pyrrolines are formally derived from the aromate pyrrole by hydrogenation. 1-Pyrroline is a cyclic imine, whereas 2-pyrroline and 3-pyrroline are cyclic amines. Substituted pyrrolines Notable examples of pyrrolines containing various substituents include: * 2-Acetyl-1-pyrroline, an aroma compound with a white bread-like smell * Thienamycin, a beta-lactam antibiotic * MTSL, a chemical used for certain NMR experiments * Pyrrolysine, an unusual proteinogenic amino acid * 1-Pyrroline-5-carboxylic acid, a biosynthetic metabolite * Porphyrin, consisting of two alternating pairs of pyrrol and pyrroline connected via methine (=CH-) bridges ''N''-substituted pyrrolines can be generated by ring-closing metathesis.Marcelle L. Ferguson, Daniel J. O'leary, And Robert H. Grubbs "Ring-closing Metathesis Synthesis Of N-boc-3-pyrroline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1-Pyrroline-5-carboxylic Acid
1-Pyrroline-5-carboxylic acid (systematic name 3,4-dihydro-2H-pyrrole-2-carboxylic acid) is a cyclic imino acid. Its conjugate base and anion is 1-pyrroline-5-carboxylate (P5C). In solution, P5C is in spontaneous equilibrium with glutamate-5-semialdhyde (GSA). The stereoisomer (''S'')-1-pyrroline-5-carboxylate (also referred to as L-P5C) is an intermediate metabolite in the biosynthesis and degradation of proline and arginine. In prokaryotic proline biosynthesis, GSA is synthesized from γ-glutamyl phosphate by the enzyme γ-glutamyl phosphate reductase. In most eukaryotes, GSA is synthesised from the amino acid glutamate by the bifunctional enzyme 1-pyrroline-5-carboxylate synthase (P5CS). The human P5CS is encoded by the ''ALDH18A1'' gene. The enzyme pyrroline-5-carboxylate reductase converts P5C into proline In proline degradation, the enzyme proline dehydrogenase produces P5C from proline, and the enzyme 1-pyrroline-5-carboxylate dehydrogenase converts GSA to glutamate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2-Acetyl-1-pyrroline
2-Acetyl-1-pyrroline (2AP) is an aroma compound and flavor that gives freshly baked bread, jasmine rice and basmati rice, the spice ''pandan'' (''Pandanus amaryllifolius''), and ''bread flowers'' (''Vallaris'' ''glabra'') their customary smell. Many observers describe the smell as similar to "hot, buttered popcorn", and it is credited for lending this odor to the scent of binturong (bearcat) urine. Fresh marking fluid (MF) and urine of the tiger (Indian, Amur or Siberian) and Indian leopard also have a strong aroma due to 2AP. 2AP and its structural homolog, 6-acetyl-2,3,4,5-tetrahydropyridine of similar smell, can be formed by Maillard reactions during heating of food such as the baking of bread dough. Both compounds have odor thresholds below 0.06 ng/ L. Structure and properties 2AP is a substituted pyrroline and a cyclic imine as well as a ketone In organic chemistry, a ketone is a functional group with the structure R–C(=O)–R', where R and R' can be a variety o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it has ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrole
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4 H4 NH. It is a colorless volatile liquid that darkens readily upon exposure to air. Substituted derivatives are also called pyrroles, e.g., ''N''-methylpyrrole, C4H4NCH3. Porphobilinogen, a trisubstituted pyrrole, is the biosynthetic precursor to many natural products such as heme. Pyrroles are components of more complex macrocycles, including the porphyrinogens and products derived therefrom, including porphyrins of heme, the chlorins, bacteriochlorins, and chlorophylls. Properties Pyrrole is a colorless volatile liquid that darkens readily upon exposure to air, and is usually purified by distillation immediately before use. Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl3, it has ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrrolysine
Pyrrolysine (symbol Pyl or O; encoded by the 'amber' stop codon UAG) is an α-amino acid that is used in the biosynthesis of proteins in some methanogenic archaea and bacteria; it is not present in humans. It contains an α-amino group (which is in the protonated – form under biological conditions), a carboxylic acid group (which is in the deprotonated –COO− form under biological conditions). Its pyrroline side-chain is similar to that of lysine in being basic and positively charged at neutral pH. Genetics Nearly all genes are translated using only 20 standard amino acid building blocks. Two unusual genetically-encoded amino acids are selenocysteine and pyrrolysine. Pyrrolysine was discovered in 2002 at the active site of methyltransferase enzyme from a methane-producing archeon, ''Methanosarcina barkeri''. This amino acid is encoded by UAG (normally a stop codon), and its synthesis and incorporation into protein is mediated via the biological machinery encoded by the ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aroma Compound
An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently volatile for transmission via the air to the olfactory system in the upper part of the nose. As examples, various fragrant fruits have diverse aroma compounds, particularly strawberries which are commercially cultivated to have appealing aromas, and contain several hundred aroma compounds. Generally, molecules meeting this specification have molecular weights of less than 310. Flavors affect both the sense of taste and smell, whereas fragrances affect only smell. Flavors tend to be naturally occurring, and the term ''fragrances'' may also apply to synthetic compounds, such as those used in cosmetics. Aroma compounds can naturally be found in various foods, such as fruits and their peels, wine, spices, floral scent, perfumes, fragrance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring-closing Metathesis
Ring-closing metathesis (RCM) is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the intramolecular metathesis of two terminal alkenes, which forms the cycloalkene as the ''E-'' or ''Z-'' isomers and volatile ethylene.Carey, F. A.; Sunburg, R. J. Reactions Involving Transition Metals. ''Advanced Organic Chemistry: Reaction and Synthesis'', 5th Ed.; Part B; Springer: New York, 2010, pp. 761-767.Monfette, S.; Fogg, D. E. (2009). "Equilibrium Ring-Closing Metathesis". ''Chem. Rev.'' 109 (8): 3783-3816. . The most commonly synthesized ring sizes are between 5-7 atoms;Deiters, A.; Martin, S. F. (2004). “Synthesis of Oxygen- and Nitrogen-Containing Heterocycles by Ring-Closing Metathesis”. ''Chem. Rev.'' 104 (5): 2199-2238. . however, reported syntheses include 45- up to 90- membered macroheterocycles.Cain, M. F.; Forrest, W. P.; Peryshkov, R. V.; Schrock, R. R. Muller, P. (2013). “Synthesis of a TREN in Whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteinogenic Amino Acid
Proteinogenic amino acids are amino acids that are incorporated biosynthetically into proteins during translation. The word "proteinogenic" means "protein creating". Throughout known life, there are 22 genetically encoded (proteinogenic) amino acids, 20 in the standard genetic code and an additional 2 ( selenocysteine and pyrrolysine) that can be incorporated by special translation mechanisms. In contrast, non-proteinogenic amino acids are amino acids that are either not incorporated into proteins (like GABA, L-DOPA, or triiodothyronine), misincorporated in place of a genetically encoded amino acid, or not produced directly and in isolation by standard cellular machinery (like hydroxyproline). The latter often results from post-translational modification of proteins. Some non-proteinogenic amino acids are incorporated into nonribosomal peptides which are synthesized by non-ribosomal peptide synthetases. Both eukaryotes and prokaryotes can incorporate selenocysteine into their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thienamycin
Thienamycin (also known as thienpenem) is one of the most potent naturally produced antibiotics known thus far, discovered in '' Streptomyces cattleya'' in 1976. Thienamycin has excellent activity against both Gram-positive and Gram-negative bacteria and is resistant to bacterial β-lactamase enzymes. Thienamycin is a zwitterion at pH 7. History In 1976, fermentation broths obtained from the soil bacterium '' Streptomyces cattleya'' were found to be active in a screen for inhibitors of peptidoglycan biosynthesis. Initial attempts to isolate the active compound proved difficult due to its chemical instability. After many attempts and extensive purification, the material was finally isolated in >90% purity, allowing for the structural elucidation of thienamycin in 1979 (Figure 1). Thienamycin was the first among the naturally occurring class of carbapenem antibiotics to be discovered and isolated. Carbapenems are similar in structure to their antibiotic “cousins” the penic ... [...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 quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
