2497-25-8Relevant academic research and scientific papers
First total synthesis of cyrmenin
Chakor, Narayan S.,Musso, Loana,Dallavalle, Sabrina
, p. 844 - 849 (2009)
A short and efficient synthesis of cyrmenin B1 an antifungal metabolite of myxobacteria Cystobacter armeniaca and Archangium gephyra, is described. The crucial steps of the synthesis included the formation of the dehydroalanine moiety from the corresponding serine acetate and the formation of the β-methoxyacrylate system via trimethylsilyldiazomethane methylation of the corresponding β-hydroxy enamide.
Stereoselective Synthesis of the Isomers of Notoincisol A: Assigment of the Absolute Configuration of this Natural Product and Biological Evaluation
Rycek, Lukas,Ticli, Vincenzo,Pyszkowski, Jakob,Latkolik, Simone,Liu, Xin,Atanasov, Atanas G.,Steinacher, Theresa,Bauer, Rudolf,Schuster, Daniela,Dirsch, Verena M.,Schnürch, Michael,Ernst, Margot,Mihovilovic, Marko D.
supporting information, p. 2419 - 2428 (2018/12/11)
The total syntheses of all stereoisomers of notoincisol A, a recently isolated natural product with potential anti-inflammatory activity, are reported. The asymmetric synthesis was conducted employing a lipase-mediated kinetic resolution, which enables easy access to all required chiral building blocks with the aim of establishing the absolute configuration of the naturally occurring isomer. This was achieved by comparison of optical properties of the isolated compound with the synthetic derivatives obtained. Moreover, an assessment of the biological activity on PPARγ (peroxisome proliferator-activated receptor gamma) as a prominent receptor related to inflammation is reported. Only the natural isomer was found to activate the PPARγ receptor, and this phenomenon could be explained based on molecular docking studies. In addition, the pharmacological profiles of the isomers were determined using the GABAA (gamma-aminobutyric acid A) ion channel receptor as a representative target for allosteric modulation related to diverse CNS activities. These compounds were found to be weak allosteric modulators of the α1β3 and α1β2γ2 receptor subtypes.
An Unsaturated Quinolone N-Oxide of Pseudomonas aeruginosa Modulates Growth and Virulence of Staphylococcus aureus
Szamosvári, Dávid,B?ttcher, Thomas
supporting information, p. 7271 - 7275 (2017/06/13)
The pathogen Pseudomonas aeruginosa produces over 50 different quinolones, 16 of which belong to the class of 2-alkyl-4-quinolone N-oxides (AQNOs) with various chain lengths and degrees of saturation. We present the first synthesis of a previously proposed unsaturated compound that is confirmed to be present in culture extracts of P. aeruginosa, and its structure is shown to be trans-Δ1-2-(non-1-enyl)-4-quinolone N-oxide. This compound is the most active agent against S. aureus, including MRSA strains, by more than one order of magnitude whereas its cis isomer is inactive. At lower concentrations, the compound induces small-colony variants of S. aureus, reduces the virulence by inhibiting hemolysis, and inhibits nitrate reductase activity under anaerobic conditions. These studies suggest that this unsaturated AQNO is one of the major agents that are used by P. aeruginosa to modulate competing bacterial species.
Dehydrogenative Synthesis of Linear α,β-Unsaturated Aldehydes with Oxygen at Room Temperature Enabled by tBuONO
Wang, Mei-Mei,Ning, Xiao-Shan,Qu, Jian-Ping,Kang, Yan-Biao
, p. 4000 - 4003 (2017/06/19)
Synthesis of linear α,β-unsaturated aldehydes via a room-temperature oxidative dehydrogenation has been realized by the cocatalysis of an organic nitrite and palladium with molecular oxygen as the sole clean oxidant. Linear α,β-unsaturated aldehydes could be efficiently prepared under aerobic catalytic conditions directly from the corresponding saturated linear aldehydes. Besides linear products, the aromatic analogy could also be smoothly achieved by the same standard method. The organic nitrite redox cocatalyst and alcohol solvent play a key role for realizing this method.
Formation of potentially toxic carbonyls during oxidation of triolein in the presence of alimentary antioxidants
Damanik, Marini,Murkovic, Michael
, p. 2031 - 2035 (2017/10/26)
Abstract: A relation between oil uptake and cancer as well as induction of hepatic inflammation was shown earlier. It is discussed that the main oil oxidation products—hydroperoxides and carbonyls—might be the reason for the mentioned diseases. In this manuscript quantitative determination of aldehydes which are formed during oxidation of triolein—as a model substance—using the Rancimat 679 is described. The oxidation of 11?g of triolein is carried out at 120?°C sparging air with a flow of 20?dm3/h for 10?h. A series of aliphatic aldehydes starting from hexanal to decanal as well as decenal was identified by LC–MS/MS and quantified as DNPH derivatives. In addition, the total amount of carbonyls was determined. Based on the calibration with hexanal, all other dominant substances were in the similar concentration range with maximum concentrations of 1.6?μmol/cm3 of hexanal, 2.3?μmol/cm3 of heptanal, 2.5?μmol/cm3 of octanal, 3.2?μmol/cm3 of nonanal, 4.0?μmol/cm3 of decanal after 6?h. The total amount of carbonyls reached a maximum after 6?h being 27?μmol/cm3 for triolein without antioxidant. The results of this investigation will be a basis for further toxicological studies on oxidized oils.
Method to oxidize alcohols selectively to aldehydes and ketones with heterogeneous supported ruthenium catalyst at room temperature in air and catalyst thereof
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Paragraph 0021; 0022, (2016/10/07)
The present invention relates to a method for selectively oxidizing alcohol by using a heterogeneous catalyst for producing aldehyde and ketone in an organic synthesis process used in the laboratory and chemical industries, and a catalytic system thereof. The method can be used as an intermediate product for synthesizing medicine, scent, fragrance, and precise chemical products, and can use a heterogeneous catalyst at room temperature in air by using the catalytic system and producing alcohol and ketone.COPYRIGHT KIPO 2016
Solvent-Free Aerobic Epoxidation of Dec-1-ene Using Gold/Graphite as a Catalyst
Gupta, Upendra Nath,Dummer, Nicholas F.,Pattisson, Samuel,Jenkins, Robert L.,Knight, David W.,Bethell, Donald,Hutchings, Graham J.
, p. 689 - 696 (2015/08/04)
The oxidation of dec-1-ene has been investigated using gold nanoparticles supported on graphite in the presence of a radical initiator (α,α-azobisisobutyronitrile) using oxygen from air as oxidant. We have investigated the influence of the reaction temperature (70-100 °C), catalyst mass and reaction time on the epoxide yield. In the absence of a radical initiator the reaction does not proceed, although auto-oxidation can occur at higher temperatures in the range studied. However, in the presence of an initiator, selective oxidation occurs and the initiator propagates the reaction through the formation of a peroxy-radical at the allylic C3 position. Graphite enhances the formation of the allylic products dec-1-en-3-ol, dec-1-en-3-one, and dec-2-en-1-ol; however, the addition of gold nanoparticles to the graphite, enhances formation of 1,2-epoxydecane. It is suggested that gold suppresses the formation of allylic products via a Russell termination. Graphical Abstract: [Figure not available: see fulltext.]
A detailed identification study on high-temperature degradation products of oleic and linoleic acid methyl esters by GC-MS and GC-FTIR
Berdeaux, Olivier,Fontagné, Stéphanie,Sémon, Etienne,Velasco, Joaquin,Sébédio, Jean Louis,Dobarganes, Carmen
experimental part, p. 338 - 347 (2012/06/29)
GC-MS and GC-FTIR were complementarily applied to identify oxidation compounds formed under frying conditions in methyl oleate and linoleate heated at 180 °C. The study was focused on the compounds that originated through hydroperoxide scission that remain attached to the glyceridic backbone in fats and oils and form part of non-volatile molecules. Twenty-one short-chain esterified compounds, consisting of 8 aldehydes, 3 methyl ketones, 4 primary alcohols, 5 alkanes and 1 furan, were identified. In addition, twenty non-esterified volatile compounds, consisting of alcohols, aldehydes and acids, were also identified as major non-esterified components. Furanoid compounds of 18 carbon atoms formed by a different route were also identified in this study. Overall, the composition of the small fraction originated from hydroperoxide scission provides a clear idea of the complexity of the new compounds formed during thermoxidation and frying.
A highly regio- and stereoselective cascade annulation of enals and benzodi(enone)s catalyzed by N-heterocyclic carbenes
Fang, Xinqiang,Jiang, Kun,Xing, Chong,Hao, Lin,Chi, Yonggui Robin
supporting information; experimental part, p. 1910 - 1913 (2011/04/16)
Three stereogenic centers in a row: The unconventional activation of enal compounds mediated by an N-heterocyclic carbene (NHC) has generated three consecutive reactive carbon centers that undergo highly regio- and stereoselective annulations with di(enone)s to generate benzotricyclic products containing multiple stereogenic centers (see scheme).
Aerobic oxidation of primary aliphatic alcohols to aldehydes catalyzed by a palladium(II) polyoxometalate catalyst
Barats, Delina,Neumann, Ronny
scheme or table, p. 293 - 298 (2010/04/28)
A hexadecyltrimethylammonium salt of a "sandwich" type polyoxometalate has been used as a ligand to attach a palladium(II) center. This Pd-POM compound was an active catalyst for the fast aerobic oxidation of alcohols. The unique property of this catalyst is its significant preference for the oxidation of primary versus secondary aliphatic alcohols. Since no kinetic isotope effect was observed for the dehydrogenation step, this may be the result of the intrinsically higher probability for oxidation of primary alcohols attenuated by steric factors as borne out by the higher reactivity of 1-octanol versus 2-ethyl-1-hexanol. The reaction is highly selective to aldehyde with little formation of carboxylic acid; autooxidation is inhibited. No base is required to activate the alcohol. The fast reactions appear to be related to the electron-acceptor nature of the polyoxometalate ligand that may also facilitate alcohol dehydrogenation in the absence of base.
