22348-95-4Relevant academic research and scientific papers
Determination of the Absolute Configurations and Sensory Properties of the Enantiomers of a Homologous Series (C6-C10) of 2-Mercapto-4-alkanones
Kiske, Christiane,Riegel, Anja Devenie,Hopf, Ronja,Kvindt, Anna,Poplacean, Iulia,Engel, Karl-Heinz,Taniguchi, Tohru,Swamy, Mahadeva M. M.,Monde, Kenji,Eisenreich, Wolfgang
, p. 1187 - 1196 (2019)
The enantiomers of a homologous series (C6-C10) of 2-mercapto-4-alkanones were obtained by lipase-catalyzed kinetic resolution of the corresponding racemic 2-acetylthio-4-alkanones. Their configurations were assigned via vibrational circular dichroism and 1H NMR anisotropy based methods. Odor thresholds and odor qualities were determined by capillary gas chromatography-olfactometry using chiral stationary phases. There were minima of the odor thresholds for the chain lengths C7 and C8. Except for chain length C8, the enantiomers of the other homologues showed similar odor thresholds. The odor qualities ranged from pungent (C5) to mushroom (C9 and C10) and were similar to those known for the corresponding 1-alken-3-ones with one less C atom. In contrast to their positional isomers (4-mercapto-2-alkanones), the investigated 2-mercapto-4-alkanones do not meet the requirements of a "tropical olfactophore" (i.e., compounds possessing a 1,3-oxygen-sulfur functionality and specific arrangements of the substituents).
Ruthenium catalyzes the synthesis of γ-butenolides fused with cyclohexanones
Thombal, Raju S.,Kim, Seoung-Tae,Baik, Mu-Hyun,Lee, Yong Rok
, p. 2940 - 2943 (2019)
Ruthenium(II)-catalyzed reactions of cyclic diazodicarbonyl compounds with β-ketoamides for chemo- and stereoselective construction of cyclohexanone-fused γ-butenolides are described. This study represents the first example of the addition of an enol substrate which is formed by the tautomerization of the β-ketoamides to the electrophilic carbene center for unusual cyclization through amide cleavage. The combined experimental and computational studies shed light on the mechanistic pathway favouring the unusual ring formation reaction instead of the involvement of the general carbonyl ylide intermediates for the product generation.
Synthesis of enantiopure (R)-(-)-massoialactone through ruthenium-SYNPHOS asymmetric hydrogenation
Touati, Ridha,Ratovelomanana-Vidal, Virginie,Hassine, Bechir Ben,Genet, Jean-Pierre
, p. 3400 - 3405 (2006)
Total synthesis of enantiopure (R)-(-)-massoialactone was achieved. The key step includes the asymmetric hydrogenation of an achiral β-keto ester using a ruthenium-SYNPHOS catalyst to set the hydroxyl function in a stereocontrolled manner with excellent enantioselectivity (>99% ee). Ring closing metathesis (RCM) in the presence of Grubbs' catalyst allows the final construction of the six-membered lactone.
A scaffold replacement approach towards new sirtuin 2 inhibitors
Seifert, Tina,Malo, Marcus,Kokkola, Tarja,Stéen, E. Johanna L.,Meinander, Kristian,Wallén, Erik A.A.,Jarho, Elina M.,Luthman, Kristina
, (2019/12/24)
Sirtuins (SIRT1–SIRT7) are an evolutionary conserved family of NAD+-dependent protein deacylases regulating the acylation state of ε-N-lysine residues of proteins thereby controlling key biological processes. Numerous studies have found association of the aberrant enzymatic activity of SIRTs with various diseases like diabetes, cancer and neurodegenerative disorders. Previously, we have shown that substituted 2-alkyl-chroman-4-one/chromone derivatives can serve as selective inhibitors of SIRT2 possessing an antiproliferative effect in two human cancer cell lines. In this study, we have explored the bioisosteric replacement of the chroman-4-one/chromone core structure with different less lipophilic bicyclic scaffolds to overcome problems associated to poor physiochemical properties due to a highly lipophilic substitution pattern required for achieve a good inhibitory effect. Various new derivatives based on the quinolin-4(1H)-one scaffold, bicyclic secondary sulfonamides or saccharins were synthesized and evaluated for their SIRT inhibitory effect. Among the evaluated scaffolds, the benzothiadiazine-1,1-dioxide-based compounds showed the highest SIRT2 inhibitory activity. Molecular modeling studies gave insight into the binding mode of the new scaffold-replacement analogues.
Control Mechanism for cis Double-Bond Formation by Polyunsaturated Fatty-Acid Synthases
Hayashi, Shohei,Satoh, Yasuharu,Ogasawara, Yasushi,Maruyama, Chitose,Hamano, Yoshimitsu,Ujihara, Tetsuro,Dairi, Tohru
supporting information, p. 2326 - 2330 (2019/02/01)
Polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (ARA) are essential fatty acids for humans. Some microorganisms biosynthesize these PUFAs through PUFA synthases composed of four subunits with multiple catalytic domains. These PUFA synthases each create a specific PUFA without undesirable byproducts, even though the multiple catalytic domains in each large subunit are very similar. However, the detailed biosynthetic pathways and mechanisms for controlling final-product profiles are still obscure. In this study, the FabA-type dehydratase domain (DHFabA) in the C-subunit and the polyketide synthase-type dehydratase domain (DHPKS) in the B-subunit of ARA synthase were revealed to be essential for ARA biosynthesis by in vivo gene exchange assays. Furthermore, in vitro analysis with truncated recombinant enzymes and C4- to C8-acyl ACP substrates showed that ARA and EPA synthases utilized two types of DH domains, DHPKS and DHFabA, depending on the carbon-chain length, to introduce either saturation or cis double bonds to growing acyl chains.
Isolation of the antibiotic pseudopyronine B and SAR evaluation of C3/C6 alkyl analogs
Bouthillette, Leah M.,Darcey, Catherine A.,Handy, Tess E.,Seaton, Sarah C.,Wolfe, Amanda L.
supporting information, p. 2762 - 2765 (2017/05/29)
Natural products are an abundant source of structurally diverse compounds with antibacterial activity that can be used to develop new and potent antibiotics. One such class of natural products is the pseudopyronines. Here we present the isolation of pseudopyronine B (2) from a Pseudomonas species found in garden soil in Western North Carolina, and SAR evaluation of C3 and C6 alkyl analogs of the natural product for antibacterial activity against Gram-positive and Gram-negative bacteria. We found a direct relationship between antibacterial activity and C3/C6 alkyl chain length. For inhibition of Gram-positive bacteria, alkyl chain lengths between 6 and 7 carbons were found to be the most active (IC50?=?0.04–3.8?μg/mL) whereas short alkyl chain analogs showed modest activity against Gram-negative bacteria (IC50?=?223–304?μg/mL). This demonstrates the potential for this class of natural products to be optimized for selective activity against either Gram-positive or Gram-negative bacteria.
Inversion of cpADH5 Enantiopreference and Altered Chain Length Specificity for Methyl 3-Hydroxyalkanoates
Ensari, Yunus,Dhoke, Gaurao V.,Davari, Mehdi D.,Bocola, Marco,Ruff, Anna Jo?lle,Schwaneberg, Ulrich
, p. 12636 - 12645 (2017/09/18)
Expanding the substrate scope of enzymes opens up new routes for synthesis of valuable chemicals. Ketone-functionalized fatty acid derivatives and corresponding chiral alcohols are valuable building blocks for the synthesis of a variety of chemicals including pharmaceuticals. The alcohol dehydrogenase from Candida parapsilosis (cpADH5) catalyzes the reversible oxidations of chiral alcohols and has a broad substrate range; a challenge for cpADH5 is to convert alcohols with small substituents (methyl or ethyl) next to the oxidized alcohol moiety. Molecular docking studies revealed that W286 is located in the small binding pocket and limits the access to substrates that contain aliphatic chains longer than ethyl substituent. In the current manuscript, we report that positions L119 and W286 are key residues to boost oxidation of medium chain methyl 3-hydroxy fatty acids; interestingly the enantiopreference toward methyl 3-hydroxybutyrate was inverted. Kinetic characterization of W286A showed a 5.5 fold increase of Vmax and a 9.6 fold decrease of Km values toward methyl 3-hydroxyhexanoate (Vmax: 2.48 U mg? and Km: 4.76 mm). Simultaneous saturation at positions 119 and 286 library yielded a double mutant (L119M/W286S) with more than 30-fold improved activity toward methyl 3-hydroxyoctanoate (WT: no conversion; L119M/W286S: 30 %) and inverted enantiopreference (S-enantiomer ≥99 % activity decrease and R-enantiomer >20-fold activity improvement) toward methyl 3-hydroxybutyrate.
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.
A Formal Synthesis of (-)-Perhydrohistrionicotoxin Using a Cross Metathesis-Hydrogenation Approach
Spiccia, Nicolas D.,Burnley, James,Subasinghe, Kamani,Perry, Christopher,Lefort, Laurent,Jackson, W. Roy,Robinson, Andrea J.
, p. 8725 - 8732 (2017/08/23)
The development of an efficient, high yielding six-step convergent synthesis of the semisynthetic alkaloid (-)-perhydrohistrionicotoxin is described. The key transformations include the cross metathesis of a Br?nsted-acid masked primary homoallylic amine with a vinyl cyclohexenone and a regioselective palladium catalyzed hydrogenation. This sequence generated the advanced Winterfeldt spirocyclic precursor in 47% overall yield, with a longest linear sequence of five steps.
Preparation of the even-numbered 3-oxo fatty acid nicotinyl esters from C6:0 to C18:0
Sieben, Daniela,Santana, Alexander,Nowka, Paul,Weber, Sven,Funke, Kai,Hüttenhain, Stefan H.
supporting information, p. 808 - 810 (2016/02/03)
Here, we report a systematic comparison of different methods for the transesterification of 3-oxo fatty acid alkyl esters to the corresponding nicotinyl esters. A simple method producing the target esters in high yields and purity has been developed. Nicotinyl esters are of interest for mass spectrometry analysis of fatty acids. Also, the hydrophilic head group of nicotinyl esters can be used as the basis for the preparation of liposome-building molecules.
