- Synthesis of 13C-labelled cutin and suberin monomeric dicarboxylic acids of the general formula HO213C-(CH2)n-13CO2H (n = 10, 12, 14, 16, 18, 20, 22, 24, 26, 28)
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13C-labeled dicarboxylic acids HO213C-(CH2)n-13CO2H (n = 10, 12, 14, 16, 18, 20, 22, 24, 26, 28) have been synthesized as internal standards for LC-MS and GC-MS analysis of cutin and suberin monomer degradation by soil-based microorganisms. Different synthetic strategies had to be applied depending on the chain length of the respective synthetic target and because of economic considerations. 13C-labels were introduced by nucleophilic substitution of a suitable leaving group with labelled potassium cyanide and subsequent hydrolysis of the nitriles to produce the corresponding dicarboxylic acids. All new compounds are characterized by GC/MS, IR, and NMR methods as well as by elemental analysis.
- Schink, Carina,Spielvogel, Sandra,Imhof, Wolfgang
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- Cysteine-Targeted Insecticides against A. gambiae Acetylcholinesterase Are Neither Selective nor Reversible Inhibitors
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Acetylcholinesterase cysteine-targeted insecticides against malaria vector Anopheles gambia and other mosquitos have already been introduced. We have applied the olefin metathesis for the preparation of cysteine-targeted insecticides in high yields. The prepared compounds with either a succinimide or maleimide moiety were evaluated on Anopheles gambiae and human acetylcholinesterase with relatively high irreversible inhibition of both enzymes but poor selectivity. The concept of cysteine binding was not proved by several methods, and poor stability was observed of the chosen most potent/selective compounds in a water/buffer environment. Thus, our findings do not support the proposed concept of cysteine-targeted selective insecticides for the prepared series of succinimide or maleimide compounds.
- Gorecki, Lukas,Andrys, Rudolf,Schmidt, Monika,Kucera, Tomas,Psotka, Miroslav,Svobodova, Barbora,Hrabcova, Veronika,Hepnarova, Vendula,Bzonek, Petr,Jun, Daniel,Kuca, Kamil,Korabecny, Jan,Musilek, Kamil
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supporting information
p. 65 - 71
(2019/12/25)
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- Electrostatic Control of Macrocyclization Reactions within Nanospaces
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The intrinsic structural complexity of proteins makes it hard to identify the contributions of each noncovalent interaction behind the remarkable rate accelerations of enzymes. Coulombic forces are evidently primary, but despite developments in artificial nanoreactor design, a picture of the extent to which these can contribute has not been forthcoming. Here we report on two supramolecular capsules that possess structurally identical inner-spaces that differ in the electrostatic potential (EP) field that envelops them: one positive and one negative. This architecture means that only changes in the EP field influence the chemical properties of encapsulated species. We quantify these influences via acidity and rates of cyclization measurements for encapsulated guests, and we confirm the primary role of Coulombic forces with a simple mathematical model approximating the capsules as Born spheres within a continuum dielectric. These results reveal the reaction rate accelerations possible under Coulombic control and highlight important design criteria for nanoreactors.
- Wang, Kaiya,Cai, Xiaoyang,Yao, Wei,Tang, Du,Kataria, Rhea,Ashbaugh, Henry S.,Byers, Larry D,Gibb, Bruce C.
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supporting information
p. 6740 - 6747
(2019/05/06)
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- Long-chain α-ω Diols from renewable fatty acids via tandem olefin metathesis-ester hydrogenation
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Long chain α-ω diols were readily accessed from renewable fatty acid methyl esters following an orthogonal tandem self-metathesis-ester hydrogenation protocol. By adding a base and a bidentate ligand, the metathesis catalysts were transformed in situ into efficient ester hydrogenation catalysts. The selectivity of the hydrogenation reaction was tuned towards the exclusive formation of either the unsaturated or the saturated diol by modifying the ligand/catalyst ratio. An orthogonal tandem cross-metathesis-ester hydrogenation reaction was also applied for the synthesis of a fragrance compound.
- Gonzalez-De-Castro, Angela,Cosimi, Elena,Aguila, Mae Joanne B.,Gajewski, Piotr,Schmitkamp, Mike,De Vries, Johannes G.,Lefort, Laurent
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supporting information
p. 1678 - 1684
(2017/06/07)
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- ALIPHATIC MATERIALS AND USES THEREOF IN HEATING AND COOLING APPLICATIONS
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Aliphatic materials and their use in passive heating and cooling applications are generally disclosed. In some embodiments, dibasic acids and esters (diesters) thereof and their use in passive heating and cooling applications are disclosed. In some embodiments, C18 dibasic acids and esters thereof are disclosed, including their use in passive heating and cooling applications. In some embodiments, various olefins, including alkenes and olefinic acids and esters, are disclosed, including their use in passive heating and cooling applications.
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Paragraph 0110-0111
(2016/10/31)
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- Compositions and methods for binding lysophosphatidic acid
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Compositions and methods for making and using anti-LPA agents, for example, monoclonal antibodies, are described. Variable domain and complementarity determining region amino acid sequences of several monoclonal antibodies against LPA are disclosed, as is a consensus anti-LPA monoclonal antibody variable domain sequence.
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Page/Page column 61-63
(2015/11/10)
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- PH-responsive dendritic core-multishell nanocarriers
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In this paper we describe novel pH-responsive core-multishell (CMS) nanocarrier (pH-CMS), obtained by introducing an aromatic imine linker between the shell and the core. At a pH of 5 and lower the used imine linker was rapidly cleaved as demonstrated by NMR studies. The CMS nanocarriers were loaded with the dye Nile red (NR) and the anticancer drug doxorubicin (DOX), respectively. The transport capacities were determined using UV/Vis spectroscopy, and the sizes of the loaded and unloaded CMS nanocarriers were investigated using dynamic light scattering (DLS). We could show that CMS nanocarriers efficiently transported NR in supramolecular aggregates, while DOX was transported in a unimolecular fashion. After cellular uptake the DOX-loaded pH-responsive nanocarriers showed higher toxicities than the stable CMS nanocarriers. This is due to a more efficient DOX release caused by the cleavage of the pH-labile imine bond at lower pH within the intracellular compartments.
- Fleige, Emanuel,Achazi, Katharina,Schaletzki, Karolina,Triemer, Therese,Haag, Rainer
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- The anti-malarial activity of bivalent imidazolium salts
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A series of compounds containing bivalent imidazolium rings and one triazolium analog were synthesized and evaluated for their ability to inhibit the replication of Plasmodium falciparum cultures. The activity and selectivity of the compounds for P. falciparum cultures were found to depend on the presence of electron-deficient rings that were spaced an appropriate distance apart. The activity of the compounds was not critically dependent on the nature of the linker between the electron-deficient rings, an observation that suggests that the rings were responsible for the primary interaction with the molecular target of the compounds in the parasite. The bivalent imidazolium and triazolium compounds disrupted the process whereby merozoites gain entry into erythrocytes, however, they did not appear to prevent merozoites from forming. The compounds were also found to be active in a murine Plasmodium berghei infection, a result consistent with the compounds specifically interacting with a parasite component that is required for replication and is conserved between two Plasmodium species.
- Vlahakis, Jason Z.,Mitu, Simona,Roman, Gheorghe,Rodriguez, E. Patricia,Crandall, Ian E.,Szarek, Walter A.
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experimental part
p. 6525 - 6542
(2011/12/02)
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- Enantioselective total synthesis and correction of the absolute configuration of megislactone
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The title compound, one of the constituents from Iryanthera megistophylla, has been synthesized in enantiopure forms. The stereogenic centers at C-2 and C-3 were constructed by using a chiral auxiliary induced asymmetric aldolization and the C-4 was derived from the corresponding optically active lactates. The carbon-carbon double bond in the side chain was derived from a pure cis vinyl iodide using a Suzuki coupling with an alkyl borane formed in situ from the corresponding terminal alkene. A previously unknown (partial) cis to trans transformation of an isolated C-C double bond in a long alkyl chain was observed during the deprotection of TBS group with CAN. Somewhat unexpectedly, the otherwise undetectable co-presence of the trans isomer of the remote double bond in a long alkyl chain was clearly revealed in 1H and 13C NMR in the presence of a lactone ring. The present work unambiguously shows that the absolute configuration of the natural compound is the antipode of the one originally reported. Some errors in the previous 1H and 13C NMR signal assignments are also corrected.
- Ren, Guo-Bao,Wu, Yikang
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p. 4408 - 4415
(2008/09/20)
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- Dynamic assessment of bilayer thickness by varying phospholipid and hydraphile synthetic channel chain lengths
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A library of "hydraphile" synthetic ion channel analogues that differ in overall length from ~28-58 A has been prepared. A new and convenient ion-selective electrode (ISE) method was used to assay Na+ release. Liposomes were formed from three d
- Weber, Michelle E.,Schlesinger, Paul H.,Gokel, George W.
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p. 636 - 642
(2007/10/03)
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- Enantioselective synthesis of α-alkyl-β,γ-unsaturated esters through efficient Cu-catalyzed allylic alkylations
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Treatment of an (allyl)organosilane with silica gel in refluxing toluene brought about deallylation forming an Si-O-Si bond with the silicon on the silica gel. This Si-O-Si bond formation provides us with a new reliable method for the functionalization of a silica gel surface. Copyright
- Murphy, Kerry E.,Hoveyda, Amir H.
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p. 4690 - 4691
(2007/10/03)
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- Pyridinecarboxamide derivatives
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Pyridinecarboxamide derivatives of the formula STR1 (wherein n represents an integer of 14-18, and R represents a hydrogen atom or a straight or branched C1 -C4 alkyl group) or physiologically acceptable salts thereof. The compounds have excellent inhibiting activity of cerebral edema, especially ischemic cerebral edema, and inhibiting activity of delayed death of neuronal cells (an inhibiting activity of Ca-influx in neuronal cells). Cerebral edema is a pathologic condition accompanying cerebrovascular disorders, especially the acute stage of cerebrovascular disorders and then the compounds are useful as an agent for inhibiting cerebral edema or a therapeutic agent for cerebrovascular disorders. Moreover, the compounds have no hypotensive action which is considered to be side-effect in treating the acute stage cerebrovascular disorders and hardly show a behavior suppressing action so that they are an excellent therapeutic agent for, in particular, the acute stage cerebrovascular disorders. Moreover, the compounds show a cerebral protective activity (an anti-anoxic activity), an increasing activity of cerebral blood flow, and an inhibiting activity of lipid peroxidation and these activities may lead to the increased utility as a therapeutic agent for cerebrovascular disorders.
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- Bifunctional compounds from reaction of alkoxy hydroperoxides with metal salts
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Alkoxy hydroperoxides, obtained by ozonizing olefins in alcoholic solution, were treated with ferrous sulfate. C-C bond scission and radical formation was followed by dimerization of the radicals formed. Ozonides reacted similarly. Acyclic and cyclic olefins, including a cyclic enol ether, gave rise to a range of α,ω-disubstituted products in modest yields. By using ferric chloride, ω-chloro esters were obtained from the alkoxy hydroperoxides derived from olefinic esters.
- Cardinale,Laan,Van Der Steen,Ward
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p. 6051 - 6054
(2007/10/02)
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- Process for preparing olefins by metathesis of cyclic olefins with acyclic olefins
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A process for preparing esters and halides is disclosed comprising the step of reacting a cyclic olefin having the formula I STR1 wherein R1 and R4 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R2 and R3 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; and n represents a whole number from 2 to 12, with an acyclic olefin having the formula II STR2 wherein R5 represents hydrogen, methyl, ethyl or the group STR3 wherein R12 and R13 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; Y represents halogen; an acyloxy group R14 --CO--O wherein R14 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms, or an oxycarbonyl group R15 --O--CO wherein R15 represents alkyl containing 1-12 carbon atoms, phenyl or phenyl alkyl containing 7-12 carbon atoms; p represents a whole number from 1-12 except when Y is an R14 CO--O group wherein p is from 2 to 12. R6 and R7 are the same or different from each other and each represents hydrogen, methyl, or ethyl; R8 and R9 are the same or different from each other and each represents hydrogen or alkyl containing 1 to 5 carbon atoms; X represents halogen; an acyloxy group R10 --CO--O--, wherein R10 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, or an oxycarbonyl group R11 --O--CO, wherein R11 represents alkyl containing 1-12 carbon atoms, phenyl, or phenylalkyl containing 7-12 carbon atoms, m represents a whole number from 1-12 except when X is an R10 --CO--O-- group wherein m is from 2 to 12 in the presence of a catalytic composition comprising a halogen-tungsten salt and a reducing agent which is an organic tin compound.
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