219126

应用筛选条件

关键词:'219126'

显示 1-20 共 20 条结果关于 "219126" 范围论文

Involvement of catalytic amino acid residues in enzyme-catalyzed polymerization for the synthesis of polyesters.

Y Suzuki et al.

Biomacromolecules, 2(2), 541-544 (2001-12-26)

Recently, a variety of aliphatic polyesters have been synthesized using hydrolases such as lipases and PHB depolymerases, and the reaction mechanism for these enzyme-catalyzed polymerization has been discussed. In this paper, we have studied the involvement of the catalytic amino

Polyhydroxybutyrate targets mammalian mitochondria and increases permeability of plasmalemmal and mitochondrial membranes.

Pia A Elustondo et al.

PloS one, 8(9), e75812-e75812 (2013-10-03)

Poly(3-hydroxybutyrate) (PHB) is a polyester of 3-hydroxybutyric acid (HB) that is ubiquitously present in all organisms. In higher eukaryotes PHB is found in the length of 10 to 100 HB units and can be present in free form as well

Yttrium complexes supported by linked bis(amide) ligand: synthesis, structure, and catalytic activity in the ring-opening polymerization of cyclic esters.

Tatyana V Mahrova et al.

Inorganic chemistry, 48(9), 4258-4266 (2009-04-28)

A series of new yttrium complexes supported by the bulky enediamido dianionic ligand DAB(2-) (DAB(2-) = (2,6-C(6)H(3)iPr(2))NC(Me)=C(Me)N(2,6-C(6)H(3)iPr(2))(2-)), that is, {DAB}Y(THF)(2)(mu-Cl)(2)Li(THF)(2) (1), {DAB}Y(OtBu)(THF)(DME) (2), and {{DAB}Y(BH(4))(2)}{Li(DME)(3)} (3), was synthesized by salt metathesis. The complexes were isolated after recrystallization in 73, 66

Variably isotactic poly(hydroxybutyrate) from racemic beta-butyrolactone: microstructure control by achiral chromium(III) salophen complexes.

Manuela Zintl et al.

Angewandte Chemie (International ed. in English), 47(18), 3458-3460 (2008-04-05)

Novel synthesis of functionalized poly(3-hydroxybutanoic acid) and its copolymers.

Z Jedliński et al.

International journal of biological macromolecules, 25(1-3), 247-253 (1999-07-23)

Novel feasibility of fuctionalized poly(3-hydroxybutanoic acid), PHB, and its copolymers synthesis via ring-opening of beta-butyrolactone (ROP) mediated by activated anionic initiators or enzymes in vitro is presented. Using these new synthetic approaches, PHB with defined chemical structure of the end

Demixing of severely overlapped ¹H NMR resonances and interpretation of anomalous intensity pattern of dipolar coupled A₃ spins in a weakly aligning medium.

Nilamoni Nath et al.

Journal of magnetic resonance (San Diego, Calif. : 1997), 207(2), 190-196 (2010-09-30)

We report a single (13)C spin edited selective proton-proton correlation experiment to decipher overcrowded (13)C coupled proton NMR spectra of weakly dipolar coupled spin systems. The experiment unravels the masked (13)C satellites in proton spectrum and permits the measurement of

Metal-catalyzed immortal ring-opening polymerization of lactones, lactides and cyclic carbonates.

Noureddine Ajellal et al.

Dalton transactions (Cambridge, England : 2003), 39(36), 8363-8376 (2010-04-29)

This Perspective article summarizes efforts paid in our group to develop efficient metal-based catalysts for the immortal ring-opening polymerization (iROP) of cyclic esters in the presence of large amounts of alcohols (ROH) as chain transfer agents. The catalyst systems reviewed

Ring-opening polymerisation of beta-butyrolactone catalysed by distannoxane complexes: study of the mechanism.

Y Hori et al.

International journal of biological macromolecules, 25(1-3), 237-245 (1999-07-23)

The mechanism of the ring-opening polymerisation of beta-butyrolactones was studied. The ring-opening polymerisation of BL catatlysed by distannoxane complexes is of a living nature. The polymerisation of racemic BL gave a predominantly syndiotactic P(3HB). The temperature effect on syndiospecificity was

Versatile catalytic systems based on complexes of zinc, magnesium and calcium supported by a bulky bis(morpholinomethyl)phenoxy ligand for the large-scale immortal ring-opening polymerisation of cyclic esters.

Valentin Poirier et al.

Dalton transactions (Cambridge, England : 2003), (44)(44), 9820-9827 (2009-11-04)

A new heteroleptic ethyl-zinc complex stabilized by a chelating bis(morpholinomethyl)phenoxy ligand has been synthesised and shown to be a highly potent initiator for the immortal ring-opening polymerisation (ROP) of lactide and beta-butyrolactone, being able to convert up to 50,000 equiv.

Basolateral amygdala cdk5 activity mediates consolidation and reconsolidation of memories for cocaine cues.

Fang-qiong Li et al.

The Journal of neuroscience : the official journal of the Society for Neuroscience, 30(31), 10351-10359 (2010-08-06)

Cocaine use and relapse involves learned associations between cocaine-associated environmental contexts and discrete stimuli and cocaine effects. Initially, these contextual and discrete cues undergo memory consolidation after being paired with cocaine exposure. During abstinence, cocaine cue memories can undergo memory

Polymerization of racemic beta-butyrolactone using supported catalysts: a simple access to isotactic polymers.

Noureddine Ajellal et al.

Chemical communications (Cambridge, England), 46(7), 1032-1034 (2010-02-04)

Grafting of [Ln(BH(4))(3)(THF)(3)] (Ln = La, Nd) onto silica affords materials containing well-identified bis(borohydride) surface species. The neodymium-decorated silica converts the beta-butyrolactone monomer into highly isotactic poly(beta-hydroxybutyrate). Under similar conditions, the molecular precursor gives rise to an atactic polymer.

Controlled ROP of β-butyrolactone simply mediated by amidine, guanidine, and phosphazene organocatalysts.

Cédric G Jaffredo et al.

Macromolecular rapid communications, 33(22), 1938-1944 (2012-08-14)

Basic organocatalysts of the guanidine (1,5,7-triazabicyclo[4.4.0]dec-5-ene, TBD), amidine (1,8-diazabicyclo[5.4.0]-undec-7-ene, DBU), and phosphazene (2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2diazaphosphorine, BEMP) type do effectively polymerize β-butyrolactone (BL). Poly(3-hydroxybutyrate)s (PHBs) with controlled molecular features, that is, controlled molar masses, narrow molar mass distributions, and well-defined functional end groups

beta-Butyrolactone.

IARC monographs on the evaluation of carcinogenic risks to humans, 71 Pt 3, 1317-1318 (1999-09-07)

Water-soluble L-alanine and related oligopeptide conjugates with poly[(R,S)-3-hydroxybutanoic acid] oligomers, synthesis and structural studies by means of electrospray ionization multistage mass spectrometry.

Z G Arkin et al.

Journal of biomaterials science. Polymer edition, 12(3), 297-305 (2001-08-04)

The reactions of (R,S) beta-butyrolactone with L-alanine and related oligopeptides (Ala-Ala-Ala) were investigated. The resulting water-soluble oligomers were composed of poly[(R,S)-3-hydroxybutanoic acid] (a-PHB) covalently conjugated to L-alanine and Ala-Ala-Ala oligopeptide. The other chain end was of the carboxylic acid type.

Synthesis of beta-lactones by the regioselective, cobalt and Lewis acid catalyzed carbonylation of simple and functionalized epoxides.

J T Lee et al.

The Journal of organic chemistry, 66(16), 5424-5426 (2001-08-04)

The PPNCo(CO)(4) and BF(3) x Et(2)O catalyzed carbonylation of simple and functionalized epoxides in DME gives the corresponding beta-lactones regioselectively in good to high yields. The carbonylation occurred selectively at the unsubstituted C-O bond of the epoxide ring, and this

Single-site beta-diiminate zinc catalysts for the ring-opening polymerization of beta-butyrolactone and beta-valerolactone to poly(3-hydroxyalkanoates).

Lee R Rieth et al.

Journal of the American Chemical Society, 124(51), 15239-15248 (2002-12-19)

Polymerization of beta-butyrolactone (BBL) and beta-valerolactone (BVL) using the zinc alkoxide initiator (BDI-1)ZnO(i)()Pr [(BDI-1) = 2-((2,6-diisopropylphenyl)amido)-4-((2,6-diisopropylphenyl)imino)-2-pentene] proceeds very rapidly under mild conditions to produce poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyvalerate) (PHV), respectively. For the monomer-to-initiator ratio 200:1, PHB number-average molecular weights (M(n))

Reactions of beta-propiolactone, beta-butyrolactone and gamma-butyrolactone with nucleic acids.

K Hemminki

Chemico-biological interactions, 34(3), 323-331 (1981-03-15)

Reactivity of beta-propiolactone, beta-butyrolactone and gamma-butyrolactone with guanosine, RNA, DNA and 4-(p-nitrobenzyl)pyridine was studied. beta-Propiolactone was 50--100 times more reactive with all the nucleophiles than beta-butyrolactone whereas gamma-butyrolactone was completely inactive. The rate of alkylation by the lactones was guanosine

Stereoelective Polymerization of β-butyrolactone.

Le Borgne A and Spassky A.

Polymer, 30(12), 2312-2319 (1989)

Highly active, productive, and syndiospecific yttrium initiators for the polymerization of racemic beta-butyrolactone.

Abderramane Amgoune et al.

Angewandte Chemie (International ed. in English), 45(17), 2782-2784 (2006-03-21)

Highly controlled immortal polymerization of β-butyrolactone by a dinuclear indium catalyst.

Cuiling Xu et al.

Chemical communications (Cambridge, England), 48(54), 6806-6808 (2012-06-07)

An ethoxy-bridged dinuclear indium catalyst was used for the ring opening polymerization of the cyclic ester β-butyrolactone to form the biodegradable polyester poly(hydroxybutyrate) (PHB). The catalyst shows remarkable activity and control during polymerization, allowing for formation of diblock polymers. Addition

1/1