- Synthesis of and vesicle formation from phosphorylcholine amphiphiles with one symmetrically branched alkyl chain.
-
Three phosphorylcholines with symmetrically branched alkyl chains (1a-c) have been synthesized.The synthesis involves three steps: (1) reaction of the alcohol (CnH(2n+1))2CHOH, (n = 6, 8, 10) with 2-chloro-1,3,2-dioxaphospholane in the presence of triethylamine; (2) oxidation of the resulting trialkyl phosphite with nitrogen dioxide and (3) ring opening of the cyclic phosphate triester by trimethylamine in acetonitrile.When suspended in water, these amphiphiles all form bilayer vesicles as revealed by electron microscopy and NMR spectroscopy.The vesicles have diameters of 300-1000 Angstroem and are stable for more than a week.
- Overmars, Franc J. J.,Engberts, Jan B. F. N.,Weringa, Wilke, D.
-
-
Read Online
- Long-Range Self-Assembly of an Electron-Deficient Hexaazatrinaphthylene with Out-of-Plane Substituents
-
The unprecedented time-dependent long-range supramol-ecular assembly of electron-deficient hexaazatrinaphthylene (HATN) core based on peripheral crowding with three out-of-plane cyclic ketals is reported. The single-crystal X-ray structure of the diethyl derivative provided detailed information as to how four molecules in a repeating unit were packed in order to avoid steric crowding of the out-of-plane cyclic ketal side chain, providing locking and fastening for stabilizing the self-assembled structure. The polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) did not instantaneously show any phase transition upon the cooling process. To our surprise, POM images showed a nucleation of spherulite up to 100 μm after 24 hour later. X-ray diffraction data further confirmed that these soft crystal formed a hexagonal-like crystal. The long-range self-assembly of the new material showed a slight red shift in the UV-vis absorption spectra and further substantiated by computational method.
- Chen, Yi-Ru,Zhang, Yong-Yun,Yeh, Ming-Che,Luo, Ying-Ting,Ong, Chi Wi
-
p. 613 - 618
(2019/12/24)
-
- TRIALKYL CATIONIC LIPIDS AND METHODS OF USE THEREOF
-
The present invention provides compositions and methods for the delivery of therapeutic agents to cells. In particular, these include novel, trialkyl, cationic lipids and nucleic acid-lipid particles that provide efficient encapsulation of nucleic acids and efficient delivery of the encapsulated nucleic acid to cells in vivo. The compositions of the present invention are highly potent, thereby allowing effective knock-down of a specific target protein at relatively low doses.
- -
-
Paragraph 0383; 0421
(2013/09/12)
-
- Indolo[3,2-b]carbazole-based alternating donor-acceptor copolymers: Synthesis, properties and photovoltaic application
-
Two new donor-acceptor (D-A) type copolymers, poly{5,11-di(1-decylundecyl) indolo[3,2-b]carbazole-3,9-diyl-alt-4,7-dithien-2-yl-2,1,3-benzothiadiazole- 5′,5″-diyl} (PIC-DTBT) and poly{5,11-di(1-decylundecyl)indolo[3,2-b] carbazole-3,9-diyl-alt-4,7-di(2,2′-bithien-5-yl)-2,1,3-benzothiadiazole- 5′,5″-diyl} (PIC-DT2BT) were synthesized. The polymers have an alternating structure consisting of a large-size fused aromatic ring, indolo[3,2-b]carbazole (IC), as the donor segment and 4,7-dithien-2-yl-2,1,3- benzothiadiazole (DTBT) or 4,7-di(2,2′-bithien-5-yl)-2,1,3- benzothiadiazole (DT2BT) as the acceptor segment. The absorption spectra and the electrochemical properties of PIC-DTBT and PIC-DT2BT indicate that these copolymers have suitable energy levels for photovoltaic application. Polymer photovoltaic devices based on blends of the copolymers and [6,6]-phenyl C 61 butyric acid methyl ester (PCBM) have a high open-circuit voltage (>0.9 V) under the illumination of AM 1.5 (100 mW cm-2). The higher power conversion efficiency (PCE) of PIC-DT2BT (2.07%) compared to that of PIC-DTBT (1.47%) suggests that DT2BT could be a promising building block for the efficient D-A type copolymers if the low solubility is overcome by the molecular design of the donor segment. The Royal Society of Chemistry 2009.
- Zhou, Erjun,Yamakawa, Shimpei,Zhang, Yue,Tajima, Keisuke,Yang, Chunhe,Hashimoto, Kazuhito
-
scheme or table
p. 7730 - 7737
(2010/06/11)
-
- Synthesis and antimicrobial activity of symmetrical two-tailed dendritic tricarboxylato amphiphiles
-
Two series of water-soluble, symmetrical two-tailed homologous dendritic amphiphiles-R2NCONHC((CH2)2COOH)3, 2(n,n), and R2CHNHCONHC((CH2)2COOH)3, 3(n,n), where R = n-CnH2n+1-were synthesized and compared to R″NHCONHC((CH2)2COOH)3, 1(n), R″ = n-CnH2n+1, to determine whether antimicrobial activity was influenced by total or individual alkyl chain lengths, and whether antimicrobial activity depends on hydrophobicity or tail topology (one or two). In a broad screen of 11 microorganisms, 2(n,n) and 3(n,n) generally displayed higher minimal inhibitory concentrations (MICs) than 1(n) against growth as measured by broth microdilution assays. Chain-length specificity was observed against Candida albicans as 1(16), 2(8,8), and 3(8,8) showed the lowest MIC in their respective series. The one case where two-tailed compounds displayed the lowest MICs-3(10,10), 15 μM; 3(11,11), 7.2 μM; and 3(12,12), 6.9 μM-was against Cryptococcus neoformans.
- Sugandhi, Eko W.,Falkinham III, Joseph O.,Gandour, Richard D.
-
p. 3842 - 3853
(2008/02/09)
-
- AN ANTIMICROBIAL AGENT
-
The present invention relates to novel thioglycosides of D-galactofuranose that have an antimicrobial action, methods for their synthesis, pharmaceutical compositions containing them and methods for the treatment of patients suffering microbial infection.
- -
-
Page/Page column 27
(2010/02/07)
-
- Limonene-derived phosphines in the cobalt-catalysed hydroformylation of alkenes
-
Cobalt complexes involved in the hydroformylation of alkenes using (4R,S)-4,8-dimethyl-2-octadecyl-2-phosphabicyclo[3.3.1]nonane (LIM-18), which consists of a mixture of two diastereomers, have been studied. Complexation to cobalt has been used to separate or enrich the enantiomers so that spectroscopic parameters can be determined for complexes of the form [Co2(CO)8-n(LIM-18)n] (n = 1 or 2) and [Co(CO)3(LIM-18)2][Co(CO)4] containing the different diastereomers. An X-ray structure of a complex of the form [Co(CO)3(LIM-18)]2 shows it to contain the (4R) isomer, but since this was isolated from a mixed solution of diastereomers, this does not definitively identify whether the (4R) or (4S) isomer is the more strongly coordinating isomer. Experimental studies backed up with molecular modelling suggest that steric and electronic effects determine which isomer reacts preferentially in coordination, protonation and methylation reactions. The (4R) isomer is the more strongly coordinating and is metallated preferentially, although the (4S) isomer is the more basic. Variable temperature and high pressure NMR studies on the acyl complex, [Co(C(O)C5H9)(CO)3(LIM-18)], suggest that product elimination may be accompanied by isomerisation to branched acyl species. Modified cobalt catalysed hydroformylation of reactions suggest that the two diastereomers of LIM-18 do not give greatly different rates or selectivities and that a long chain secondary alkyl substituent on the LIM gives lower linear selectivity and a faster rate than LIM-18. LIM-But gives a selectivity similar to that obtained using LIM-18.
- Polas, Anastasios,Wilton-Ely, James D.E.T.,Slawin, Alexandra M.Z.,Foster, Douglas F.,Steynberg, Petrus J.,Green, Michael J.,Cole-Hamilton, David J.
-
p. 4669 - 4677
(2007/10/03)
-
- TENSION SUPERFICIELLE ET MICELLISATION D'ALKYL SULFONATES DE SODIUM A DEUX CHAINES EGALES
-
Five new symetrical double tailed alkyl sodium sulfonates R(R)CH-SO3Na, each chain varying from 7 to 11 carbon atoms, have been synthesized and purified.Their solubilities in distillled water have been determined between 0 and 80 deg C.From measurement of surface tension, the curve γ = f(log C) permits the determination of the CMC and the surface excess.A linear plot of log(CMC) versus the total number of carbons have been established.The area per molecule near the CMC is the same for all the terms of the serie.The surface tension above the CMC decreases from 25.7 to 21.4 mN/m when the alkyl chain grows, from R = C7H16 to R = C11H23 at 60 deg C.In the presence of added NaCl, the area per molecule decreases to 55 +/- 5 Angstroem and the evolution of the CMC values versus salinity gives an estimation of the ionization degree of the micelles.
- Granet, Robert,Piekarski, Salomon
-
p. 131 - 136
(2007/10/02)
-
