- Anchor dependency for non-glycerol based cationic lipofectins: Mixed bag of regular and anomalous transfection profiles
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Although detailed structure-activity, physicochemical and biophysical investigations in probing the anchor influence in liposomal gene delivery have been reported for glycerol-based transfection lipids, the corresponding investigation for non-glycerol based simple monocationic transfection lipids have not yet been undertaken. Towards this end, herein, we delineate our structure-activity and physicochemical approach in deciphering the anchor dependency in liposomal gene delivery using fifteen new structural analogues (lipids 1-15) of recently reported non-glycerol based monocationic transfection lipids. The C14 analogues in both series 1 (lipids 1-6) and series 2 (lipids 7-15) showed maximum efficiency in transfecting COS-1 and CHO cells. However, the C12 analogue of the ether series (lipid 3) exhibited a seemingly anomalous behavior compared with its transfection efficient C10 and C14 analogues (lipids 2 and 4) in being completely inefficient to transfect both COS-1 and CHO cells. The present structure-activity investigation also convincingly demonstrates that enhancement of transfection efficiencies through incorporation of membrane re-organizing unsaturation elements in the hydrophobic anchor of cationic lipids is not universal but cell dependent. The strength of the interaction of lipids 1-15 with DNA was assessed by their ability to exclude ethidium bromide bound to the DNA. Cationic lipids with long hydrophobic tails were found, in general, to be efficient in excluding EtBr from DNA. Gel to liquid crystalline transition temperatures of the lipids was measured by fluorescence anisotropy measurement technique. In general (lipid 2 being an exception), transfection efficient lipids were found to have their mid transition temperatures at or below physiological temperatures (37°C).
- Singh, Rajkumar Sunil,Mukherjee, Koushik,Banerjee, Rajkumar,Chaudhuri, Arabinda,Hait, Samik Kumar,Moulik, Satya Priya,Ramadas, Yerramsetti,Vijayalakshmi, Amash,Rao, Nalam Madhusudhana
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Read Online
- β-Carotene: A green, inexpensive, and convenient solvatochromic probe for the determination of solvent polarizability
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Solvent polarizability has been previously determined by using the solvatochromic probe 3,20-di-tert-butyl-2,2,21,21-tetramethyl-3,5,7,9,11,13,15, 17,19-docosanonaene whose synthesis involves 15 steps. We show here that the natural dye β-carotene, 1,1′-(3,7,12,16-tetramethyl-1,3,5,7,9,11,13, 15,17-octadecanonaene-1,18-diyl)bis[2,6,6-trimethylcyclohexene], can be conveniently employed for the accurate determination of the same solvent property. This conclusion is based on both theoretical calculations and experimental data. The former includes free energies of solvation, and the wavenumber of the longest wavelength (i.e., the solvatochromic) transition. Both quantities for β-carotene correlate linearly with the corresponding values of the docosanonaene, with slopes and correlation coefficients of practically unity. The plot of experimentally calculated solvent polarizability of β-carotene versus that of the docosanonaene was found to be linear for 68 solvents. Previously unknown solvent polarizability values are reported for eight ROCH2CH2OH (R = C1 to C10) and four 1-allyl-3-R-imidazolium chloride ionic liquids (R = C6 to C10). The dependence of solvent polarizability on the number of carbon atoms in the hydrocarbon chains of several classes of solvents is calculated, it shows the importance of van der Waals interactions in ionic liquids.
- Loffredo, Carina,Pires, Paulo Augusto R.,Imran, Muhammad,El Seoud, Omar A.
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Read Online
- METHOD FOR PRODUCING FAT ALCOHOL ETHOXYLATES
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The invention relates to a process for preparing fatty alcohol ethoxylates. According to the invention, the fatty alcohol ethoxylates are not obtained by means of the reaction of the fatty alcohols with ethylene oxide, as known from the prior art, but rat
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Page/Page column 5-8
(2020/01/11)
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- METHOD FOR PREPARING GLYCEROL ETHER AND GLYCOL ETHER
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The present invention concerns a method for preparing glycerol ether or glycol ether comprising the reaction of a compound of formula (II) with a compound of formula (III) in the presence of a heterogeneous acid catalyst of formulas (II) and (III).
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Paragraph 0082
(2015/03/28)
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- Highly efficient stereoselective catalytic C(sp3)-H insertions with donor rhodium carbenoids generated from cyclopropenes
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Rings of five and six: Donor alkenyl rhodium carbenoids generated from 3,3-dimethylcyclopropenylcarbinols exhibit high reactivity in intramolecular C-H insertions. The reactions proceed under remarkably mild conditions, tolerate the presence of the free hydroxy group, and afford an efficient and stereoselective access to a variety of functionalized carbocycles and oxygen heterocycles. Copyright
- Archambeau, Alexis,Miege, Frederic,Meyer, Christophe,Cossy, Janine
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supporting information
p. 11540 - 11544
(2013/01/15)
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- Oxidative degradation of oligo(ethylene glycol)-terminated monolayers
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The observation that oligo(ethylene glycol) (OEG)-terminated monolayers remained highly protein-resistant for a month at 37 °C in PBS buffer while they degraded faster in air can be rationalized by a proposed mechanism formulated from a model study using
- Qin, Guoting,Cai, Chengzhi
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supporting information; experimental part
p. 5112 - 5114
(2009/12/08)
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- Combinatorial synthesis of PEG oligomer libraries
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A simple chain-extending approach was established for the scale-up of the monoprotected monodisperse PEG diol materials. Reactions of THP-(OCH2CH2)n—OMs (n=4, 8, 12) with a large excess of commercially available H—(OCH2CH2)n—OH (n=1-4) under basic conditions led to THP-(OCH2CH2)n—OH (n=5-15). Similarly, Me-(OCH2CH2)n—OH (n=4-11, 13) were prepared from Me-(OCH2CH2)n—OMs (n=3, 7, 11). For the chain elongation steps, 40-80% yields were achieved through extraction purification. PEG oligomer libraries I and II were generated in 50-95% overall yields by alkylation or acylation of THP-(OCH2CH2)n—OH (n=1-15) followed by deprotection. Alkylation of Me-(OCH2CH2)n—OH (n=1-11, 13) with X—(CH2)m—CO2R (X=Br or OMs) and subsequent hydrolysis led to PEG oligomer library III in 30-60% overall yields. Combinatorial purification techniques were adapted to the larger-scale library synthesis. A total of 498 compounds, each with a weight of 2-5 g and a minimum purity of 90%, were synthesized.
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Page/Page column 9
(2010/02/15)
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- Synthesis and antiproliferative activity of alkylphosphocholines
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Alkylphosphocholines (APC) with one or more methylene groups in the alkyl chain replaced by oxygen atoms or carbonyl groups, or both have been assembled modularly using ω-diols as central building blocks. Out of 25 new compounds of this kind, 11 were evaluated for their antiproliferative activity on four cell lines and compared with miltefosine to evaluate their hemolytic activity (HA) and cytotoxicity on non-tumoral cells (MT2), used as markers of adverse effects. Compound 13 was more active on cancer cell lines than on non-tumoral cells and the data were similar for MTT and thymidine incorporation assays. It had less HA than miltefosine. Compound 13 could therefore be a candidate for the preparation of compounds with higher cytotoxicity on cancer cells and lower general toxicity.
- Agresta, Mandy,D'Arrigo, Paola,Fasoli, Ezio,Losi, Daniele,Pedrocchi-Fantoni, Giuseppe,Riva, Simona,Servi, Stefano,Tessaro, Davide
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p. 201 - 210
(2007/10/03)
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- Allylation Using Allylborates
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A study has been carried out on the scope of allylation of a range of acetals activated by trimethylsilyl trifluoromethanesulfonate (TMSOTf) using a number of organoborates.Intermolecular allylation of acyclic acetals proceeds smoothly and in high yield using lithium n-butyltriallylborate or lithium methyltriallylborate in THF at -78 deg C while 1,3-dioxanes and dioxolanes give rise to some reduction products.Intramolecular allylation may be carried out via anchoring the triallylborane using an alkoxide anion.Mechanistic studies indicate that allyl transfer is from boron and not silicon, while stereoselectivity studies on the crotylation of acyclic acetals as well as the allylation of chiral acetals derived from (2R,4R)-pentanediol indicate moderate levels of diastereoselection.
- Hunter, Roger,Michael, Joseph P.,Tomlinson, Geoffrey D.
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p. 871 - 888
(2007/10/02)
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