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Fabio Galeotti et al.
Journal of chromatography. A, 1284, 141-147 (2013-03-05)
In this study, by using tetrabutylammonium bisulfate as ion-pairing reagent, we were able to separate all the main heparin/heparan sulfate disaccharides generated by the action of heparinases along with the main Hep tetrasaccharide possessing a 3-O-sulfate group on the sulfoglucosamine
Erbo Shi et al.
Organic letters, 14(13), 3384-3387 (2012-06-27)
A metal-free C-H oxidation for the construction of allylic esters has been developed. The use of a commercially available and inexpensive catalyst and oxidant, and readily available starting materials, coupled with the operational simplicity of the reaction, renders the methodology
A J Chinchalikar et al.
The European physical journal. E, Soft matter, 35(7), 55-55 (2012-07-06)
Clouding is studied by small-angle neutron scattering (SANS) on a charged micellar system of sodium dodecyl sulphate (SDS) and tetrabutylammonium bromide (TBAB) with varying temperature and salt NaCl. We show that the clouding occurs as a result of increase in
Muhammet Uyanik et al.
Molecules (Basel, Switzerland), 17(7), 8604-8616 (2012-07-20)
We have developed the first example of hypervalent iodine(V)-catalyzed regioselective oxidation of phenols to o-quinones. Various phenols could be oxidized to the corresponding o-quinones in good to excellent yields using catalytic amounts of sodium salts of 2-iodobenzenesulfonic acids (pre-IBSes) and
R Bryan Sears et al.
Journal of inorganic biochemistry, 121, 77-87 (2013-01-29)
The complex cis-[Ru(phpy)(phen)(CH3CN)2](+) (phpy=2-phenylpyridine, phen=1,10-phenanthroline) was investigated as a potential photodynamic therapy (PDT) agent. This complex presents desirable photochemical characteristics including a low energy absorption tail extending into the PDT window (600-850nm) and photoinduced exchange of the CH3CN ligands, generating
Hongzhuo Liu et al.
Drug development and industrial pharmacy, 40(7), 896-903 (2013-05-02)
A convenient and efficient in vitro diffusion cell method to evaluate formulations for inner ear delivery via the intratympanic route is currently not available. The existing in vitro diffusion cell systems commonly used to evaluate drug formulations do not resemble
Suresh Dharuman et al.
The Journal of organic chemistry, 78(17), 8442-8450 (2013-08-13)
A reagent system comprising tetrabutylammonium nitrate-trifluoroacetic anhydride-triethylamine has been developed for the synthesis of 2-nitroglycals from various protected glycals. The base-catalyzed Ferrier rearrangement on tri-O-acetylated 2-nitroglycals has been reported for the first time. Reactivity of these nitroacetates and associated selectivity
Ying-Chieh Wong et al.
Organic letters, 14(23), 6024-6027 (2012-11-30)
The radical cascade protocol of the α-cyano α-TMS/aryl-capped alkynyl aryl ketones promoted by tert-butyl hydroperoxide under catalysis with tetrabutylammonium iodide in refluxing benzene has been developed, leading to the construction of a variety of highly functionalized [6,6,5] tricyclic frameworks in
Pieter van Dillewijn et al.
Applied and environmental microbiology, 74(21), 6820-6823 (2008-09-16)
Homogenous preparations of XenB of Pseudomonas putida, pentaerythritol tetranitrate reductase of Enterobacter cloacae, and N-ethylmaleimide reductase of Escherichia coli, all type II hydride transferases of the Old Yellow Enzyme family of flavoproteins, are shown to reduce the polynitroaromatic compound 2,4,6-trinitrotoluene
Oliver Bixner et al.
The Journal of chemical physics, 136(20), 204503-204503 (2012-06-07)
The interaction of exciton and charge transfer (CT) states plays a central role in photo-induced CT processes in chemistry, biology, and physics. In this work, we use a combination of two-dimensional electronic spectroscopy (2D-ES), pump-probe measurements, and quantum chemistry to
Ana M Brokate-Llanos et al.
Genetics, 198(4), 1559-1569 (2014-10-10)
Type III galactosemia is a metabolic disorder caused by reduced activity of UDP-galactose-4-epimerase, which participates in galactose metabolism and the generation of various UDP-sugar species. We characterized gale-1 in Caenorhabditis elegans and found that a complete loss-of-function mutation is lethal
Mei Shen et al.
Journal of the American Chemical Society, 134(24), 9856-9859 (2012-06-05)
Here we report on the unprecedentedly high resolution imaging of ion transport through single nanopores by scanning electrochemical microscopy (SECM). The quantitative SECM image of single nanopores allows for the determination of their structural properties, including their density, shape, and
Morteza Moradi et al.
The Analyst, 137(15), 3549-3557 (2012-06-27)
Hollow fiber-based liquid phase microextraction (HF-LPME) using conventional solvents is limited by their relative instability and high volatility. The use of supramolecular solvents as a liquid membrane phase could overcome these inconveniences due to their negligible vapour pressure and high
Kai Li et al.
The Journal of biological chemistry, 285(15), 11106-11113 (2010-02-02)
Heparan sulfate (HS) is involved in essential physiological and pathophysiological functions. HS is a highly sulfated polysaccharide consisting of glucuronic acid (or iduronic acid) linked to glucosamine carrying various sulfo groups. Biosynthesis of HS involves sulfotransferases and an epimerase. The
Svante Vikingsson et al.
Journal of pharmaceutical and biomedical analysis, 75, 145-152 (2012-12-25)
A high-performance liquid chromatography method capable of measuring thiopurine mono-, di-, and triphosphates separately in red blood cells (RBCs) was developed. RBCs were isolated from whole blood using centrifugation. Proteins were precipitated using dichloromethane and methanol. The thioguanine nucleotides (TGNs)
Vaibhav Tiwari et al.
Journal of virology, 80(18), 8970-8980 (2006-08-31)
Herpes simplex virus type 1 (HSV-1) infection of the corneal stroma remains a major cause of blindness. Primary cultures of corneal fibroblasts (CF) were tested and found susceptible to HSV-1 entry, which was confirmed by deconvolution imaging of infected cells.
Matt Petrowsky et al.
The journal of physical chemistry. B, 116(33), 10098-10105 (2012-07-31)
Onsager's model of the dielectric constant is used to provide a molecular-level picture of how the dielectric constant affects mass and charge transport in organic liquids and organic liquid electrolytes. Specifically, the molecular and system parameters governing transport are the
Muhammet Uyanik et al.
Science (New York, N.Y.), 345(6194), 291-294 (2014-07-19)
The diverse biological activities of tocopherols and their analogs have inspired considerable interest in the development of routes for their efficient asymmetric synthesis. Here, we report that chiral ammonium hypoiodite salts catalyze highly chemo- and enantioselective oxidative cyclization of γ-(2-hydroxyphenyl)ketones
Hiroyuki Nakao et al.
Biochimica et biophysica acta, 1848(1 Pt A), 145-150 (2014-10-15)
KcsA is a pH-dependent potassium channel that is activated at acidic pH. The channel undergoes global conformational changes upon activation. We hypothesized that the open-close conformational changes of the transmem brane region could promote the flip-flop of phosphoiipids. Based on
Samy Mohamady et al.
Current protocols in nucleic acid chemistry, Chapter 13, Unit13-Unit13 (2012-12-21)
This unit describes a method for preparing nucleoside polyphosphates and their conjugates such as nucleoside triphosphates, symmetrical and unsymmetrical dinucleoside polyphosphates and sugar nucleotides. The protocols employ sulfonyl imidazolium salts (SnISs) as coupling reagents. These reagents are prepared in two
Robert D Gray et al.
Nucleic acids research, 36(12), 4191-4203 (2008-06-24)
Cation-induced folding into quadruplex structures for three model human telomeric oligonucleotides, d[AGGG(TTAGGG)(3)], d[TTGGG(TTAGGG)(3)A] and d[TTGGG(TTAGGG)(3)], was characterized by equilibrium titrations with KCl and NaCl and by multiwavelength stopped flow kinetics. Cation binding was cooperative with Hill coefficients of 1.5-2.2 in
Zhenfeng He et al.
Dalton transactions (Cambridge, England : 2003), 41(33), 10043-10051 (2012-05-29)
A new kind of organic-inorganic hybrid complexes based on polyoxometalate were synthesized through symmetrically grafting two adeninyl groups onto Anderson-type MnMo(6) clusters and encapsulating the clusters by organic surfactants. The resultant complexes exhibited thermal-induced dynamic self-assembly behaviors which greatly depended
Y B Zhou et al.
Water science and technology : a journal of the International Association on Water Pollution Research, 66(4), 810-815 (2012-07-07)
Removal of phenanthrene (PHE) from aqueous solution by adsorption onto quaternary ammonium surfactant modified peat was studied. The results show that surfactant modification enhanced the PHE adsorption capacity of peat. Low temperature and neutral pH favored PHE adsorption. Peat modified
Chao Zhong et al.
Carbohydrate polymers, 94(1), 38-45 (2013-04-03)
In this article, a novel and high efficient solvent, tetra-n-Butylammonium Hydroxide (TBAH), was used for dissolution and isolation of straw cellulose from wheat straw. The composition analysis with gas chromatography (GC) and the spectroscopic characterization analysis conducted by X-Ray diffraction
David J Posson et al.
Nature structural & molecular biology, 20(2), 159-166 (2012-12-25)
Understanding how ion channels open and close their pores is crucial for comprehending their physiological roles. We used intracellular quaternary ammonium blockers, electrophysiology and X-ray crystallography to locate the voltage-dependent gate in MthK potassium channels from Methanobacterium thermoautotrophicum. Blockers bind
Michelle L Ingalsbe et al.
Bioorganic & medicinal chemistry letters, 19(17), 4984-4987 (2009-08-08)
Due to the increasing number of strains of drug-resistant bacteria, the development of new antibiotics has become increasingly important. The antibacterial properties of quaternary amines and their derivatives on both Gram-positive and Gram-negative bacteria are well known. However, an encompassing
J Liu et al.
The Journal of biological chemistry, 274(53), 38155-38162 (1999-12-23)
3-O-Sulfation of glucosamine by heparan sulfate D-glucosaminyl 3-O-sulfotransferase (3-OST-1) is the key modification in anticoagulant heparan sulfate synthesis. However, the heparan sulfates modified by 3-OST-2 and 3-OST-3A, isoforms of 3-OST-1, do not have anticoagulant activity, although these isoforms transfer sulfate
Mary Y Ryan et al.
Channels (Austin, Tex.), 6(6), 443-452 (2012-10-16)
RNA editing at four sites in eag, a Drosophila voltage-gated potassium channel, results in the substitution of amino acids into the final protein product that are not encoded by the genome. These sites and the editing alterations introduced are K467R
Shintaro Itagaki et al.
Chemical communications (Cambridge, England), 48(74), 9269-9271 (2012-08-10)
In the presence of Rh(2)(OAc)(4) (OAc = acetate) and TBA(2)WO(4) (TBA = tetra-n-butylammonium), the N-silylation of indole derivatives with hydrosilanes efficiently proceeded to give the corresponding N-silylated indoles in high yields. Pyrrole and carbazole were also N-silylated with the combined
Kosei Sugahara et al.
Chemical communications (Cambridge, England), 48(67), 8422-8424 (2012-07-14)
A tetra-n-butylammonium (TBA) salt of a γ-Keggin -6-charged germanodecatungstate, [γ-H(2)GeW(10)O(36)](6-) (I), could act as an efficient homogeneous catalyst for Knoevenagel condensation of active methylene compounds with carbonyl compounds.
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