- Head group specificity of novel functionalized surfactants: Synthesis, self-assembly and calcium tolerance
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The present work describes the synthesis, characterization and application of functionalized surfactants derived through simple organic reaction steps. These surfactants have been particularly tailor made to resist hardness due to calcium ions in water. It is unique of its kind because here the surfactants have an analogous hydrophobic chain but differ structurally in the composition of the head groups in terms of the position of attachment of the chain. The effect of this small variability in the head group on the surfactant property, adsorption, self assembly and calcium tolerance behaviour has been studied in detail. This kind of phenol-keto surfactants has not been reported before. It was also found that one of the surfactants was more tolerant towards Ca2+ion than the other. The individual packing behaviour of the surfactants at the air-water interface has been projected to cause this difference which is very interesting.
- Sarkar, Deboleena,Shukla, Ravi Kant,Gadgil, Vijay,Pramanik, Amitava
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supporting information
p. 5925 - 5931
(2015/01/16)
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- Synthesis, biochemical evaluation and rationalisation of a series of 3,5- dibromo derivatives of 4-hydroxyphenyl ketone-based compounds as probes of the active site of type 3 of 17β-hydroxysteroid dehydrogenase (17β-hsd3) and the role of hydrogen bonding interaction in the inhibition of 17β-HSD3
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We report the synthesis, evaluation and rationalisation of the inhibitory activity of a series of 3,5-dibromo derivatives of 4-hydroxyphenyl ketone as probes of the active site of the type 3 of 17β-hydroxysteroid dehydrogenase (17β-HSD3). The results support the important role of hydrogen bonding interaction in the inhibition of 17β-HSD3.
- Olusanjo, Moniola S.,Mashru, Shreena N.,Cartledge, Timothy,Ahmed, Sabbir
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scheme or table
p. 604 - 610
(2012/08/28)
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- Synthesis and critical micelle concentration of a series of gemini alkylphenol polyoxyethylene nonionic surfactants
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A series of gemini n-alkylphenol polyoxyethylene surfactants (GAP) were successfully synthesized and their molecular structure were confirmed by NMR and FTIR spectrum. Using the same synthesis route, a Gemini nonylphenol polyoxyethylene surfactant (GNP) was synthesized using an industrial nonylphenol product and paraformaldehyde, and its molecular structure was also characterized by 1H-NMR and FTIR spectra. The optimal reaction conditions were established. The critical micelle concentration (CMC) values of GAP were determined by means of Wilhelmy plate method and steady-state fluorescence probe method. The experimental results show how the lengths of the hydrophilic polyoxyethylene chain and the hydrophobic tail alter the CMC values. The CMC values of the GAP are found to be much lower than those of corresponding conventional single tail nonionic surfactants of the polyethoxylated alkylphenol type, which indicates that the gemini species exhibit a better surface activity. AOCS 2011.
- Yang, Fang,Li, Gang,Xu, Nian,Liu, Rong,Zhang, Song-Mei,Wu, Zeng-Jiang
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p. 339 - 345
(2012/06/30)
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- Synthesis and biochemical evaluation of a series of trifluoromethanesulfonate derivatives of 4 hydroxyphenyl ketones - Probes of the active site of type 1 and 3 of the 17β-hydroxysteroid dehydrogenase family of enzymes
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In an effort to aid the design of 'dual-inhibitors' of types 1 and 3 of the 17β-hydroxysteroid dehydrogenase (17β-HSD), we report the synthesis, biochemical evaluation and rationalisation of the inhibitory activity of trifluoromethanesulfonate derivatives of 4-hydroxyphenyl ketone-based compounds which were found to be weak inhibitors of types 1 and 3.
- Olusanjo, Moniola S.,Cartledge, Timothy,Shah, Kruti,Ahmed, Sabbir
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p. 253 - 259
(2013/01/10)
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- Synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a series of 4-hydroxyphenyl ketones as potential inhibitors of 17β-hydroxysteroid dehydrogenase type 3 (17β-HSD3)
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We report the preliminary results of the synthesis and biochemical evaluation of a number of 4-hydroxyphenyl ketones as inhibitors of the isozyme of the enzyme 17β-hydroxysteroid dehydrogenase (17β-HSD) responsible for the conversion of androstenedione (AD) to testosterone (T), more specifically type 3 (17β-HSD3). The results of our study suggest that we have synthesised compounds which are, in general, potent inhibitors of 17β-HSD3, in particular, we discovered that 1-(4-hydroxy-phenyl)-nonan-1-one (8) was the most potent (IC50 = 2.86 ± 0.03 μM). We have therefore provided good lead compounds in the synthesis of novel non-steroidal inhibitors of 17β-HSD3.
- Lota, Rupinder K.,Dhanani, Sachin,Owen, Caroline P.,Ahmed, Sabbir
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p. 4519 - 4522
(2007/10/03)
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- Selectivity in the photodimerization of 6-alkylcoumarins
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Coumarin and 6-alkylcoumarins (alkyl = C1 to C16) were photodimerized in homogeneous solvents differing in polarity and in aqueous micellar solutions. The four possible photodimers, syn head-to-head (hh), anti head-to-head, syn head-to-tail (ht), and anti head-to-tail, were identified through a combination of X-ray analysis and NMR spectroscopy. In 6-methylcoumarin the concentration-corrected dimerization (quantum) yield increases with decreasing concentration of the educt; anti- hh was formed exclusively in nonpolar solvents and upon triplet sensitization and was the main product under all conditions except for ionic micellar systems, which direct to preferred syn-hh dimerization. Long alkyl substituents, however, lead to anti-hh in polar solvents and in micelles, too. Predominating ht dimer formation was observed for nonsubstituted coumarin in polar solvents only. Thus, syn/anti and hh/ht selectivity can be steered by varying the 6-alkyl substituent. Syn- hh photodimers of 6-methylcoumarin can be photochemically split into the monomers; they partly proved thermally unstable against acids, bases, methanol, and on SiO2 surfaces.
- Yu, Xiuling,Scheller, Dieter,Rademacher, Otto,Wolff, Thomas
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p. 7386 - 7399
(2007/10/03)
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- Tilt Angle Variation as a Function of Chain Length and Temperature in the Smectic C Phases of p,Alkoxyphenyl-p,Alkoxybenzoates
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The variation of the tilt angle with temperature in the smectic C phase has generally been shown to be non-existent or very slow for compounds or mixtures with the nematic-smectic C transition, while in the case of systems with the smectic A-smectic C transition, a relation between the steepness of this variation, near the transition, and the width of the smectic A domain has been observed.In this work, the variation of tilt angle in the smectic C phase is described for p-alkoxyphenyl-p-alkoxybenzoate homologous series, for which the evolution of polymorphism can be controlled systematically, by varying stepwise the length of the aliphatic chains, and for which large domains can be obtained for each type of phase sequence, nematic-, smectic A- and isotropic-smectic C.After completing the discussion made previously on the incidence of chain length on polymorphism, we confirm that the variation of tilt angle with temperature is slowest for compounds with intermediate chain lengths corresponding to the largest smectic A temperature range; this variation becomes continuously steeper when the smectic A domain becomes narrow.In addition, we show that the same description can be extended to the other types of phase sequences, by using the hypothesis of a virtual smectic A-smectic C transition above the observed nematic- or isotropic-smectic C transition.In fact, short chain lengths for homologues with a nematic/smectic C transition, or long chain lengths for homologues with an isotropic/smectic C transition, lead to an increase of the tilt angle at the phase transition and to a decrease of the amplitude of its variation with temperature; in our description, this behaviour corresponds to an increase of the temperature range between the real and virtual transitions.As a consequence, the homologues with very short and very long chain lengths show a quasi temperature-independent tilt angle, while the other homologues present a tilt angle variation similar to that observed for compounds exhibiting a smectic C/smectic A transition.This feature indicates that there is no need to distinguish between different types of smectic C phase.
- Heinrich, B.,Guillon, D.
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- Alkyl-substituted 2,2'-(1,4-naphthalenediyl)dibenzoxazole and photographic support comprising the same
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An alkyl-substituted 2,2'-(1,4-naphthalenediyl)dibenzoxazole represented by the structural formula [I]: STR1 wherein R1 and R2 are independently alkyl groups having 9-20 carbon atoms, m and n are independently 0 or positive integers and m+n=1-4, and a photographic support comprising the alkyl-substituted 2,2'-(1,4-naphthalenediyl)dibenzoxazole as a fluorescent agent. The photographic support comprising the same has bright whiteness and does not cause color change or bleeding out.
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- Synthesis, Spectral Data and Extraction of Copper by 1-(2'-Hydroxy-5'-alkylphenyl)-1-alkanone Oximes
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1-(2'-Hydroxy-5'-alkylphenyl)-1-ethanone oximes with a normal alkyl group containing 2 to 12 carbon atoms and 1-(2'-hydroxy-5'-methylphenyl)-1-alkanone oximes containing 1 to 11 carbon atoms in the hydrocarbon chain were synthesized.Spectral data (u.v., i.r., n.m.r. and 13C) of oximes are reported.Four of these oximes were used for copper extraction from acidic solution.The results obtained indicate, that these oximes are better extractants than alkyl derivatives of 2-hydroxybenzophenone oximes.
- Krzyzanowska, Ewa,Olszanowski, A.,Juskowiak, M.
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p. 617 - 630
(2007/10/02)
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