- Contact allergens from surfactants. Atmospheric oxidation of polyoxyethylene alcohols, formation of ethoxylated aldehydes, and their allergenic activity
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Ethoxylated surfactants are susceptible to oxidation upon air exposure. We have previously studied the rate of peroxidation and formaldehyde formation in the chemically well-defined ethoxylated alcohol C12H25(OCH2)5OH. Formaldehyde is a common cause of contact allergy. The aim of the present study was to identify other oxidation products that could be formed upon air exposure of the ethoxylated alcohol and to determine their allergenic activity. It was shown that air oxidation of C12H25(OCH2CH2)5OH gave all the theoretically possible aldehydes of the general formula C12H25(OCH:2Ch2)(n)OCH2CHO (n = 0-4) and that the major oxidation product was C12H25(OCH2CH2)4OCH2CHO, dodecyltetraoxyethyleneoxyacetaldehyde. The structure elucidation and synthesis of these aldehydes are here presented for the time. The major aldehyde was shown to be a contact allergen with the same sensitizing capacity as that of formaldehyde. A dose-response relationship was observed in the sensitization studies. The allergens were formed from the surfactant itself and the skin reactions cannot be explained due to any impurities that may be present in a technical quality of the surfactant. Cases of allergic contact dermatitis to ethoxylated surfactants have been reported. To avoid the formation of allergenic oxidation products it is important to control the conditions for storage, handling, and transportation of ethoxylated surfactants.
- Bergh, Margareta,Shao, Li Ping,Hagelthorn, Gunnel,Gaefvert, Elisabeth,Nilsson, J. Lars G.,Karlberg, Ann-Therese
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- Efficient synthetic supramolecular channels and their light-deactivated ion transport in bilayer lipid membranes
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Inspired by the critical role of ion channel proteins in the regulation of cellular activities, here we developed a new type of synthetic ion channel by simple benzocrown ether-based derivatives M1 and M2, where M1 had a dodecyl tail and M2 had a diethylene glycol-conjugated dodecyl tail. Being amphiphilic in nature, the two small molecules were assumed to form crown ether channels through supramolecular interactions in bilayer lipid membranes (BLMs). The efficient ion transport was investigated by both a fluorescence-based vesicle assay and a planar bilayer conductance measurement, and M2 with diethylene glycol substitution exhibited more efficient activity comparable to amphotericin B. Moreover, the presence of a photosensitive o-nitrobenzyl group provided the light-regulation to deactivate ion transport by destroying the channel assembly of the molecules in BLMs, which provides new opportunities for developing intelligent light-regulated systems for biomedical applications based on synthetic small molecules.
- Bao, Chunyan,Ma, Meixin,Meng, Funa,Lin, Qiuning,Zhu, Linyong
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- Drug carrier based on sulfonium lipidosome structure and preparation method and application of drug carrier
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The invention relates to the technical field of medicine, in particular to a sulfonium compound shown as a general formula (A), and discloses a preparation method of the compound. The compound is poly-condensed with genes to form a nanometer compound with the particle size of 100-300 nm and Zeta potential of +20-+40. The gene loading capability of the sulfonium compound enables the sulfonium compound to have potential application in gene transfer.
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Paragraph 0049; 0052-0054
(2019/08/14)
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- Polyoxyethylene ether carboxylic acid dimeric surfactant type drag reducer as well as preparation method and application thereof
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The invention discloses a polyoxyethylene ether carboxylic acid dimeric surfactant type drag reducer as well as a preparation method and application thereof. The polyoxyethylene ether carboxylic aciddimeric surfactant type drag reducer has a structure formula m=2, 3, 4, and n=1, 2, 3. The drag reducer disclosed by the invention is a dimeric surfactant type drag reducer which has a head group of carboxylic acid, and the head group has the advantages of being very good in temperature resistance, salt resistance, environment protection and the like, and is capable of overcoming influence of a high-salt environment upon drag reduction performance, so that the drag reducer disclosed by the invention is high in drag reduction efficiency, good in shearing resistance, long-lasting and stable in drag reduction rate and good in salt resistance; and polyoxyethylene ether carboxylic acid dimeric surfactants of different mass concentrations are dissolved into water, a drag reduction solution whichis high in drag reduction efficiency, good in shearing resistance, long-lasting and stable in drag reduction rate and good in salt resistance can be prepared without any other compounded chemical reagent, solution blending steps are simple, the drag reducer is very convenient to use, and meanwhile, the salt resistance is greatly improved.
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Paragraph 0087-0089; 0114-0116; 0141-0143
(2019/09/13)
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- Synthesis of some acyclic quaternary ammonium compounds. Alkylation of secondary and tertiary amines in a two-phase system
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A series of acyclic symmetrical and asymmetrical quaternary ammonium chlorides of the general formula R1R2R3N+AR4Cl- (R1 = Me, Bu; R2 = n-C12H25, PhCH2, C n H2n+1(OCH2CH2) m, n = 9 and 12, m = 1 and 2; R3 = n-C12H25, PhCH2, HOCH2CH2,-OOCCH2; R4 = n-C12H25, PhCH2; A = (CH2CH2O)1,2, CH2C(O)O) was synthesized by the alkylation of tertiary amines in a two-phase system containing water. A convenient method for the synthesis of the initial symmetrical and asymmetrical tertiary amines of the general formula MeNR1R2 (R1 = Me, Bu; R2 = n-C12H25, PhCH2, CnH2n+1(OCH2CH2) m, n = 9 and 12, m = 1 and 2) in an organic phase-aqueous phase heterogeneous system, which allows the use of aqueous solutions of alkali and amines, was developed. The improved method for the preparation of intermediate ethylene glycol and diethylene glycol monoethers is monoalkylation of glycols in dioxane using solid KOH in a two-phase system.
- Kharlamov,Artyushin,Bondarenko
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p. 2445 - 2454
(2015/08/03)
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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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- Method for carrying out reactions characterized by an equilibrium
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The invention relates to a process for conducting a chemical reaction characterized by an equilibrium in a reaction system designed as a loop reactor, said loop reactor comprising a reactor vessel (1), at least one loop connected to said reactor vessel (1) each by means of an outlet and an inlet, said loop comprising means (3) for pumping over a fluid reaction material, at least one he exchanger (4), optionally means (5) for feeding said reaction material into Me reactor vessel (1) and a separate gas loop (8) which is connected to the gas space of the reactor vessel (1) above the reaction mixture and has separate means for feeding a gas into the gas loop (8), for withdrawing gas from the gas loop (8) and/or for treating said gas circulating in the gas loop (8), said process comprising the steps of circulating and/or treating said gas in said gas loop (8), feeding said gas into the reactor vessel (1) for influencing the equilibrium of a reaction conducted in said reactor vessel (1) and being characterized by the equilibrium and, after influencing said equilibrium reaction conducted in said reactor vessel (1), exhausting said gas from said reactor vessel (1) into the gas loop (8).
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Page column 14
(2008/06/13)
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- Atmospheric oxidation of poly(oxyethylene) alcohols. Identification of ethoxylated formates as oxidation products and study of their contact allergenic activity
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Ethoxylated alcohols are widely used as surfactants. In the present study we have continued our investigations on the degradation with time upon air exposure of the ethoxylated alcohols at normal storage and handling. As a result, a new group of ethoxylated formates with the general formula C12H25(OCH2CH2)(n)OCHO (n = 0-4) was identified in C12H25(OCH2CH2)5OH stored and handled at room temperature. To facilitate the identification work, reference compounds were synthesized. The formates showed no allergenic activity in the sensitization studies performed. In previous investigations on the same ethoxylated alcohol, we have identified formaldehyde and ethoxylated aldehydes among the oxidation products formed. Formaldehyde is a common contact allergen, and the ethoxylated aldehydes were shown to have a sensitizing capacity of the same magnitude as formaldehyde. The instability of the ethoxylated alcohols and formation of oxidation products may give an allergenic contribution to hand eczema caused by work with water and surfactants. To investigate the clinical significance in man an appropriate diagnostic patch testing in exposed humans is required.
- Bergh, Margareta,Shao, Li Ping,Magnusson, Kerstin,Gaefvert, Elisabeth,Nilsson, J. Lars G.,Karlberg, Ann-Therese
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p. 483 - 488
(2007/10/03)
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- Production process for (poly)alkylene glycol monoalkyl ether
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The present invention provides a process for producing a (poly)alkylene glycol monoalkyl ether with high selectivity and high yield. In this process, the (poly)alkylene glycol monoalkyl ether is produced by reacting an olefin and a (poly)alkylene glycol in the presence of a catalyst, wherein: 1) a crystalline metallosilicate is used as the catalyst, and at least a portion of the used catalyst is regenerated, and the regenerated catalyst is recycled as the catalyst for the reaction; or 2) the reaction between the olefin and the (poly)alkylene glycol is carried out in the presence of either or both of a (poly)alkylene glycol dialkyl ether and an alcohol.
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- Kinetics of the Acid-catalysed Hydrolysis of Dodecylsulphate and Dodecyldiethoxysulphate Surfactants in Concentrated Micellar Solutions. Part 1. - Effects of Acid and Surfactant Concentrations and of the Nature and Concentration of Counterions
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The rates of the acid-catalysed hydrolysis of sodium dodecylsulphate (SDS) and sodium dodecyldiethoxysulphate (SDE2S) have been investigated in concentrated surfactant solutions (0.035 - 0.6 mol dm-3).The acid concentration dependence of the initial rates shows a 'saturation' effect, whereas increasing surfactant concentrations above the c.m.c. lead to a maximum in the k2,obs values, beyond which they decrease sharply.These results are discussed in terms of the ion-exchange pseudophase model of the miceller reaction.The nature of the counterion has an effect on k2,obs, the values following the sequence NH4 > Li > Na >> Mg.This has been ascribed to differences in the ion-exchange constants, KH/X, of these cations in the Stern layer of the micelles with the hydrogen ion.Maintaining the total counterion concentration and the ratio of concentrations of surfactant counterion to the concentration of hydrogen ion constant (at 30, i.e. 0.6 : 0.02 mol dm-3) largely eliminates the decrease in the k2,obs values with increasing surfactant concentration, as expected from the pseudo-phase ion-exchange model.Quantitative agreement between theory and experiment is less good, however, owing at least partly to deviations from ideality in solutions of high ionic strength.
- Garnett, Christopher J.,Lambie, Alan J.,Beck, William H.,Liler, Milica
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p. 953 - 964
(2007/10/02)
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