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1.
Article | IMSEAR | ID: sea-220751

ABSTRACT

Oil-in-water emulsion has promised values in food, pharmaceutical, drug, cosmetic and allied industries. The stable emulsion with long shelf life increases its utility. Many avouring agents are used to increase shelf life as preservative or commercial value. Food grade acids are used to in the emulsion preparation which enhances the taste or avour. The present study focuses the usage of acetic acid, phosphoric acid and oxalic acid. The emulsions for different acids are prepared ranging concentration from 0.001 to 0.003M using lecithin as emulsier and sunower oil. Experiments were done to study organoleptic properties with respect to basicity and dissociation constant values. The colour of the primary emulsion was creamy white and sustainable for acetic acid emulsion to 28 day at experimental temperature 10, 25 and 40 0C. Oxalic acid is recorded a low pH value 1.88 for 0.003 M emulsion solution in compare with acetic acid (3.63) and phosphoric acid (2.32).The relative conductance measurement for oxalic acid shows a very high value 5.6mS to acetic acid 0.257mS and phosphoric acid 0.247 mS. The rst dissociation constant value 5.6x10-2 of oxalic acid is larger relatively compare to phosphoric acid 7.5 x 10-3 and acetic acid 1.8 x10-5. Basicity of acids increases from acetic acid (mono basic), oxalic acid (dibasic) to phosphoric acid (tri-basic).These results strongly supports that basicity and dissociation constant values of acids conspicuously inuence the stability of the emulsion. Higher value of dissociation constant value and basicity, lower the stability of the emulsion.

2.
Acta Pharmaceutica Sinica ; (12): 1530-2016.
Article in Chinese | WPRIM | ID: wpr-779321

ABSTRACT

The potassium channel encoded by the human ether-a-go-go related gene (hERG) plays a very important role in the physiological and pathological processes in human. hERG potassium channel determines the outward currents which facilitate the repolarization of the myocardial cells. Some drugs were withdrawn from the market for the serious side effect of long QT interval and arrhythmia due to blockade of hERG channel. The strategies for lead compound optimization are to reduce inhibitory activity of hERG potassium channel and decrease cardiac toxicity. These methods include reduction of lipophilicity and basicity of amines, introduction of hydroxyl and acidic groups, and restricting conformation.

3.
Rev. colomb. quím. (Bogotá) ; 35(2): 215-224, jul.-dic. 2006. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-636594

ABSTRACT

Se estudian las interacciones de cinco muestras de carbón activado obtenidas a partir de diferentes materiales lignocelulósicos, con diferente grado de activación alrededor de 20%, con soluciones acuosas de fenol y 4-nitro fenol mediante la determinación de las entalpías de inmersión. Se establece que los carbones activados obtenidos son de carácter básico y presentan valores para el punto de carga cero (PZC), que varían entre 7,4 y 9,7, y contenidos de basicidad total mayores en todos los casos que los valores obtenidos para la acidez total. Se determina la entalpía de inmersión de los carbones activados en soluciones de NaOH y HCl con valores mayores para la entalpía de inmersión en HCl que se encuentran entre 32,6 y 68,3 Jg-1. Las entalpías de inmersión en solución de fenol se hallan entre 7,6 y 13,9 Jg-1, y para el caso del 4-nitro fenol se encuentran entre 12,7 y 20,5 Jg-1; con valores mayores para todas las muestras para la inmersión en el segundo compuesto.


The interactions between five samples of activated carbon with different activation grades (~20%, obtained from different lignocellulose’ s materials) and aqueous solutions of phenol and 4-nitrofenol were studied by determining the values of the immersion enthalpy. From this study, it is established that the activated carbons exhibit a basic character and show values for the point of zero charge (PZC) between 7.4 and 9.7; also, the total basicity content is greater in all cases than the value obtained for the total acidity. The immersion enthalpy values of the activated carbons in NaOH and HCl solutions were determined, yielding larger values in the case of HCl which are between 32.6 -68.3 Jg-1. The inmersion enthalpy values in phenol solution range between 7.6 y 13.9 Jg-1 and for 4-nitro fenol between 12.7 y 20.5 Jg-1; all the samples displayed greater values after immersion in the second compound.

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