salicylates and 5-methylsalicylic-acid

In this research, a simple, rapid, and efficient air assisted - vesicle based microextraction (AAVME) approach was developed for the extraction of phenolic compounds and their analysis in different Melissa officinalis L. samples. The extraction method is based injection an aqueous mixture of CTAB and 5-methyl salicylic acid, into the hydroalcoholic plant extract in a conical test tube to form a cloudy solution. Suction and dispersion were then applied to accelerate the dispersion process. After centrifugation, the sediment phase was removed and injected into HPLC system. The optimized extraction conditions were as 450 μL of a mixture of CTAB and 5-methyl salicylic acid (3:5 mol ratios), 10.0 mL sample solution at pH 8.0 and 30 suction-dispersion cycles. Under these extraction conditions, the proposed method was able to provide a good linearity (R

Topics: Air; Cetrimonium; Chemical Fractionation; Green Chemistry Technology; Melissa; Phenols; Phytochemicals; Plant Extracts; Plant Leaves; Plant Stems; Salicylates

A unilamellar polymeric vesicle is a self-assembled structure of a block copolymer that forms a spherical single bilayer structure with a hydrophobic interlayer and a hydrophilic surface. Due to their enhanced colloidal stability and mechanical property, controllable surface functionality, or tunable membrane thickness, polymeric vesicles are useful in nano and bio-science, providing potential applications as nanosized carriers for catalysts, drugs, and enzymes. For fabrication of a unilamellar vesicle, however, preparative procedures with a few steps are inherently required. Herein, without complicated preparative procedures, we report spontaneous unilamellar polymeric vesicles with nanometer sizes (<100 nm), which are prepared by simply mixing a triblock copolymer, Pluronic P85 (PEO26PPO40PEO26), and an organic derivative, 5-methyl salicylic acid (5mS), in aqueous solution. Depending on the 5mS concentration and the temperature, the P85-5mS mixtures presented various self-assembled nanostructures such as spherical and cylindrical micelles or vesicles, which were characterized by small angle neutron scattering and cryo-TEM, resulting in a phase diagram drawn as a function of temperature and the 5mS concentration. Interestingly the critical temperature for the micelle-to-vesicle phase transition was easily controlled by varying the 5mS concentration, i.e. it was decreased with increasing the 5mS concentration.

Topics: Catalysis; Drug Carriers; Micelles; Nanostructures; Poloxamer; Polymers; Salicylates; Temperature; Unilamellar Liposomes; Water

This article presents the interaction of curcumin in the microenvironments provided by aggregation of pluronic triblock copolymer P123 into micellar and vesicular assemblies. The formation of vesicles using triblock copolymer P123 and 5-methylsalicylic acid (5 mS) has been successfully characterized by optical spectroscopy, light scattering measurement, and eventually microscopic techniques. Besides, to make a comparative study between the polymeric micelles, we have also investigated the photophysical changes of curcumin in F127 triblock copolymer micelles having variation in poly(ethylene oxide) (PPO) and poly(propylene oxide) (PEO) unit of polymer chain to that of P123. Time-dependent UV-vis measurement suggests that these polymer micelles are able to stabilize poorly water-soluble curcumin by suppressing the degradation rate in micellar nanocavity. However, experimental observations suggest that P123 micelles are more efficient than F127 to perturb excited state intramolecular proton transfer (ESIPT)-related nonradiative decay of curcumin. We also observed that rigid and confined microenvironment of P123/5 mS vesicles enhances emission intensity and lifetime of curcumin more compared to P123 micelles. All the observations suggest that modulation of photophysics of curcumin is responsible due to its interaction with poly(ethylene oxide) or poly(propylene oxide) unit of triblock copolymer.

Topics: Curcumin; Light; Micelles; Poloxalene; Polyethylene Glycols; Polymers; Propylene Glycols; Salicylates; Scattering, Radiation; Spectrophotometry, Ultraviolet

Unilamellar vesicles are observed to form in aqueous solutions of the cationic surfactant, cetyl trimethylammonium bromide (CTAB), when 5-methyl salicylic acid (5mS) is added at slightly larger than equimolar concentrations. When these vesicles are heated above a critical temperature, they transform into long, flexible wormlike micelles. In this process, the solutions switch from low-viscosity, Newtonian fluids to viscoelastic, shear-thinning fluids having much larger zero-shear viscosities (e.g., 1000-fold higher). The onset temperature for this transition increases with the concentration of 5mS at a fixed CTAB content. Small-angle neutron scattering (SANS) measurements show that the phase transition from vesicles to micelles is a continuous one, with the vesicles and micelles coexisting over a narrow range of temperatures. The tunable vesicle-to-micelle transition and the concomitant viscosity increase upon heating may have utility in a range of areas, including microfluidics, controlled release, and tertiary oil recovery.

Topics: Cetrimonium; Cetrimonium Compounds; Hot Temperature; Micelles; Neutron Diffraction; Phase Transition; Rheology; Salicylates; Scattering, Small Angle; Unilamellar Liposomes; Viscosity

The effects of eighteen substituted benzoic acids on the rate of oxygen consumption have been studied in rats. 2:3-Dihydroxybenzoic acid, phthalic acid and 6-methylsalicylic acid were, at the doses used, inactive; m- and p-hydroxybenzoic acid, 2:4-, 2:5-, 2:6-, 3:4-, and 3:5-dihydroxybenzoic acid, o-aminobenzoic acid, salicyluric acid, salicylamide and 5-aminosalicylic acid decreased the rate of oxygen consumption. Only salicylic acid and o-, m- and p-cresotic acid (3-, 4- and 5-methylsalicylic acid respectively) increased the rate of oxygen consumption. Molar potency ratios of the cresotic acids as metabolic stimulants relative to salicylic acid were determined; o-cresotic acid was the most powerful with a ratio of 2.61, m- and pcresotic acid had values of 1.78 and 1.89 respectively. Two possible explanations of the higher potencies of the cresotic acids were considered. No difference in the primary action of the drug was established by determining the effect on rate of oxygen consumption of a mixture of o-cresotic and salicylic acids. An alternative possibility was that the rates of detoxication and excretion of the cresotic acids differed among themselves and from salicylic acid. No such differences were found.

Topics: Animals; Benzoates; Central Nervous System Agents; Central Nervous System Stimulants; Hippurates; Hydroxybenzoates; Male; Mesalamine; Metabolism; ortho-Aminobenzoates; Rats; Salicylates