Search results for "Propanol"
showing 10 items of 217 documents
Phase equilibria and interfacial tension between coexisting phases for the system water/2-propanol/poly(acrylic acid)
1995
The cloud point curve, tie-lines and interfacial tensions were measured for solutions of 50 mol-% neutralized (counter-ion Na ○+ ) poly(acrylic acid) (molar mass M w = 9 700 g/mol; polydispersity index M w /M n = 2,0) in the mixed solvent water/2-propanol at 30°C. Due to the non-uniformity of the polymer, the end-points of the tie-lines are not situated on the cloud-point curve. The interfacial tension σ, determined by means of the spinning drop method, increases in sigmoidal manner with R tl , the length of the tie-line, expressed in terms of weight fractions. An evaluation of these data in a double-logarithmic plot of σ.M -0,5 versus R tl yields a critical exponent of 4,23 as compared wit…
Apparent Molar Volumes of Calcium Nitrate in 1-Propanol + Water at 298.15 K
1999
The densities of 1-propanol + water + calcium nitrate mixtures have been measured with an oscillating-tube densimeter over a large range of concentrations of the salt and 1-propanol, at 298.15 K. From these densities, apparent molar volumes of calcium nitrate in 1-propanol + water mixtures have been calculated, and partial molar volumes at infinite dilution have been evaluated.
Origin and correction of the deviations in retention times at increasing flow rate with Chromolith columns.
2010
Chromoliths can be used at flow rates beyond those feasible for conventional microparticulate packed columns. Ideally, the plots of the retention time versus the inverse of delivered flow rate should exhibit y-intercept of zero. However, significant positive deviations correlating with the solute polarity were observed for several compounds chromatographed with a Chromolith column, owing to the increased system pressure. Consequently, the dead time marker exhibits a smaller deviation, making the retention factors depend on the flow rate. Chromoliths are made of a silica-based monolith encapsulated within a PEEK tube, and should suffer larger stress with pressure than stainless steel columns…
Liquid–liquid equilibria of the systems dipropyl ether+n-propanol+water and dipropyl ether+n-propanol+ethylene glycol at different temperatures
2007
Abstract In this work, experimental liquid–liquid equilibria (LLE) data of the dipropyl ether + n-propanol + water and dipropyl ether + n-propanol + ethylene glycol systems are presented. The LLE of both systems have been measured at 283.15 and 323.15 K. The equilibrium data presented are correlated using NRTL and UNIQUAC equations. The reliability of these models is tested by comparison with experimental results. Moreover, the solvent capabilities of water and ethylene glycol were compared, concluding that ethylene glycol is the best solvent to extract n-propanol.
Modulation of drug transport by selected flavonoids: Involvement of P-gp and OCT?
2004
Flavonoids, as a common component of daily nutrition, are a possible source of interference with absorption processes, due to modulation of transporting proteins. In this study, the influence of selected flavonoids (quercetin, isoquercitrin, spiraeoside, rutin, kaempferol, naringenin, naringin, and kaempferol) on the transport of the P-gp substrate [3H]talinolol across Caco-2 cell monolayers was investigated. To elucidate the mechanism behind the interaction observed in this system the potency of the flavonoids to replace [3H]talinolol from its P-gp binding site as well as their activity to inhibit OCT2-mediated [14C]TEA uptake into LLC-PK(1) cells were measured, as P-gp and OCT have been s…
Determination of active ingredients in cough-cold preparations by micellar liquid chromatography.
2000
The chromatographic behaviour of some active ingredients in cough-cold pharmaceutical preparations, the antihistamine chlorpheniramine (or the dextro enantiomer dexchlorpheniramine), and the phenethylamines phenylephrine, phenylpropanolamine and pseudoephedrine, has been studied using a C(18) column, micellar mobile phases of sodium dodecyl sulphate (SDS) and pentanol, and with UV detection. All possible combinations of chlorpheniramine/phenethylamine were resolved and determined using a mobile phase of 0.15 M SDS-6% (v/v) pentanol at pH 7, with analysis time below 7 min. Repeatabilities and within laboratory precisions were evaluated at four different drug concentrations in the range 0.5-2…
Paper-TiO2 composite: An effective photocatalyst for 2-propanol degradation in gas phase
2018
Two simple routes for the synthesis of a paper-TiO2 composite were tuned up and the efficiency of the resulting paper-TiO2 photocatalyst was investigated in the 2-propanol oxidation in gas phase. The first route involved the in-situ generation over the sheet of paper of a TiO2 layer starting from a solution of Ti (OBu)4 in tert-butanoliacetic acid, followed by hydrothermal treatment at 120 degrees C for 3 h. The sample was labelled as paper-TiO2 (H). The second approach was based on the adsorption on the paper of a ready-made suspension of titania nanoparticles (TiO2 sol), generated in autoclave at 140 degrees C and stable in acid medium at pH <3. The sample was labelled as paper-TiO2 (S). …
Stereoselective synthesis of 1-aminoalkanephosphonic acids with two chiral centers and their activity towards leucine aminopeptidase
2003
The stereoselective synthesis of 1-amino-2-alkylalkanephosphonic acids, namely, compounds bearing two chiral centers, was achieved by the condensation of hypophosphorous acid salts of (R)(+) or (S)(-)-N-alpha-methylbenzylamine with the appropriate aldehydes in isopropanol. Simultaneous deprotection and oxidation by the action of bromine water provided equimolar mixtures of the RS:RR and SR:SS diastereomers of desired acids. They appeared to act as moderate inhibitors of kidney leucine aminopeptidase with potency dependent on the absolute configuration of both centers of chirality.
New Analgesics Designed by Molecular Topology
1996
Molecular topology has been applied to the design of new analgesic drugs, utilizing linear discriminant analysis and connectivity functions using different topological descriptors. Of a total of 26 compounds selected, 17 showed analgesic activity. The following stood out particularly, showing analgesic values greater than 75% regarding ASA (acetylsalicylic acid), the reference drug: 2-(1-propenyl)phenol, 2′4′ dimethylacetophenone, p-chlorobenzohydrazide, 1-(p-chlorophenyl) propanol and 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one. The usefulness of the design method has been demonstrated in the search of new chemical structures having analgesic effects, some of which could become “lead dru…
Pharmacological studies of 1-(p-chlorophenyl)propanol and 2-(1-hydroxy-3-butenyl)phenol: Two new non-narcotic analgesics designed by molecular connec…
1997
Abstract Molecular topology has been applied to the design of new analgesic drugs. Linear discriminant analysis and connectivity functions were used to design two potentially suitable drugs which were synthesized and tested for analgesic properties by the acetic acid-induced abdominal constriction test in mice and the tail-flick test in rats. In mice, the compound 1-(p-chlorophenyl)propanol showed higher analgesic activity, both intraperitoneally and orally, than acetylsalicylic acid. 2-(1-Hydroxy-3-butenyl)phenol exhibited a lesser protective effect (70% of that shown by acetylsalicylic acid). In rats, acetylsalicylic acid gave the greatest protection against pain when administered intrape…