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The micellar aggregation of a series of gemini surfactants [N, N’-dimethyl-N, N’-bis(2-alkylamideethyl)-ethylenediamine oxide (alkyl = C11H23, C13H27, C15H31)] in aqueous media has been investigate...

Two types of novel amine oxide surfactants, castor oil amide amine oxide and cottonseed oil amide amine oxide, have been successfully synthesized via a two-step synthetic route with mild reaction c...

In this paper, a novel type of pH- and temperature-responsive smart wormlike micelles based on (Z)-N,N-dimethyl-3-(octadec-9-enamido) propan-1-amine oxide (OAPAO) synthesized was studied. The struc...

A new kind of amine oxide surfactant – cocotriethoxylpropanediamine oxide (CTPDAO) – was synthesized by a two-step process. The molecular structure was characterized by FTIR spectra and 1H NMR. The new surfactant showed high surface activity in aqueous solution in the surface tension measurement. Emulsifying capacity and wetting ability were studied in comparison to dodecyldimethylamine oxide (DDMAO). The results indicate that this new surfactant could reach the lowest surface tension of 30.4 mN m−1 in aqueous solution with a critical micelle concentration (CMC) of 0.23 mmol L−1. The wetting ability of DDMAO is better than that of CTPDAO. Compared with CTPDAO, DDMAO shows a greater capacity to emulsify soybean oil, although CTPDAO is a better emulsifying agent for liquid paraffin. The foaming properties and thickening function of DDMAO and CTPDAO mixed with alcohol ether sulfate (AES) and dodecylbenzene sulfonate (LAS) were also investigated. The results show that CTPDAO is a superior foam stabili...

Two new morphinane alkaloids, 1-hydroxy-10-oxo-sinomenine (1) and 4,5-epoxy-14-hydroxy sinomenine N-oxide (2), have been isolated from the stems of Sinomenium acutum. Their structures were established by various spectral analyses, especially 2D NMR experiments. The structure of 2 was confirmed by single crystal X-ray diffraction. The absolute configurations of 1 and 2 were deduced by comparison of CD spectra with the known alkaloid sinomenine (3). Compound 1 was tested for DPPH inhibition and gave IC(50) of 27.9 μM. Compound 2 was tested for neuroprotective effect and showed significant activity against β-amyloid(25-35)-induced oxidative injury (*P 0.05) at 10 μM in PC-12 cells.

Effect of organic additives on the dynamic behavior of surfactant in solution was studied using the maximum bubble pressure method. Dynamic surface tension of solution of sodium lauryl sulphate (SLS) was measured at different concentrations with various additives. Additives such as lauric acid diethanol amide (LDEA), cocoamidopropyl betaine (CAPB), lauryl amido propyl betaine (LAPB), and lauryl amido propyl amine oxide (LAPAO) were employed for this study. The concentration of surfactant mixture needed to reduce surface tension to the defined quantity within the time available for adsorption is compared.

A methodology, based on tandem [2,3] and [3,3] sigmatropic rearrangement, has been described for the synthesis of hitherto unreported, potentially bioactive pyrrolo[3,2‐c][1]benzothiopyran‐4‐ones (6a–g) derivatives.

We have investigated the mixing behavior of the mixtures of dodecyldimethylamine oxide (DDAO) and Triton X‐100 (TX‐100) at different ratios of the two surfactants and at different values of pH. From the equilibrium surface tension measurements, the critical micelle concentration (CMC) and surface tensions at CMC data were obtained as functions of the composition. For the binary mixtures of dodecyldimethylamine oxide and TX‐100 at different ratios in the natural values of pH, the behaviors of the mixtures deviate positively from ideal during micellization. The minimum of CMC of the mixtures of dodecyldimethylamine oxide and Triton X‐100 was observed in the range 4.0

The phase diagram for the Genaminox 1216 (a zwitterionic surfactant), pentanol‐water system has been constructed at 25°C. The sequence of the phases varies from L1, L1*/Lα, Lα, two phases and L2 as the system was made more lipophilic. Identification of the phases was done by means of crossed polarizer, electrical conductivity and optical polarizing microscopy techniques. Through surface tension measurements, a critical micelle concentration (CMC) of 9 × 10−4 M for the surfactant in aqueous solution was determined. Aromatic salts (such as sodium salicylate and sodium benzoate) reduce the value of this CMC more than aliphatic salts (a sodium citrate and sodium oxalate).This behavior indicates that aromatic salts promote the surfactant assembly more than aliphatic salts. Methyl orange (MO) was used as a solvatochromic reporter to study the nature of interaction of additives with the surfactant by using a UV‐vis technique. The λmax absorption band for aqueous MO has a peak at 463 nm. A blue shift in ...

The ternary phase diagrams of zwitterionic single-chain hydrocarbon surfactant (tetradecyldimethylaminoxide, C14DMAO)—a perfluoro cosurfactant (1,1-H-dihydroperfluorooctanol, C7F15CH2OH)-H2O, and C14DMAO-C7F15CH2OH-H2O-HCl have been studied at 25°C. The identification of the phases was done by means of electrical conductivity, optical polarizing microscopy, and 2H-NMR techniques. In this system the originally uncharged zwitterionic surfactant was increasingly charged by protonation through addition of HCl. The sequence of the phases observed is similar to that observed for hydrocarbon surfactant–cosurfactant mixtures, namely, L1, L1/Lα, Lα and L2, as relative volume fraction of apolar compound increases over that of polar compound. The absence of sponge phase (L3) is a result of the high bending constant of the mixed bilayers in this perfluoro system.

The extraction of gold, silver, copper, zinc, and nickel present in thiosulfate solutions with or without the presence of ammonia was studied. Results show that neither a primary amine nor the mixed extractants of a primary amine with tributyl phosphate or trialkyl amine oxide can separate gold from other metals in the absence of ammonia in aqueous solutions. In the case of ammonium thiosulfate Solutions, the percent extraction of gold is increased tremendously in comparison with other metals, and thus gold can be separated from them. The pH(50) of gold extraction for a mixed solvent of primary amine with amine oxide is about 9.0, which is very close to the pH of the actual leaching solutions. By using the mixed solvent to extract gold in the solutions from leaching of gold-containing sulfide concentrate, the separation factors of Au to Ag and Au to Cu could reach as high as 15 and 1695, respectively, for a pH less than 8.

The extraction of gold from thiosulfate solutions with amine oxide and its mixture with amines has been studied, the results show that the amine oxide (TRAO) has a higher extraction ability for gold compared with tertiary amine. It can extract gold from neutral and weakly alkaline thiosulfate solutions, similar to the primary amine as extractant. The addition of TRAO enhances the extent of gold extraction with primary, secondary, and tertiary alkyl amines, respectively. The stoichiometry for the extraction of gold from thiosulfate solutions using the mixed solvent containing the primary amine N-1923 and the amine oxide TRAO was investigated using slope analysis. The compositions of the gold extraction species with mixed organic solvents are proposed.

The molecular orientation in the Langmuir-Blodgett (LB) films of octadecyl-dimethylamine oxide (C18DAO) and dioctadecyldimethylammonium chloride (2C18DAC) was estimated by a newly proposed calculation method for the infrared reflection-absorption (RA) spectral data. The Y- and X-type multilayer LB films of both compounds were prepared respectively as LB (Y) and LB(X) for the RA measurements. There found a large difference in thermal stability between the LB(Y) and LB(X) films for both compounds. Above all, the 9-monolayer LB(Y) films showed a structurally heterogeneous property. The molecular orientation in the heterogeneous structure was explored by introducing a new analyzing method. The method revealed that the first monolayer directly deposited on a gold surface had a specific molecular structure arising from the interaction with the substrate. The structure is different from that in the rest layers. The LB(X) films were found to be thermally very stable; the thermal recovery was notably good...

Monolayer Langmuir-Blodgett (LB) films of octadecyldimethylamine oxide (C18DAO), dioctadecyldimethylammonuim chloride (2C18DAC) and their mixtures with cinnamic acid were prepared on gold evaporated glass slides by use of the LB technique and their structures were investigated by infrared spectroscopy. The infrared study indicates that cinnamic acid exists as a monomer and its C═O group is nearly perpendicular to the substrate surface in the LB film of 2C18DAC mixed with cinnamic acid, while the C═O group is nearly parallel the substrate surface in the case of mixed film with C18DAO. The irradiation of UV light causes a marked change in the C═O stretching band of the film of 2C18DAC mixed with cinnamic acid, indicating that the acid is changed into the dimeric form.

Infrared assignments (4000 - 50 cm−1) are presented for the complexes [M(quinO)n](ClO4)2(quinO = quinoline N-oxide; n = 6 for Mn, Co, Ni; n = 5 for Zn, and n = 4 for Cu) and their perdeuterated analogues. The spectra are consistent with octahedral structures for the 6-coordinate complexes, a trigonal bipyramidal structure for the Zn(II) complex and a square planar structure for the Cu(II) complex, with some distortion from idealised symmetry evident for each complex. In the Mn(II) complex, strong coupling occurs between the vM-O of lowest frequency and the ligand vibration, xN-O (mode 45). In the Cu(II) complex, the single vCu-O is strongly coupled with the ring torsion (mode 28).

In view of their easy preparation, the physicochemical properties of a series of highly fluorinated cationic (ammonium salts), zwitterionic (carboxybetaines) or nonionic (amine oxide) surfactants derived from perfluoroalkylated tertiary amines were investigated. Their solubility in water, interfacial properties and the exceptionally low hemolytic activity of the zwitterionic series mark them out as potential surfactants or co-surfactants for the preparation of fluorocarbon emulsions and other preparations for biomedical use. Fine and moderately concentrated fluorocarbon emulsions (50 w/w% in fluorocarbon) could be obtained in some cases when they were used as the sole surfactant. However, none was found suitable for preparing concentrated emulsions (90 w/v% in fluorocarbon) and no appreciable stabilization was found when they were used as co-surfactants with egg yolk phospholipids.

The synthesis of two novel spin labeled 2′-deoxyuridine analogs is described. The nucleic acid building block is substituted in position 5 with a short methylamino tether, which bears either a six- or five-membered nitroxide ring.

Non-aromatic amine oxides are widely known and used compounds. A great number of amine oxides occurring in nature, or prepared synthetically, are biologically active compounds (antimetabolites and chemotherapics, cancerostatic compounds, etc.). From seven series of newly synthesized amine oxides (63 compounds), 1-alkylperhydroazepine N-oxides (PHNO) and 1-alkylpiperadine N-oxides (PINO) have been chosen for further investigation. The effects of 8 derivatives of PHNO and 8 derivatives of PINO on state 3 and 4 respiration of Ehrlich ascites mitochondria (EAM) have been studied. Derivatives with longer side-chain significantly affected respiration of EAM according to the substrates used. To elucidate the mode of action, the most potent amine oxides from each series, 1-tetradecylperhydroazepine N-oxide (tPHNO) and 1-pentadecylpiperidine N-oxide (pPINO) have been chosen for further study. Both amine oxides stimulated state 4 respiration with glutamate-malate and succinate as substrates. The effect on state 3 respiration depended on the substrates used. Both tPHNO and pPINO were able to release respiration of EAM previously inhibited by oligomycin, both decreased the level of ATP in EAM. ATPase activity was significantly stimulated by both drugs only in higher concentrations. A possible mode of action of amine oxides on oxidative phosphorylation and the relationship between chemical structure are discussed.

1. The biotransformation of [1-14C]dodecyldimethylamine oxide (DDAO) was studied in rats, rabbits and humans. 2. Metabolites eliminated in 0-24 h urine after oral dosing were separated by cation exchange chromatography into at least ten separate peaks for each species. Several prominent urinary metabolites were identified using reverse isotope dilution, g.l.c.-mass spectrometry and n.m.r. 3. Metabolite structures suggested metabolic pathways that included omega, beta-oxidation of the aliphatic chain, amine oxide reduction, and aliphatic mid-chain hydroxylation. 4. Comparison was made of the 0-24 h urinary metabolites from males of each species. N,N-Dimethyl-4-aminobutyric acid and its N-oxide accounted for 28% of the dose in humans, 28% in rabbits and 23% in rats. These species excreted 44, 51 and 60% of the dose, respectively, in 24 h. Therefore, humans and rabbits were more efficient than rats in degrading the alkyl chain to compounds containing four-carbon acids. In contrast to rabbits and humans, rats excreted greater than 12% of the dose as long-chain compounds. At least half of these compounds were C-hydroxylated amino-alcohols. 5. Under the conditions employed, the rabbit more closely approximates the metabolism of DDAO by human than does the rat.

Carbotn-13 NHR assignment of eight N-(2,4- dinitrophenyl) amines was achived. She six corresponding N- Oxides and their thermal rearr-angement products were also analyzed. The N-oxidation effect on the carbon-13 chemical shift is discussed.

The extraction of uranium(VI) by two amine oxides, 4-(5-nonyl)pyridine oxide and trioctylamine oxide has been studied. The extraction behavior of these two N-oxides is compared. The dependence of extraction on the type of amine oxide and acid, nature of organic diluent, and amine oxide concentration has been investigated. The influence of the concentration of the metal and salting-out agents is described. The possible mechanism of extraction is discussed in the light of the results of extraction isotherms, loading radiodata, and log-log plots of amine oxide concentration vs distribution ratio. The separation factors for a number of metal ions are reported, and the separation of uranium from some fission product elements has also been achieved.

The carbon-13 chemical shifts of seven N-(4-substituted phenyl) piperidine; the corresponding N-oxides, and their thermal rearrangement products were analyzed and assigned. The N-oxidation effect on the carbon-13 chemical shift is discussed, a correlation of N-oxidation effect with substituent constant (σp, σm, σI and σR) has been studied; dual substituent-parameter equation produce better correlation.