Interactions between carbon nanomaterials, including carbon dots, fullerene, carbon nanotube, graphene, and graphene oxide, and biomolecules play an important role in the field of nanobiotechnology. Due to the unique properties of carbon nanomaterials and the magnificent features of their colloids, it shows high potential in fibrillation inhibition, high sensitivity sensor fabrication, bioimaging, drug delivery, and other areas. Hereby, we will go over different families of carbon nanomaterials regarding to the interaction between carbon nanomaterials and biomolecules at the interface, and their applications will be reviewed as well.
As a result of a recent ad hoc prospection of the Algerian territory, a collection of peanut (groundnut; Arachis hypogaea L.) landraces was established, covering a remarkable array of diversity in terms of morphological and physiological features, as well as of adaptation to local bioclimatic conditions. In the present work, the oils extracted from the seeds of these landraces were evaluated in terms of edible properties and suitability for biodiesel production. As for edible use, a low free acidity (ranging from 0.62 to 1.21%) and a high oleic acid content (44.61-50.94%) were common features, although a poor stability to oxidation [high peroxide values, high spectrophotometric indices, and low % of inhibition in the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH)· test] was observed in a few cases. As for biodiesel production, low values of acidity [1.23-2.40 mg KOH (g oil)–1], low iodine values [90.70-101.54 g I2 (g oil)–1], high cetane numbers (56.95–58.88) and high calorific values (higher heating value 37.34–39.27 MJ kg–1) were measured. Edible properties and suitability for biodiesel production were discussed with respect to the German standard DIN 51605 for rapeseed oil and to the EN 14214 standard, respectively. One way ANOVA and Hierarchical Cluster Analysis showed significant differences among the oils from the Algerian peanut landraces.
We have previously reported a new preparation method for liposomes using supercritical carbon dioxide (scCO2) as a solvent, referred to as the supercritical carbon dioxide reverse phase evaporation (scRPE) method. In our previous work, addition of ethanol to scCO2 as a co-solvent was needed, because lipid molecules had to be dissolved in scCO2 to form liposomes. In this new study, niosomes (nonionic surfactant vesicles) were prepared from various nonionic surfactants using the scRPE method. Among the nonionic surfactants tested were polyoxyethylene (6) stearylether (C18EO6), polyoxyethylene (5) phytosterolether (BPS-5), polyoxyethylene (6) sorbitan stearylester (TS-106V), and polyoxyethylene (4) sorbitan stearylester (Tween 61). All these surfactants have hydrophilic-lipophilic balance values (HLBs) around 9.5 to 9.9, and they can all form niosomes using the scRPE method even in the absence of ethanol. The high solubility of these surfactants in scCO2 was shown to be an important factor in yielding niosomes without ethanol addition. The niosomes prepared with the scRPE method had higher trapping efficiencies than those prepared using the conventional Bangham method, since the scRPE method gives a large number of unilamellar vesicles while the Bangham method gives multilamellar vesicles. Polyoxyethylene-type nonionic surfactants with HLB values from 9.5 to 9.9 were shown to be optimal for the preparation of niosomes with the scRPE method.
Physicochemical properties of oil-in-water (O/W) emulsions containing fatty alcohols and surfactants have been investigated with the aim of developing new formulations that are less viscous and more transparent than conventional milky lotions, as well as for providing greater skin-improving effects. O/W-based creams can be converted to low viscosity milky lotions following their emulsification with a homogenizer at temperatures greater than the transition temperatures of their molecular assemblies (α-gel). The stability of the O/W emulsions evaluated in the current study increased as the transition temperatures of the molecular assemblies formed from their fatty alcohol and surfactant constituents increased. A decrease in the emulsion droplet size led to the formation of a new formulation, which was transparent in appearance and showed a very low viscosity. The absence of a molecular assembly (α-gel) formed by the fatty alcohol and surfactant molecules in the aqueous phase allowed for the formation of a stable transparent and low viscosity nanoemulsion. Furthermore, this decrease in droplet size led to an increase in the interfacial area of the emulsion droplets, with almost all of the fatty alcohol and surfactant molecules being adsorbed on the surfaces of the emulsion droplets. This was found to be important for preparing a stable transparent formulation. Notably, this new formulation exhibited high occlusivity, which was equivalent to that of an ordinary cosmetic milky lotion, and consequently provided high skin hydration. The nanoemulsion was destroyed following its application to the skin, which led to the release of the fatty alcohol and surfactant molecules from the surface of the nanoemulsion into the aqueous phase. These results therefore suggest that the fatty alcohol and surfactant molecules organized the molecular assembly (α-gel) and allowed for the reconstruction of the network structure.
Two crown ether surfactants, dodecanoyloxymethyl- (C11Φ6) and octanoyloxymethyl-18-crown-6 (C7Φ6), were synthesized and the surface tension dependence on surfactant concentration of their aqueous solutions was measured both in the absence and presence of alkali chlorides to confirm the critical micelle concentration (CMC) is highest for the added cation that have an ionic diameter comparable to the hole size of the crown ether ring and that several break points on the surface tension vs. concentration curves occur for these crown ether surfactants. For C11Φ6 and C7Φ6, in the absence of salt, the surface tension vs. concentration curves had two break points. Using the solubilization of a water-insoluble dye as an indicator, we found that the break point at the higher concentration (m0) for C7Φ6 was due to micelle formation. Two break points were also observed for the aqueous solution of C11Φ6 in the presence of NaCl, KCl, RbCl, and CsCl salts at concentrations of 0.22 mol kg–1 and for C7Φ6 with 0.22 mol kg–1 KCl added. The CMC (m0) was found to be the highest for solutions containing K+ salts because K+ has an ionic diameter comparable to the hole size of 18-crown-6 ring. Furthermore, the CMC decreased as the ionic diameters of the added cations deviated from the hole size. The molecular areas at two break points, estimated by the Gibbs adsorption isotherm, except for that at the break point at mI of C7Φ6, were very small for an adsorbed monolayer. Further investigation is required to elucidate the reason for the break point at mI.
In this work, novel succinic acid-type gemini surfactants containing semifluoroalkyl groups, dl- and meso-2,3-bis[Rf-(CH2)n]-succinic acids (Rf = C4F9, C6F13, C8F17; n = 2, 9), were successfully synthesized, and the effects of Rf, methylene chain length (n), and stereochemistry on their monolayer behaviors were studied. Critical micelle concentrations (CMC) of dl- and meso-2,3-bis[C4F9(CH2)9]-succinic acids were one order of magnitude smaller than that of the corresponding 1+1 type surfactant, C4F9(CH2)9COOH. From surface pressure-area (π-A) measurements, the lift-off areas of the geminis were found to decrease in the order C4F9 ≥ C6F13 > C8F17, regardless of methylene chain length and stereochemistry. The zero-pressure molecular areas of the geminis were twice those of the corresponding 1+1 type surfactants. Based on Gibbs compression modulus analysis, it was clarified that 2,3-bis[C8F17(CH2)n]-succinic gemini with short methylene chains (n = 2) would form more rigid monolayers than those having long methylene chains (n = 9). Unlike for 2,3-bis(alkyl)-succinic acids, the effects of stereochemistry on the monolayer behavior of semifluoroalkylated geminis were small.
Japan has been known as a healthy country since its life expectancy became among the highest in the world in the 1980s. The influence of the Japanese diet is one of the factors explaining Japan’s high life expectancy. Our recent study that fed representative freeze-dried and powdered Japanese diets from 1960, 1975, 1990, and 2005 based on National Health and Nutrition Research to mice showed the 1975 Japanese diet exhibited the strongest visceral fat accumulation suppression and overall health benefits. However, it is unclear why. We investigated the effects of the fatty acid composition in Japanese diets on visceral fat accumulation in mice. ICR mice were fed diets replicating the fatty acid composition and macronutrient ratios of Japanese diets from 1960, 1975, 1990, and 2005 for four weeks. The 1975 diet suppressed visceral fat accumulation and adipocyte hypertrophy. DNA microarray analysis showed the 1975 diet suppressed Acyl-CoA synthetase and prostaglandin D2 synthase mRNA expressions in white adipose tissue. As the effects of the 1975 diet are likely due to differences in fatty acid intake and/or composition, we investigated test diets that replicated only the fatty acid composition of Japanese diets. There were no significant differences in visceral fat mass. Therefore, both the quality and quantity of fatty acids are involved in the anti-obesity effects of the 1975 Japanese diet.
Choline chloride catalyzed efficient method for amidation of fatty acid methyl ester to monoethanolamide respectively. This is a solvent free, ecofriendly, 100% chemo selective and economically viable path for alkanolamide synthesis. The Kinetics of amidation of methyl ester were studied and found to be first order with respect to the concentration of ethanolamine. The activation energy (Ea) for the amidation of lauric acid methyl ester catalyzed by choline chloride was found to be 50.20 KJ mol–1. The 98% conversion of lauric acid monoethanolamide was obtained at 110°C in 1 h with 6% weight of catalyst and 1:1.5 molar ratio of methyl ester to ethanolamine under nitrogen atmosphere.
The present study describes the synthesis, characterization and evaluation of antiproliferative activity of novel diisopropylphenyl esters of alpha-linolenic acid (ALA), valproic acid (VA), butyric acid (BA) and 2-ethylhexanoic acid (2-EHA). These esters were chemically synthesized by the esterification of fatty acids with 2,6-diisopropylphenol and 2,4-diisopropylphenol (propofol). The structure of new conjugates viz. propofol-(alpha-linolenic acid) (2,6P-ALA and 2,4P-ALA), propofol-valproic acid (2,6P-VA and 2,4P-VA), propofol-butyric acid (2,6P-BA and 2,4P-BA) and propofol-(2-ethylhexanoic acid) (2,6P2-EHA and 2,4P-2-EHA) were characterized by FT-IR, NMR (1H, 13C) and mass spectral data. The synthesized conjugates having more lipophilic character were tested for antiproliferative in vitro studies on A549, MDA-MB-231, HeLa, Mia-Pa-Ca and HePG2 cancer cell lines. All the conjugates showed specific growth inhibition on studied cancer cell lines. Among the synthesized esters, the conjugates synthesized from BA, VA and 2-EHA exhibited prominent growth inhibition against A549, HeLa, Mia-Pa-Ca and HePG2 cancer cell lines. The preliminary results suggest that the entire novel conjugates possess antiproliferative properties that reduce the proliferation of cancer cells in vitro.
Chemical composition and potent odorants that contribute to the characteristic odor of essential oil from Alismatis Rhizoma (tubers of Alisma orientale) were investigated by gas chromatography-mass spectrometry (GC-MS), GC-olfactometry (GC-O), aroma extract dilution analysis (AEDA) and relative flavor activity (RFA) methods. Fifty components, representing 94.5% of the total oil, were identified. In this study, we newly identified thirty-nine compounds in the oil from tubers of A. orientale. The major constituents of the essential oil were khusinol (36.2%), δ-elemene (12.4%), germacron (4.1%), alismol (3.8%), β-elemene (3.1%), and α-bisabolol (1.9%). Through sensory analysis, sixteen aroma-active compounds were detected and the key contributing aroma-active compounds were δ-elemene (woody, flavor dilution (FD)-factor = 4, RFA = 0.3) β-elemene (spicy, FD = 5, RFA = 0.7), spathulenol (green, FD = 5, RFA = 1.0), γ-eudesmol (woody, FD = 6, RFA = 1.5), and γ-cadinol (woody, FD = 5, RFA = 1.0). These compounds are thought to contribute to the odor from tubers of A. orientale. These results imply that the essential oil from the tubers of A. orientale deserve further investigations in the phytochemical and medicinal fields.