- Chirality-controlled syntheses of double-helical Au nanowires
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The selective large-scale syntheses of noble metal nanocrystals with complex shapes using wet-chemical approaches remain exciting challenges. Here we report the chirality-controllable syntheses of double-helical Au nanowires (NWs) using chiral soft-templates composed of two organogelators with their own active functions; one organogelator serves to introduce helicity into the template and the other acts as a capping agent to control the Au shape. One-dimensional twisted-nanoribbon templates are prepared simply by mixing the two organogelators in water containing a small amount of toluene, followed by the addition of LiCl; template chirality is controlled through the selection of the handedness of the helicity-inducing organogelator. Double-helical Au NWs synthesized on these chiral templates have the same helical structure as the template because the Au NWs grow along both edges of the twisted nanoribbons with right- or left-handed helicities. Dispersions of the right- and left-handed double-helical Au NWs exhibit opposite CD signals.
- Nakagawa, Makoto,Kawai, Takeshi
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- Influence of chirality on the modes of self-assembly of 12-hydroxystearic acid in molecular gels of mineral oil
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The gelating abilities of enantiopure, racemic, and different enantio-enriched mixtures of 12-hydroxystearic acid (12HSA) have been compared in order to clarify conflicting reports in the literature (1) concerning their ability to gelate organic liquids. Less than 1.0 wt % of optically pure (D)-12HSA was found to gelate mineral oil. The gel matrix was comprised of high aspect ratio fibers in which the 12HSA molecules were organized as head-to-head dimers and the 12-hydroxyl groups formed an H-bonding network along the axis transverse to the longitudinal growth. Below 2 wt %, racemic 12HSA in mineral oil did not reach the percolation threshold. Its organogels were comprised of platelet-like crystals with a molecular arrangement of single, in-plane, hydrogen-bonded acyclic dimers that prevent longitudinal growth and limit the ability of the polar groups to phase separate during nucleation.
- Grahame, Douglas A. S.,Olauson, Caitlin,Lam, Ricky S. H.,Pedersen, Tor,Borondics, Ferenc,Abraham, Shibu,Weiss, Richard G.,Rogers, Michael A.
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- Cyclic fatty acyl glycosides in the glandular trichome exudate of Silene gallica
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Chemical investigation of the glandular trichome exudate from Silene gallica L. (Caryophyllaceae) resulted in isolation of 10 cyclic fatty acyl glycosides (gallicasides A-J). The cyclic structures were characterized by a glycosidic linkage of the glucose moiety to either the C-12 or the C-13 position of the octadecanoyl moiety, and by an ester linkage between the C-2 hydroxy group of the glucose moiety and the carboxyl group of the oxygenated octadecanoic acid. The structures of the cyclic fatty acyl glycosides were further distinguished from one another by acetylation and/or malonylation on the glucose moiety. Of these compounds, the 1,2′-cyclic ester of 12(R)-(6-O-acetyl-3-O-malonyl-β-d-glucopyranosyloxy)octadecanoic acid (gallicaside J) was the most abundant (30.7%). These secondary metabolites were found specifically in the glandular trichome exudate rather than in other aerial parts.
- Asai, Teigo,Fujimoto, Yoshinori
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- A General Approach to Intermolecular Olefin Hydroacylation through Light-Induced HAT Initiation: An Efficient Synthesis of Long-Chain Aliphatic Ketones and Functionalized Fatty Acids
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Herein, an operationally simple, environmentally benign and effective method for intermolecular radical hydroacylation of unactivated substrates by employing photo-induced hydrogen atom transfer (HAT) initiation is described. The use of commercially available and inexpensive photoinitiators (Ph2CO and NHPI) makes the process attractive. The olefin hydroacylation protocol applies to a wide array of substrates bearing numerous functional groups and many complex structural units. The reaction proves to be scalable (up to 5 g). Different functionalized fatty acids, petrochemicals and naturally occurring alkanes can be synthesized with this protocol. A radical chain mechanism is implicated in the process.
- Guin, Joyram,Paul, Subhasis
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p. 4412 - 4419
(2021/02/05)
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- Influence of positional isomers on the macroscale and nanoscale architectures of aggregates of racemic hydroxyoctadecanoic acids in their molecular gel, dispersion, and solid states
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Inter/intramolecular hydrogen bonding of a series of hydroxystearic acids (HSAs) are investigated. Self-assembly of molecular gels obtained from these fatty acids with isomeric hydroxyl groups is influenced by the position of the secondary hydroxyl group. 2-Hydroxystearic acid (2HSA) does not form a molecular dimer, as indicated by FT-IR, and growth along the secondary axis is inhibited because the secondary hydroxyl group is unable to form intermolecular H-bonds. As well, the XRD long spacing is shorter than the dimer length of hydroxystearic acid. 3-Hydroxystearic acid (3HSA) forms an acyclic dimer, and the hydroxyl groups are unable to hydrogen bond, preventing the crystal structure from growing along the secondary axis. Finally, isomers 6HSA, 8HSA, 10HSA, 12HSA, and 14HSA have similar XRD and FT-IR patterns, suggesting that these molecules all self-assemble in a similar fashion. The monomers form a carboxylic cyclic dimer, and the secondary hydroxyl group promotes growth along the secondary axis.
- Abraham, Shibu,Lan, Yaqi,Lam, Ricky S. H.,Grahame, Douglas A. S.,Kim, Jennifer Jae Hee,Weiss, Richard G.,Rogers, Michael A.
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experimental part
p. 4955 - 4964
(2012/07/13)
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- Method for obtaining 12-hydroxystearic acid
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Disclosed is a method for obtaining 12-hydroxystearinic acid and the salts thereof from a native fat or oil, especially ricinoleic oil, characterized in that a) the native fat or oil is hydrolized under the catalytic influence of one or several enzymes at 15-50° C. to obtain ricinoleic acid b) the glycerol thus arising and the enzyme are separated, c) the hydrolysate is catalytically hydrolized, d) the product thus obtained is formulated.
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- Cosmetic composition comprising at least one polyester resulting from esterification of at least one triglyceride of hydroxylated carboxylic acid(s) and also comprising at least one pasty compound
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Disclosed herein is a cosmetic care or makeup composition comprising a) at least one polyester resulting from esterification of at least one triglyceride of at least one hydroxylated carboxylic acid with at least one aliphatic monocarboxylic acid and with at least one aliphatic dicarboxylic acid, and b) at least one pasty compound. This composition makes it possible to obtain a deposition on a keratin materials which can be lubricious, glossy, and comfortable, can have sharply defined outlines, does not migrate, and whose color intensity can be enhanced and/or whose color retention after challenge can be enhanced.
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- Cosmetic composition comprising at least one polyester resulting from esterification of at least one triglyceride of hydroxylated carboxylic acid(s) and at least one oil with a molar mass of 650 to 10 000 g/mol
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Disclosed herein is a composition, for example, a cosmetic care and/or makeup composition for a keratin material, comprising, in a cosmetically acceptable medium, i) at least one polyester resulting from esterification of at least one triglyceride of at least one hydroxylated carboxylic acid with at least one aliphatic monocarboxylic acid and at least one aliphatic dicarboxylic acid, ii) at least one oil of a molar mass ranging from 650 to 10 000 g/mol, and iii) at least one colorant. The composition may possess cosmetic properties and can, for example, endow the makeup or care product with properties of gloss, smoothness of application and comfort. Further disclosed herein is the use of the at least one polyester and the at least one oil with a molar mass ranging from 650 to 10 000 g/mol in a physiologically acceptable composition as an agent for endowing the composition with properties of slip, gloss, comfort, definition, non-migration, enhanced color intensity and/or enhanced color retention after challenge.
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- Lysoganglioside derivatives
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Novel N-acyl-lysogangliosides obtained from gangliosides by deacyation of the ceramide group, wherein the acyl group is derived from an aliphatic acid having from 2 to 24 carbon atoms, substituted by one or more polar groups. The N-acyl-lysogangliosides of the invention exhibit an inhibiting action on protein-kinase C activation and, thus, can be utilized in therapies for various pathologies of the nervous system.
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- Electroorganic synthesis 65. Anodic homocoupling of carboxylic acids derived from fatty acids
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Fatty acid derived carboxylic acids with double bonds, hydroxy-, amino-, keto-, ester- and epoxy groups are anodically coupled to dimers (Kolbe electrolysis) in 29 to 81% yield and up to a 2.5 mol scale. Problems due to the low conductivity of fatty acid salts were overcome by the use of a flow cell with a narrow electrode gap. Fatty acids with branched alkyl chains gave dimers with interesting emulsifying properties. Dimethyl hexadecanedioate, accessible from methyl azelate, could be cyclized and further converted into homomuscone and muscone in a few steps. A commercial mixture of dimeric fatty acids (C36-dicarboxylic acids) has been coupled to give C70-diesters. Acta Chemica Scandinavica 1998. Part 64: Nielsen, M. F., Batanero, B.,.
- Weiper-Idelmann, Andreas,Aus Dem Kahmen, Martin,Schaefer, Hans J.,Gockeln, Marianne
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p. 672 - 682
(2007/10/03)
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- Properties of unusual phospholipids. III: Synthesis, monolayer investigations and DSC studies of hydroxy octadeca(e)noic acids and diacylglycerophosphocholines derived therefrom
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Diacylglycerophosphocholines containing (R)-3-, (R)-12-, (R)-17-hydroxy octadeca(e)noic acids and the corresponding racemates were synthesized and purified to homogeneity. The influence of the position of the hydroxy group on the monolayer packing properties of these fatty acids and their phosphatidylcholines was studied by Langmuir techniques and 1,2-di-[(R)-12-hydroxy-octadec-cis-9-enyl]-sn-glycero-3-phosphocholine displayed the largest lift-off area (330 A2/molecule). This result was in line with the thermotropic phase behavior of these phospholipids, as measured by differential scanning calorimetry (DSC): the gel- to liquid-crystalline phase transition temperature (T(m))passed through a minimum of -15.1°C for 1,2-di-[(R)-12-hydroxy-octadec-cis-9-enyl]-sn-glycero-3-phosphocholine.
- Negelmann, Lars,Pisch, Sandra,Bornscheuer, Uwe,Schmid, Rolf D.
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p. 117 - 134
(2007/10/03)
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- SYNTHESIS OF 2-ALKYLCYCLODODECANONE AND 12-HYDROXYSTEARIC ACID
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Cyclododecanone adds readily to C6-C10 1-alkenes with the formation of the corresponding 2-alkylcyclododecanones.The reaction takes place by a radical-chain mechanism in the presence of tert-butyl peroxide.The method was used to increase the length of the hydrocarbon chain in the synthesis of 12-hydroxystearic acid by the Baeyer-Villiger method.
- Tanchuk, Yu. V.,Kotenko, S. I.,Rozhenko, A. B.
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p. 695 - 698
(2007/10/02)
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- SYNTHESIS OF 12-HYDROXYCARBOXYLIC ACIDS FROM 11-CYANOUNDECANOIC ACID
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The synthesis of 12-hydroxy carboxylic acids with the general formula CH3(CH2)n.CHOH.(CH2)10COOH, where n = 1, 3, 5, and 7, was realized from 11-cyanoundecanoic acid and organoaluminium compounds.
- Zakharkin, L. I.,Guseva, V. V.,Churilova, I. M.
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p. 1632 - 1634
(2007/10/02)
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- An Asymmetric Synthesis of Acyclic and Macrocyclic α-Alkyl Ketones. The Role of (E)- and (Z)-Lithioenamines
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Metalation and alkylation of chiral imines derived from C10, C12, and C15 cyclic ketones gave, under kinetic metalation conditions, 2-alkylcycloalkanones of absolute configuration opposite to that formed from thermodynamic metalation.Thus, (S)-(-)-2-methylcyclododecanone is formed kinetically in 60percent ee, whereas (R)-(+)-methylcyclododecanone is reached in 80percent ee under thermodynamic conditions.In a similar fashion, acyclic ketones 20, via their chiral imines 17, are alkylated enantioselectively under both kinetic and thermodynamic modes.The kinetic metalation gives exclusively the (Z)-lithioenamines (19), while reflux of this lithio anion gives only the (E)-lithioenamine (19).Chiral α-substituted ketones are produced in 18-97percent ee.
- Meyers, A. I.,Williams, Donald R.,White, Steven,Erickson, Gary W.
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p. 3088 - 3093
(2007/10/02)
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- SYNTHESIS OF 12- AND 13-HYDROXYSTEARIC ACIDS FROM 1,5,9-CYCLODODECATRIENE
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A method was developed for the synthesis of 12-hydroxystearic acid on the basis of the reaction of 11-cyanoundecanal and 11-cyanoundecadienal, obtained from 1,5,9-cyclododecatriene and cyclododecene, with C6H13MgCl followed by alkaline hydrolysis of the nitrile group. 13-Hydroxystearic acid was obtained by hydrogenation of 13-oxostearic acid, which was synthesized from 1-N-morpholinocyclododecene and caproyl chloride.
- Zakharkin, L. I.,Guseva, V. V.,Churilova, I. M.,Maskaev, A. K.,Kobilinskaya, I. F.,Tanchuk, Yu. V.
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p. 1534 - 1536
(2007/10/02)
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