- Synthesis and surface properties of alkyl β?D?thioglucopyranoside
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Alkyl thioglycosides are a class of nonionic sugar-based sulfur-containing surfactants and bioreagents. The surfactants 1,2?trans alkyl β?D?thioglucopyranosides with different alkyl chain length (n = 6–12) were stereoselectively prepared by the Helferich method. Their properties including HLB number, logP value, water solubility, foam property, emulsifying property, surface property and thermotropic liquid crystal property were mainly investigated. The results showed that their HLB numbers and water-solubility decreased as the related logP values increased with increasing the alkyl chain length. Alkyl β?D?thioglucosides were already insoluble in water with n ≥ 10. Both β?D?thioglucopyranosides (n = 8, 9) reduced the surface tension of the related aqueous solution to nearly 29 mN·m?1 at the critical micelle concentration (CMC), they also had excellent foaming ability and foam stability. Nonyl β?D?thioglucopyranoside had good emulsifying properties for both n?octane/water system and toluene/water system. Alkyl β?D?thioglucopyranosides (n = 6–12) were observed to have the thermotropic liquid crystal properties.
- Wu, Xiubing,Chen, Langqiu,Fu, Fang,Fan, Yulin,Luo, Zhiqiang
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p. 282 - 289
(2018/12/13)
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- Preparation of S-glycoside surfactants and cysteine thioglycosides using minimally competent Lewis acid catalysis
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Here we report a method for the preparation of anomerically pure β-S-glycopyranosides (1,2-trans-glycosides) from the corresponding peracetate donors. S-glycosylation was performed in CHCl3 at reflux in the presence of a catalytic amount of InBr3. Deacylation of the intermediate peracetates were achieved under Zemplén conditions. Five pyranose examples, monosaccharides D-glucose and D-galactose and disaccharides cellobiose, maltose, and lactose, were used as donors, and five thiols including an α/ω dithiol and Fmoc-L-cysteine were used as acceptors. Melting points, high res MS, [α]D and NMR data (1H and 13C, including COSY, HSQC and HMBC) are reported for compounds not previously described.
- Szabó, Lajos Z.,Hanrahan, Dillon J.,Jones, Evan M.,Martin, Erin,Pemberton, Jeanne E.,Polt, Robin
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- Synthesis, purification and liquid-crystalline behaviour of several alkyl 1-thio-D-glycopyranosides
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This paper describes the synthesis, purification, and liquid- crystalline behaviour of a series of alkyl 1-thioglycopyranosides. The synthesis of these derivatives was carried out via a Lewis acid mediated coupling of the fully acetylated monosaccharide with an alkanethiol. The choice of the Lewis acid depends on the configuration of AcO-2. The carbohydrate-derived surfactants exhibit thermotropic liquid-crystalline behaviour. The alkyl 1-thioglycopyranosides form the expected smectic A phases upon heating. The clearing temperatures vary with alkyl chain length which is in accordance with the accepted model for the S(A) phase of amphiphilic carbohydrate mesogens. For the alkyl 1-thiotalopyranosides, the clearing points are much lower than expected, presumably due to the formation of an intramolecular hydrogen bond in the talose moiety.
- Galema, Saskia A.,Engberts, Jan B. F. N.,Van Doren, Henk A.
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p. 423 - 434
(2007/10/03)
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- Non-amphiphilic carbohydrate liquid crystals containing an intact monosaccharide moiety
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A chiral rigid moiety which forms the basis of a new class of non-amphiphilic carbohydrate liquid crystals has been developed. This moiety contains a fully intact glucopyranose ring embedded in a trans-decalin structure. The original carbohydrate is substituted so that only two hydroxyl groups are left, resulting in derivatives with reduced hydrophilicity. The substituents R and X-R′ on the 4,6-O-ylidene β-D-glucopyranoside are in the equatorial position and can be varied extensively, using straightforward synthetic procedures. Investigations as to the requirements for R and X-R′ for inducing liquid-crystalline behavior have shown that at least one of the substituents should contain a large, polarizable aromatic moiety. An aromatic Schiff base fulfils this requirement.
- Smits,Engberts,Kelogg,Van Doren
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p. 185 - 199
(2007/10/02)
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- Synthesis of Alkyl-β-D-thioglucopyranosides, a Series of New Nonionic Detergents
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As a part of our search for new types of detergent useful for biological applications, a series of alkyl-β-D-thioglucopyranosides was synthesized in several steps from glucose.The overall yield was about 80percent.Critical micelle concentrations of n-hexyl-, n-heptyl-, n-octyl-, and n-nonyl-β-D-thioglucopyranoside were determined.Because of their electroneutrality, high solubility in water and high critical micelle concentration, n-heptyl- and n-octyl-β-D-thioglucopyranoside seem to be potentially useful detergents for applications in biological systems.
- Saito, Setsuo,Tsuchiya, Tomofusa
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p. 503 - 508
(2007/10/02)
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