title: Alkylglucosides with isoprenoid-type hydrophobic chains-effects of hydrophobic chain size on the aqueous phase behavior.
abstract: Aqueous phase diagrams were constructed for two new alkylglucosides with isoprenoid-type hydrophobic chains, viz. 1-O-beta-(3,7-dimethyloctyl)-D-glucopyranoside, beta-Glc(Ger), and 1-O-beta-(3,7,11,15-tetramethylhexadecyl)-D-glucopyranoside, beta-Glc(Phyt). In a low concentration regime, from 0.17 to 34 wt.% beta-Glc(Ger), the beta-Glc(Ger)/water system exhibits two phase, a dilute (L1dil) and a concentrated isotropic phase (L1con), coexistence region. Above about 62 wt.% beta-Glc(Ger), an Lalpha phase is formed. The extent of the L1dil + L1conc two-phase region decreases as temperature increases and totally disappears above 130 degrees C, exhibiting an upper critical temperature. The beta-Glc(Phyt)/water system exhibits an Lalpha phase above 78 wt.% surfactant below which, an Lalpha + water two-phase region appears. One notable feature of these compounds is their low values of Krafft-eutectic temperature, TK, e.g. the value of TK for beta-Glc(Phyt) is below 0 degrees C although the total number of carbon atoms in the hydrophobic chain is as large as 20.
authors.affiliation: Nanotechnology Research Institute, AIST 1-1-1-Higashi, Tsukuba-Central-5, Ibaraki 305-8565, Japan.
authors.forename: Rajesh A
authors.initials: RA
authors.lastname: Salkar
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Minamikawa
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Hato
mesh_terms: D002152:Calorimetry, Differential Scanning; D005960:Glucosides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D008968:Molecular Conformation; D012995:Solubility; D014961:X-Ray Diffraction
chemical_list: D005960:Glucosides; D008051:Lipid Bilayers