Casali Institute of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Langmuir. 2010 Mar 2;26(5):3648-53. doi: 10.1021/la903100m.
The synergistic solubilization of two major hydrophilic (vitamin C, ascorbic acid, AA) and lipophilic (vitamin E, D-alpha-tocopherol, VE) antioxidants within reverse hexagonal (H(II)) mesophases is reported. The H(II) mesophases are composed of monoolein (GMO)/VE/AA/water. A wide range of VE concentration was examined (on the expense of GMO concentrations) while the AA and water concentrations remained constant (4 and 12.5 wt %, respectively) in order to expand the H(II) mesophase. SAXS and DSC combined with ATR-FTIR techniques were utilized to study the interactions between each solubilizate and the H(II) component that enabled the synergistic accommodation of the hydrophilic and hydrophobic molecules. It was revealed that up to 27 wt % VE solubilized within the H(II) mesophase. This hydrophobic additive localized at the lipophilic GMO tail region solvating the surfactant tails, thereby enabling the formation of the H(II) structure. As a result, the lattice parameter and the melting point of the hydrophobic tails decreased. Above 27 wt % VE (up to 33 wt %), once the GMO lipophilic region was homogenously solvated, additional VE molecules located closer to the interface. At this range of concentrations, new hydrogen bonds between O-H groups of VE and O-H groups of GMO were formed. Once 35 wt % VE was introduced, the H(II) structure transformed to face-centered reverse micellar cubic phase (Fd3m, Q(227)).
两种主要亲水性（维生素 C，抗坏血酸，AA）和疏水性（维生素 E，D-α-生育酚，VE）抗氧化剂在反向六方（H（II））中间相内的协同增溶作用被报道。H（II）中间相由单油酸甘油酯（GMO）/VE/AA/水组成。考察了广泛的 VE 浓度（以牺牲 GMO 浓度为代价），同时 AA 和水浓度保持不变（分别为 4 和 12.5wt％），以扩大 H（II）中间相。利用 SAXS 和 DSC 结合 ATR-FTIR 技术研究了每种增溶剂与 H（II）组分之间的相互作用，从而使亲水性和疏水性分子能够协同容纳。结果表明，高达 27wt％的 VE 可在 H（II）中间相内增溶。这种疏水性添加剂定位于亲脂性 GMO 尾部区域，溶解表面活性剂尾部，从而形成 H（II）结构。因此，晶格参数和疏水性尾部的熔点降低。在 27wt％VE 以上（高达 33wt％），一旦 GMO 亲脂区域被均匀溶解，额外的 VE 分子更靠近界面。在该浓度范围内，VE 的 O-H 基团和 GMO 的 O-H 基团之间形成新的氢键。一旦引入 35wt％VE，H（II）结构就会转变为面心反向胶束立方相（Fd3m，Q（227））。
