Structures and phase transitions in aqueous dispersions of branched-chain glycerophosphoethanolamines
摘要:
通过改变侧链长度,合成了具有 α-支链脂肪酸的甘油磷乙醇胺。应用差示扫描量热法和 X 射线衍射法研究了化学变化对物理化学参数和在脂水分散体中形成的结构的影响。结果表明,侧链的引入和逐步拉长降低了从凝胶到液晶相的转变温度。Tm值通过一个最小值,并在进入三链脂质时略有上升。转变参数的变化与改变的多态性有关。短侧链会导致凝胶态的倾斜,而分支的拉长则会导致相互咬合的凝胶相。随着侧链长度的增加,非胶束液晶相得到稳定。对于长支链衍生物,提出了相邻双分子层的头基团相互咬合的观点。
Structures and phase transitions in aqueous dispersions of branched-chain glycerophosphoethanolamines
摘要:
通过改变侧链长度,合成了具有 α-支链脂肪酸的甘油磷乙醇胺。应用差示扫描量热法和 X 射线衍射法研究了化学变化对物理化学参数和在脂水分散体中形成的结构的影响。结果表明,侧链的引入和逐步拉长降低了从凝胶到液晶相的转变温度。Tm值通过一个最小值,并在进入三链脂质时略有上升。转变参数的变化与改变的多态性有关。短侧链会导致凝胶态的倾斜,而分支的拉长则会导致相互咬合的凝胶相。随着侧链长度的增加,非胶束液晶相得到稳定。对于长支链衍生物,提出了相邻双分子层的头基团相互咬合的观点。
Phosphatidylcholines containing an alpha-branched palmitic acid ester linked to position C2 of the glycerol backbone were synthesized and characterized using differential scanning calorimetry and X-ray diffraction, As the length of the sidegroup substituted on the palmitic acid chain is changed, the calorimetric parameters pass through a minimum. The polymorphic behaviour is different when the sidegroup is larger, or smaller, than propyl. The comparison of the physicochemical parameters of isomers differing in the bonding of the branched chain fatty acid to the glycerol backbone (to position C1 or C2, respectively) shows that the chains are nonequivalent.