Glycerophosphoethanolamines
with α-branched fatty acids were synthesized, varying the side-chain length. Differential
scanning calorimetry and X-ray diffraction were applied to investigate the influence of the chemical alteration
on the physico-chemical parameters and the structures formed in lipid–water dispersions. The results show that
the introduction and stepwise elongation of side-chains decrease the transition temperature from gel
to liquid-crystalline phases. The
Tm values pass through a minimum and increase slightly on going to the triple-chain
lipid. The change in the transition parameters is connected with a modified polymorphism. Short side-chains
induce a tilt in the gel state and the elongation of the branch leads to interdigitated gel phases. With increasing
side-chain length, non-lamellar liquid-crystalline phases are stabilized. For the
long-branched derivative,
an interdigitation
of head-groups from adjacent bilayers is proposed.
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。