In this paper we study the interactions of two biomolecules (ascorbic acid and Annonacin) with a bilayer lipid membrane. Egg yolk phosphatidylcholine (eggPC) liposomes (in crystalline liquid state) were prepared in solutions of ascorbic acid (AA) at different concentration levels. On the other hand, liposomes were doped with Annonacin (Ann), a mono-tetrahydrofuran acetogenin (ACG), which is an effective citotoxic substance. While AA pharmacologic effect and action mechanisms are widely known, those of Ann’s are only very recently being studied.

Both Fourier Transformed Infrared (FTIR) and Raman spectroscopic techniques were used to study the participation of the main functional groups of the lipid bilayer involved in the membrane-solution interaction. The obtained spectra were comparatively analyzed, studying the spectral bands corresponding to both the hydrophobic and the hydrophilic regions in the lipid bilayer. Electrochemical experiments namely; impedance spectroscopy (EIS) and cyclic voltamperometry (CV) were used as the main characterization techniques to analyse stability and structural changes of a model system of supported EggPC bilayer in connection with its interactions with AA and Ann.

At high molar ratios of AA, there is dehydration in both populations of the carbonyl group of the polar head of the lipid. On the other hand, Ann promotes the formation of hydrogen bonds with the carbonyl groups.

No interaction between AA and phosphate groups is observed at low and intermediate molar ratios. Ann is expected to be able to induce the dehydration of the phosphate groups without the subsequent formation of H bonds with them.

According to the electrochemical analysis, the interaction of AA with the supported lipid membrane does not alter its dielectric properties. This fact can be related to the conservation of structured water of the phosphate groups in the polar heads of the lipid. On the other hand, the incorporation of Ann into the lipid membrane generates an increase in the number of defects while changes the dielectric constant. This, in turn, can be associated with the induced dehydration of the phosphate groups.

在本文中，我们研究了两种生物分子（抗坏血酸和Annonacin）与双层脂质膜的相互作用。在不同浓度水平的抗坏血酸（AA）溶液中制备蛋黄磷脂酰胆碱（eggPC）脂质体（呈结晶液态）。另一方面，脂质体中掺入了Annonacin（Ann），Annonacin（Ann）是一种单四氢呋喃产乙酸原（ACG），是一种有效的毒物。虽然机管局的药理作用和作用机制广为人知，但安氏的药理作用和作用机制才刚刚被研究。

傅里叶变换红外（FTIR）和拉曼光谱技术都用于研究参与膜-溶液相互作用的脂质双层主要功能基团的参与。对获得的光谱进行比较分析，研究与脂质双层中的疏水和亲水区域相对应的光谱带。电化学实验即；阻抗谱（EIS）和循环伏安法（CV）被用作主要表征技术，以分析受支持的EggPC双层模型系统与AA和Ann的相互作用的稳定性和结构变化。

在AA的高摩尔比下，脂质极性头的两个羰基基团中都存在脱水。另一方面，安促进与羰基的氢键的形成。

在低和中等摩尔比下，没有观察到AA和磷酸基团之间的相互作用。预期Ann能够诱导磷酸基团的脱水而不会随后与它们形成H键。

根据电化学分析，AA与负载的脂质膜的相互作用不会改变其介电性能。这个事实可能与脂质极性头中磷酸基团的结构化水的保守性有关。另一方面，将Ann结合到脂质膜中会增加缺陷数量，同时改变介电常数。反过来，这可能与磷酸基团的诱导脱水有关。