1. SPECTROSCOPIC OF THE FORMATION OF ASSOCIATE BETWEEN IN MICRO
Marta Szymula, Stanisław Radzki*,
Department of Radiochemistry
*Department of
M. Curie-Skłodowska University,

2. INVESTIGATION EQUILIBRIUM VITAMIN C AND VITAMIN E EMULSIONS
Edyta Mazur and Urszula Kubić
and Colloid Chemistry
Inorganic Chemistry
M.C. Skłodowska Sq. 2, Lublin, Poland

3. PURPOSE
The main purpose of our studies included examination
of association of water-soluble antioxidant ascorbic acid (vitamin C, H2A, AA) and hydrophobic α-tocopherol (α-T) in microemulsions.
It was found that activity of antioxidants depends not only on their molecular structure but also on the reaction environment.
We chose microemulsion as a medium of antioxidants activity studies, having in mind the fact that many substances of hydrophilic and hydrophobic character (e.g. antioxidants) can be solved or solubilized in such a systems.
We also took into account the idea that the design of microscopic molecular assemblies which mimic the microenvironment present in the biological systems can contribute a great deal to the understanding of naturally occurring processes.

4. REACTIVE FORMS OF OXYGEN (ROS)
NAME
SYMBOL
Tlen singlet 2 1 O
Radical alkoxy RO
Ozon 3
Radical peroxide
ROO
Radical
hydroxyperoxide
(=radical anion ) - OH
Peroxide
(=hydroxyperoxide)
ROOH
Radical anion
peroxide
Oxygen dioxide H
Radical hydroxyl
The most reactive chemical creature
Radiationion
Ultrasounds
Smoke of cigarette

5. L-dehydroascorbic acid
VITAMIN C OXIDATION REACTION
L-ascorbic acid
L-dehydroascorbic acid
The absorption spectrum of L-ascorbic acid dissolved in water at pH 2.0 reveals a λmax
of 243nm (ε=10000 L mol-1 cm-1) which undergoes a red shift to 265nm (ε= L mol-1 cm-1) when pH goes up to 7.0 as a result of ionization of the C-3-OH proton.

6. -TOCOPHEROL, VITAMIN E FAT-SOLUBLE VITAMIN
The activity of the E-vitamers is associated with the phenolic hydroxy group, which readily undergoes oxidation.

7. -TOCOPHEROL OXIDATION REACTION
α-Tocopherol oxidation by strong oxidizers leads to chroman-5,6-chinon
α-Tocopherol oxidation by week oxidizers leads to α-tokopherylo-p-chinon

8. MEMBRANE CELL MODEL SOLUBILIZATION
D. Chiras, Human Biology
SOLUBILIZATION
Microemulsions and liquid crystals are
the most popular delivery systems for functional cosmetics and pharmaceutical ingredients. Aggregated systems of self-assembling molecules are able to prevent chemical degradation of the active ingredient.
Solubilization – the bringing into solution of insoluble organic substances be surfactant solution above cmc. The process involves incorporation of solubilizate into the surfactant micelle.

9. ANTIOXIDANTS OF VARIOUS HYDROPHILIC/HYDROPHOBIC CHARAKTER
VITAMIN C
H2O
OIL
H2O
VITAMIN E
H2O
H2O
H2O

10. L-Ascorbic acid is easily dissolved in the microemulsion region of SDS, pentanol, water system

11. CALCULATIONS OF EQUILIBRIUM CONSTANTS FOR α-TOCOPHEROL
BINDING TO ASCORBIC ACID

12. Solution composition System K [L·mol-1]
The values of the association constants K [L mol-1] for ascorbic acid with α-tocopherol associates in various microemulsions
Solution composition
System
K [L·mol-1]
6% SDS, 1% pentanol
93% water
O/W
λ 264 nm; ±16%
λ 246 nm; ±24%
6% SDS, 22% pentanol
72% water
bicontinous
λ 264 nm; ±37%
λ 250 nm; ±30%
6% SDS, 77% pentanol
17% water
W/O
λ 264 nm; ±6%
λ 250 nm; ±7%

13. CONCLUSIONS
α-Tocopherol forms 1:1 molecular complexes with ascorbic acid, which appears to be due to the hydrogen bond.
The associate formed were decomposed with time.
Evolution of absorption spectra during the study of molecular complex formation goes in three steps through well-defined isosbestic points.
The association constants were calculated using the curve-fitting procedure.

15. Consuming more antioxidants helps provide the body with tools to neutralize harmful free radicals.