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Saratov Fall Meeting 2015
OPTICAL PROPERTIES
OF CHITOSAN IN AQUEOUS SOLUTIONS
OF L- AND D-ASCORBIC ACIDSOlga N. Malinkina*1,2, Anna B. Shipovskaya1,2, Olga F. Kazmicheva2
1 - Institute of Chemistry, Saratov State University2 - Research and Education Institution of Nanostructures and Biosystems,
Saratov State University
AbstractFor most biologically active compounds there is
a close correlation between biological activity and their spatial structure, which is used to establish by
the optical methods, in particular spectropolarimetry, based on the phenomenon of optical isomerism.
In this study optical activity of chitosan solutions in different solvents by spectropolarimetric method
was investigated. It was found that the spectra of optical rotation of chitosan solutions in ascorbic acid in significantly
different in magnitude and sign from chitosan solutions in other solvents.
for Low Molecular Substances
Quantum-mechanical theory of optically isotropic and anisotropic
media
for Low Molecular Substances
Quantum-mechanical theory of optically isotropic and anisotropic
media
for Macromolecular Substances
Semi-empirical methods of calculation
for Macromolecular Substances
Semi-empirical methods of calculation
Optical purity Concentration TemperatureNature of the solvent WavelengthThe configuration of a chiral center
INTERFERENCE of the CHIRAL CENTERs of the CHAINs CHAIN CONFORMATION (MOLECULAR STRUCTURE)
STEREOREGULARITY (COPOLYMERS)
33
44
• Biospecificity• Optical activity• Biocompatibility• The ability to form polyelectrolyte complexes• Antioxidant properties
• Biospecificity• Optical activity• Biocompatibility• The ability to form polyelectrolyte complexes• Antioxidant properties
FormulaStructural formula
М,at. un.
Identification, using рК
L-Ascorbic Acidγ-lactone 2,3-
dihydro-L-gulonic acid CC66HH88OO66
176Е300
antioxidant
4.111.8
+23
D-Ascorbic Acidγ-lactone 2,3-
dihydro-D-gulonic acid
–23
D-Lactic Acidα-hydroxy-
propionic acidCC33HH66OO33 90
Е270preservative
3.8 –2.6
Succinic Acidethan-1,2-
dicarboxylic acidCC44HH66OO44 118
Е363antioxidant
4.25.6
−
55
*
*
(deg·ml·dm-1·gram -1) or
(deg·cm2·decagram -1)
α – measured angle of optical rotation of the solution, degreeα0 – measured angle of optical rotation of the solvent, degree
Сп – polymer concentration in solution, g/dl
l – pathlength, dm
Biot’s Biot’s Law Law
66
The spectra of the optical activity of the solutions were recorded on an automatic
spectropolarimeter PolAAr 3001 by Optical Activity Ltd (GB) in the wavelength range
λ = 365-589 nm in a thermostated cell at 25°C.
L - ascorbic acidL - ascorbic acid
D - ascorbic acidD - ascorbic acid
Chitosan solution in D-ascorbic acidChitosan solution in D-ascorbic acid
Chitosan solution in L-ascorbic acidChitosan solution in L-ascorbic acid
77
λ, nm
λ, nm
λ, nm
in different molar relationships chitosan : ascorbic acid
88
1 - Chs : L-Asc A= 1 : 2 2 - Chs : L-Asc A= 1 : 1 1 - Chs : L-Asc A= 1 : 2 2 - Chs : L-Asc A= 1 : 1
1’ - Chs : D-Asc A= 1 : 2 2’ - Chs : D-Asc A= 1 : 1 1’ - Chs : D-Asc A= 1 : 2 2’ - Chs : D-Asc A= 1 : 1
СChs = 0.3 g/dlСAcid = 1.0 – 10.0 g/dl
In the Ascorbic AcidIn the Ascorbic Acid
In the Succinic AcidIn the Succinic Acid
In the Lactic AcidIn the Lactic Acid
= +93
= – 14
= – 23
99
λ, nm
Conclusions
• Optical properties of solutions of CHs in ascorbic, lactic and succinic acids were studied by method of ORD.
• The essential differences in the values of specific optical rotation of chitosan solution in different solvents were found.
• Values of specific optical rotation [α] 25λ for the chitosan solution in
ascorbic, lactic acid succinic acids were +93, -23 and -14 respectively.• The no essential differences in the values of specific optical rotation of
chitosan solution in L- and D-ascorbic acids were found.• The influence of molar ratio on the optical activity [α] of chitosan
solution of ascorbic acid was found.• The interaction between chitosan and ascorbic acid is spatial different
from interaction with other organic and nonogranic acids.• Perhaps this explains the synergistic effect high therapeutic action of
multicomponent systems based on chitosan and ascorbic acid.
