Sar atov Fall Meeting 2015

1. Saratov Fall Meeting 2015 OPTICAL PROPERTIES OF CHITOSAN IN AQUEOUS SOLUTIONS OF L- AND D-ASCORBIC ACIDS Olga N. Malinkina*1,2, Anna B. Shipovskaya1,2, Olga F. Kazmicheva2 Olga-Malinkina@yandex.ru  1 -Institute of Chemistry, Saratov State University 2 - Research and Education Institution of Nanostructures and Biosystems, Saratov State University

2. Abstract For 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.

3. FACTORS INFLUENCING on the OPTICAL ACTIVITY for Low Molecular Substances Quantum-mechanical theory of optically isotropic and anisotropic media for Macromolecular Substances Semi-empirical methods of calculation Optical purity Concentration Temperature Nature of the solvent Wavelength The configuration of a chiral center • INTERFERENCE of the CHIRAL • CENTERs of the CHAINs •    CHAIN CONFORMATION • (MOLECULAR STRUCTURE) •    STEREOREGULARITY • (COPOLYMERS)

4. Properties of CHITOSAN (Chs) • Biospecificity • Optical activity • Biocompatibility • The ability to form polyelectrolyte complexes • Antioxidant properties

5. Pharmacopeia ACID - SOLVENTS * *

6. Specific Optical Rotation of Solutions Biot’s Law (deg·ml·dm-1·gram-1) or (deg·cm2·decagram-1) α – measured angle of optical rotation of the solution, degree α0 – measured angle of optical rotation of the solvent, degree Сп – polymer concentration in solution, g/dl l– pathlength, dm 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.

7. ORD Curves of Chitosan in Solutions of Optical Isomers of Ascorbic Acid (Asc A) Chitosan solution in D-ascorbic acid L - ascorbic acid λ, nm D - ascorbic acid λ, nm Chitosan solution in L-ascorbic acid

8. ORD Curves of Chitosanin Solutions of Optical Isomers of Asc A in different molar relationships chitosan : ascorbic acid 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 λ, nm

9. Averaged Curves ORD of Chitosan Solution СChs=0.3 g/dl СAcid=1.0 – 10.0 g/dl In the Ascorbic Acid = +93 λ, nm In the Succinic Acid = – 14 In the Lactic Acid = – 23

10. Conclusions • Optical properties of solutions of CHs in ascorbic, lactic and succinic acids were studiedby 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.