Technology for obtaining melanin from the shells of horse chestnut (Aesculus hippocastanum L.), studying its composition

Institute of Bioorganic Chemistry Academy of Sciences of the Republic of Uzbekistan, 100125, Tashkent, Uzbekistan

^* Corresponding author: luiza8181@mail.ru

Abstract

The article presents the results of a study on the development of technology for obtaining and studying the physicochemical characteristics of melanin isolated from the seed shells of horse chestnut (Aesculus hippocastanum L.), growing in the territory of Tashkent. A technological scheme for the production of melanin has been developed, which includes the stages of grinding the raw material (shell), the use of ultrasound in an ethyl alcohol environment, extraction, 3 times acidification with a solution of hydrochloric acid, filtration, concentration, dissolution in an alkali solution, precipitation, purification with ethyl acetate, dialysis, and melanin drying. The influence of the raw material-extractant ratio, multiplicity, and duration of extraction on the yield of melanin was studied and the optimal conditions for melanin isolation were determined. Melanin obtained from the shells of horse chestnut seeds is a brown powder, the yield was 24.5% by weight of dry raw materials. Analysis of the elemental composition showed: that the nitrogen content in the isolated melanin molecule is 0.7%, the amount of carbon is 44%, and hydrogen is 6%. IR spectral analysis of the melanin content in the shells of horse chestnut seeds showed the presence of absorption bands that correspond to melanin.