ACADEMIC RESEARCH IN MODERN SCIENCE
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EXTRACTION OF MEDICINAL MELANIN FROM CHESTNUT SHELLS
Isakova Sh.Kh.
Normatov A.M.
Bobaev I.D.
Tashkent Institute of Chemical Technology
E mail: Sahnozai220@gmail.com Tel : +998 90 986-66-63
https://doi.org/10.5281/zenodo.14723270
Currently, a significant portion of drugs used in medical practice around the
world are based on biologically active compounds isolated from plants. Because
herbal medicines and biologically active food supplements give positive results
even with long-term use, without having a negative impact on the div. In
particular, secondary raw materials generated during the production of
medicines and biologically active supplements are of great importance in
improving the quality and biological value of food products.
Conducting scientific research to improve the technological indicators of
bakery products, which form the basis of the world diet, based on additives of
plant origin, increasing consumer safety, biological value, rheological properties
of dough and bread quality, rational use of environmentally friendly raw
materials, reducing the cost of production and their implementation in practice.
All parts of the plant, such as seeds, roots, leaves, fruits, skin, branches or
even the entire plant, can be used to prepare plant extracts for various purposes.
These plants (or fractions), rich in biologically active compounds, can be used as
drugs due to their direct or indirect therapeutic effect. These compounds
contained in plant materials generally act synergistically, preventing certain
diseases, increasing mobility or even making a significant contribution to the
treatment of certain diseases.
Chestnut (Aesculus hippocastanum L.) is a large-leaved tree, widespread
throughout the world. The common name comes from the name of the
evergreen plant Aesculus (Latin yesca - food) and is so named because of its
edible trees and fruits [1].
Chestnuts have long been widely used in folk medicine, and at present they
are beginning to be officially studied. In our republic, only the components of the
fruits of this tree have been studied as medicinal raw materials. Currently,
chestnuts are actively studied from the point of view of creating food additives
from their above-ground parts [2].
Melanins are dark-colored, high-molecular, disordered polymers formed in
organisms during the enzymatic oxidation of nitrogen-containing and nitrogen-
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free polyphenols. They have radioprotective and antioxidant properties, are
sorbents of radionuclides and heavy metals, and effectively protect living
organisms from ultraviolet radiation. Melanins are used in medicine,
pharmacology, agriculture and other fields. Melanins are obtained by chemical
synthesis technology, oxidation of the amino acid tyrosine and its derivatives,
extraction from animal and plant raw materials, and microbial synthesis using
microorganisms. Due to the variety of chemical methods for extracting melanin
from biological materials that are raw materials for its production, there is no
single standard method for their separation and purification separately [3].
The aim of this study was to isolate the medicinal substance melanin from
chestnut peel in pure form using an effective method and conduct its qualitative
analysis.
Melanin separation method. Water-soluble melanin with high antioxidant
activity was obtained from non-traditional raw materials using a
biotechnological method; crushed chestnut kernel peel was used as raw
material. A method for obtaining water-soluble melanin was developed by
carrying out a three-stage extraction of crushed chestnut kernel peel and water
in a weight ratio of 1:20, with an extraction duration of 12 hours at each stage.
The extracts obtained in three stages were combined and filtered (the volume of
the extract was 15 l). The resulting extract was evaporated until a volume of 3
liters remained. A 0.5 N NaOH solution was added to the aqueous extract until
the pH reached 12.
The resulting transparent mixture was acidified to a pH of 1.5. The resulting
mixture of precipitated melanin was extracted with ethyl acetate in a weight
ratio of 1:2 in three stages. The aqueous portion, i.e. the organic extract, was
separated from the mixture. The melanin that formed a precipitate in the
aqueous phase was separated by filtration. The melanin precipitate was
dissolved in a 12% ammonia solution until the melanin was completely
dissolved. After evaporation of the residual ammonia and water in a rotary
evaporator, the melanin solution was dried in a sublimation drying unit. At the
final stage of separation, column chromatography (6×70 cm) was used, the flow
rate of the melanin dissolved in the solvent from top to bottom was 0.028 cm/s,
the washing process was carried out in the eluate mode, the pure substance
fraction was isolated. At the next stage of the study, a chemical analysis of the
isolated melanin substance was carried out by alkaline hydrolysis.
Structural analysis of melanin. The study of the chemical composition of melanin
was mainly carried out by the method of hydrolysis with KOH solution at a high
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pressure of 1.5 atm and a high temperature of 180 °C in various concentrations,
which makes the analysis of the composition of melanin somewhat more
effective. This is the main issue that must be taken into account in the separation
and analysis of melanin, and the choice of relatively flexible reagents is of great
importance in the separation. Successive extraction of melanin present in the
aqueous extract of the culture with increasingly polar organic solvents is
effective: petroleum ether, ethyl acetate, chloroform and a mixture of
chloroform and ethanol.
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and biomarkers of alpha linolenic acid and risk of all cause, cardiovascular, and
cancer mortality: systematic review and dose-response meta-analysis of cohort
studies: // BMJ. - 2021. - Vol. 375. - Art. n 2213. doi:10.1136/bmj.n2213
2. Гасымова Ш.А., Новрузов Э.Н., Мехтиева Н.П. Изучение химического
состава жирного масла из семян Silybum marianum (L.) gaertn. Химия
растительного
сырья.
2017.
№3.
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107–111.
doi:
10.14258/jcprm.2017031585
3. Агаджанян А.Е., Оганисян Г.Д., Егиян К.И., Сагиян А.С. Технологические
особенности выделения и очистки различных классов биологически
активных веществ из ферментационных растворов // Армян. хим. журнал.
2015. 68, № 4, С. 532- 551.
