Improvement of the method for isolating cholesterol from animal brain tissue

Scientific research results in pandemic conditions (COVID-19)

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formed and they will have more memory opportunities in relation to
learning activities.

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Oshchepkova Julia Igorevna, Doctor of Chemical Sciences, Head of the

Laboratory of Protein and Peptide Chemistry, Institute of Bioorganic

Chemistry, Uzbekistan

Abdullaev Bayat Fattakhovich, Junior Researcher, Institute of Bioorganic

Chemistry, Uzbekistan

Khudoyberdiev Tokhir Alisherovich, Research intern, Institute of

Bioorganic Chemistry, Uzbekistan

Zhabbarov Zhamshid Tuychievich, Junior Researcher, Institute of

Bioorganic Chemistry, Uzbekistan

IMPROVEMENT OF THE METHOD FOR ISOLATING CHOLESTEROL FROM

ANIMAL BRAIN TISSUE

J. Oshchepkova, B. Abdullaev, T. Khudoyberdiev, Zh. Zhabbarov

Abstract: Cholesterol and its derivatives are used in the production of

liquid crystals, in pharmacology as a component of dosage forms and
diagnostic tools, as a precursor to steroid drugs. Cholesterol in the
composition of the cell plasma membrane plays the role of a bilayer
modifier, giving it a certain stiffness due to an increase in the density of the
"packing" of phospholipid molecules. In this work, an improvement is made
in the technology for producing cholesterol from biological material.

Keywords: phosphosolipids, cholesterol, drugs.

Scientific research results in pandemic conditions (COVID-19)

85

When using cholesterol as a component of some diagnostic kits, the

absence of phospholipid impurities in the preparation plays an important
role. In the proposed method, the purity of the cholesterol obtained is
achieved by treating cholesterol with aluminum oxide, which irreversibly
sorb all anionic impurities.

Bull brains were ground in a blender in the presence of ethanol in a ratio

of 1: 2.5 and filtered. The resulting pasty mass was distributed in a thin layer
on a plastic film and dried for several days. The dry product was pulverized
and repeatedly (4-5 times) was extracted with acetone. The collected and
combined extracts were evaporated to 500 ml and stored in a cold place. The
precipitate formed was filtered off, suspended in a 5% solution of sodium
hydroxide in alcohol and refluxed. The resulting precipitate was washed
with 80% alcohol and dissolved in 2-3 volumes of acetone.

The resulting mixture was applied onto an alumina column, eluting with

acetone, periodically checking the effluent for the presence of cholesterol by
thin layer chromatography (TLC).

Fractions containing cholesterol were combined and evaporated. The

solution was stored in a refrigerator at ‒ 40°C to form a precipitate
containing cholesterol, the next day it was filtered off and dried in air. The
resulting product was checked by TLC in the presence of a standard sample
in the hexane-ethyl acetate system (3:1). Melting point - 148°C.

It is determined that the improvement of the extraction technology

preserves the qualitative characteristics of the obtained material, which can
be used as a component for the production of dosage forms and diagnostic
tools.

Khujakulov Siyovush, PhD in Law, associate professor, doctoral student of

the faculty of postgraduate education of the Academy of the Ministry of

Internal Affairs of the Republic of Uzbekistan, Tashkent

THE NECESSITY OF SYSTEMATIZATION OF NORMATIVE DOCUMENTS ON

THE PREVENTION OF CRIME

Khujakulov S. В.

Abstract: the article substantiates the need to systematize normative

documents on the prevention of offenses, based on the results of the analysis of
scientific views of legal scientists, the practice of prevention of offenses and
normative documents. Scientific conclusions and proposals for improving
national legislation aimed at developing scientific and theoretical approaches
to these issues have been developed. Scientific conclusions were made about