Organizing co mmittee

 
 

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Poster presentation 
167 
CHEMICAL STRUCTURE OF THE POLYPHENOL 
COMPOSITION OF THE LEAVES OF PONTIAN HAWTHORN 
Crataegus pontica 
 
K.V. Raimova, N.G. Abdulladzhanovа, A.D. Matchanov 
 
Institute of Bioorganic Chemistry named after acad. A.S. Sadykov 
Academy of Sciences of the Republic of Uzbekistan, Mirzo Ulugbek str., 83, 
Tashkent, 100125 (Republic of Uzbekistan). 
 
The chemical composition (polyphenols) of the leaves of the plant 
Crataegus pontica 
K. Koch has been studied. The process of isolating polyphenols from plant raw 
materials includes several stages: extraction of raw materials, processing of the extract 
with organic solvents, evaporation, precipitation of the sum of polyphenols, 
purification. The increase in the efficiency of the use of raw materials is achieved 
mainly at the first stage – extraction. The yield of the sum of polyphenols was studied 
depending on: the composition of the extractant, the extraction modulus, the multiplicity 
of extraction, the ratio of raw materials - extractant, temperature, thickening conditions, 
treatment of the aqueous residue with organic solvents, the conditions of precipitation of 
the sum of polyphenols and their drying. As a result, optimal conditions for the isolation 
of polyphenols from plant raw materials were selected, and the found condition 
obtained the sum of polyphenols from the autumn leaves of 
Crataegus pontica 
K.Koch 
with a yield of 4.5%. Chromatographic study of the isolated fractions revealed that the 
polyphenols of the ethyl acetate fraction are mainly represented by monomeric 
catechins, flavonolams and tannins. As a result, flavan-3-ols were isolated in the 
individual state. The isolated flavan-3-ols have been identified as (+)-catechin, (-)-
epicatechin. The remaining compounds were separated on a Sephadex LH-20 column 
using chloroform-methanol in various ratios (chloroform:methanol in a ratio of 4:1) as 
an eluent, and a number of individual compounds were isolated.
Using a complex of 
physicochemical methods, including: IR spectrum, UV spectrum, 
13
C NMR, HPLC, 
mass spectrometry, the obtained product was analyzed. In this regard, the purpose of 
our work is to study the chemical composition of phenolic compounds in the leaves of 
the 
C. pontica
plant and to determine the structure of the isolated substances by 
physicochemical methods. The structures of the isolated compounds were determined 
using physicochemical methods. As a result, more than 12 polyphenols were isolated 
from the leaves of 
C. pontica
, such as quercetin-3-
O
-β-
D
-galactopyranoside 
(hyperoside), gallic acid, quercetin-3-rutinoside, 3, 5, 7, 3', 4'- pentaoxyflavone 
(quercetin), 
2-(3,4-dimethoxyphenyl)-7methoxy-3,4-dihydro-2H-chromene-3,4,5,6-
tetrol, aрigenin-6-
C
-glycoside, procyanidin B, (+)-catechin (5,7,3',4'-tetraoxyflavan-3-
ol), (-)-epicatechin (5,7,3',4'-tetraoxyflavan-3-ol), ellagic acid, 1-
O
-galloyl-4-
O
-
catechin-β-
D
-glucose and caffeic acid ester with 2,3-dihydroxyglutaric acid. From 
these, the last two substances were first isolated from this plant.