Organizing co mmittee

 
 

---

Poster presentation 
145 
POLYSACCHARIDES OF THE AERIAL PART OF Pisum sativum 
 
R.K. Rakhmanberdyeva
1
, Z.Y. Samandarova
2
, A.E. Eshbekov
2
 
1) S.Yu. Yunusov Institute of the Chemistry of Plant Substances Academy of sciences of 
the Republic of Uzbekistan st. Mirzo-Ulugbek, 77, 100170 Tashkent 
e-mail: [e-mail] 
2) National University of Uzbekistan named after Mirzo Ulug’bek 
 
Peas - 
Pisum sativum
- a genus of annual and perennial herbaceous plants of the 
legume family (Fabaceae), is widely used as a food and fodder crop.
The purpose of this work is to isolate the carbohydrate complex from the aerial part 
of 
Pisum sativum
, collected in the Jizzakh region during the flowering period, to 
establish the physicochemical properties and monosaccharide composition. 
To do this, air-dry raw materials were crushed and treated with ethanol to remove 
low molecular weight compounds. The alcohol extract revealed the presence of glucose, 
fructose and sucrose. To extract the polysaccharides, the plant residue was successively 
extracted with water, oxalate buffer, and alkali. As a result, water-soluble 
polysaccharides (WSPS) were isolated from the aqueous extract, pectin substances (PS) 
from the oxalate extract, and hemicellulose (HMC) from alkaline extract with yields of 
4.9; 4.65; 3.15% respectively. 
Water-soluble polysaccharides are white amorphous powder, highly soluble in water. 
The monosaccharide composition is represented by galactose, glucose, arabinose, 
rhamnose and uronic acid. The IR spectrum of WSPS contains absorption bands 
characteristic of polysaccharides: ν
max
, 3298, 1746 (С=О), 1590, 1413, 1100, 913, 668 
cm
-1
. 
After the separation of WPPS from the meal with a mixture of equal volumes of 
0.5% solutions of oxalic acid and ammonium oxalate at 70°C, PS was extracted. PS-
amorphous powder of beige color, dissolves well in water, forming a thick solution with 
a relative viscosity of 7.14. Galactose, arabinose, rhamnose, and uronic acid were 
identified in PS hydrolyzate. 
Titrimetric analysis established that the content of free carboxyl groups (K
f
) in HP is 
9.0%; esterified carboxyl groups (K
e
) - 23.90%; the degree of esterification (S
e
) is 
72.6%. Therefore, PS is a highly esterified pectin. 
The IR spectrum has characteristic absorption bands for carboxypolysaccharides: 
ν
max
, 3424, 1740 (С=О), 1627, 1444, 1320 (-ОСН
3
), 914, 825 cm-1. 
After extracting PS with 5% KOH solution, hemicellulose (HMC) was isolated with 
a yield of 3.15%. The monosaccharide composition of HMC is represented by 
galactose, arabinose, xylose, rhamnose and uronic acid. The dominant monosaccharide 
in HMC is xylose, i.e. the main polysaccharide is xylan, which is characteristic of this 
type of biopolymers. 
Thus, the presence of alcohol-soluble sugars, water-soluble polysaccharides, pectin 
substances and hemicelluloses in the aerial part of 
Pisum sativum
has been shown. Their 
monosaccharide composition was established and IR spectra were studied.