Organizing co mmittee

4
with the yield 56 % and 44 %, 
respectively. We should note that the treatment of compound 
3 
with the
 
40% solution of 
KOH/EtOH at room temperature or under reflux do not lead to the formation of 
compound 
4
. 
It was also found that the reaction proceeded according to the mechanism of second-
order nucleophilic substitution with inversion of the configuration in compounds
 3
and 
4
. The structure of all synthesized compounds is confirmed by NMR spectroscopy data. 
References 
1. W. Dehaen, A.A. Mashentseva, T.S. Seitembetov // Molecules. 
2011
. V. 16. №3. 
P. 2443–2466.
2. L.M. Zakirova, I.P. Baikova, I.E. Smirnova, E.V. Тretyakova, A.N. Lobov, H.T.T. 
Nguyen, O.B.
 
Каzakova 24-Nor-allobetulins possess strong α-glucosidase inhibitory 
activity // Nat. Prod. Res
.
2022. 
DOI: 10.1080/14786419.2022.2154347 

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Poster presentation 
54 
ANTIOXIDANT ACTIVITY OF PINUS SYLVESTRIS AND PINUS 
SIBIRICA NEEDLES EXTRACTS 
 
V.V. Kraynik 
Surgut State University, [e-mail] 
Introduction. 
Pinus is a popular medicinal plant that is used in several traditional 
medicines to cure various diseases. Shoots, buds, bark, roots and wood contain various 
active components with anti-inflammatory, expectorant, multivitamin and analgesic 
properties. 
Research methods. 
The study material consisted of 
Pinus sylvestris
and 
Pinus 
sibirica
needles collected in 2022 from the city park (Russia, Khanty-Mansi 
Autonomous Okrug – Ugra, Surgut). The needles were collected in May (spring) and in 
October (autumn) and fixed using natural-air drying at 25 °C for 72h. The dried needles 
were crushed to a particle size of 0.5 - 0.9 mm. 
The total content of favonoids (TCF) was estimated using a method based on the 
formation of favonoids with aluminium (III) ions. The result was expressed as the rutin 
equivalent. 
The volume of extract in ml used for titration with 1 ml of 0.05N potassium 
permanganate solution served as an indicator of relative antioxidant activity (AOA). 
The result was expressed as the quercetin equivalent.