Page 147 - Book of Abstracts

5 International Scientific Online Conference DOI: https://doi.org/10.15414/2021.9788055224015

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ESTIMATION OF ANTIOXIDANT ACTIVITY OF TRIFOLIUM AMBIGUUM M. BIEB
AND T. RUBENS L.
2
1
Olena Vergun , Oksana Shymanska , Dzhamal Rakhmetov , Ján Brindza ,
1
1
Eva Ivanišová
2
1 M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine,
Kyiv, Ukraine; E-mail.: en_vergun@ukr.net
2 Slovak University of Agriculture in Nitra, Nitra, Slovakia
Trifolium L. genus belongs to Fabaceae Lindl., which is an economically important plant
family. Trolium representatives are known as forage plants worldwide and a source of
isoflavones, protein, and biologically active secondary metabolites, among which phenolic
compounds are the main class.
This research provides results of antioxidant activity and polyphenol content of extracts
of Trifolium ambiguum M. Bieb (Kirovograd region, Alexandria district, Dolynske village) and T.
rubens L. (Khmelnytsky region, Krasyliv district, Slobidka village) from Ukrainian natural flora
during 2019–2020. Inflorescences, leaves, stems, and all above-ground parts of plants were
analyzed. The total content of polyphenols (expressed in gallic acid equivalent (GAE) of dry
weight (DW)), flavonoids (expressed in quercetin equivalent (QE) DW), phenolic acids
(expressed in caffeic acid equivalent (CAE) DW), antioxidant activity by DPPH method
(expressed in Trolox equivalent (TE) DW), and reducing power of extracts (expressed in TE
DW) were determined in ethanol extracts of investigated plant parts.
The total content of phenolic compounds for T. ambiguum and T. rubens was from 18.17
(stems) to 91.80 (all plant) and from 17.39 (stems) to 71.24 (leaves) mg GAE/g DW,
respectively. The total content of phenolic acids for T. ambiguum and T. rubens was from 8.16
(inflorescences) to 21.93 (leaves) and from 2.25 (stems) to 12.94 (leaves) mg GAE/g DW,
respectively. It was determined from 5.45 to 30.89 and from 9.58 to 53.20 mg QE/g DW of total
flavonoid content for T. ambiguum and T. rubens, respectively. In both cases, minimal values are
found in stems and maximum values in leaves. The reducing power of extracts had low values
in the stems and high in the leaves for both species. For T. ambiguum this parameter was 36.46–
58.61 mg TE/g DW and for T. rubens 22.93–155.56 mg TE/g DW. The lowest antioxidant activity
by the DPPH method is found in stems and the highest in inflorescences for both species.
Extracts of T. ambiguum demonstrated antioxidant activity from 2.65 to 8.32 mg TE/g DW and
T. rubens from 2.30to 8.62 mg TE/g DW. A very strong correlation between total flavonoid
content and reducing power (r = 0.845) was found in T. ambiguum extracts. Between the total
content of phenolic acids and flavonoids (r = 0.789), reducing power and antioxidant activity by
the DPPH method (r = 0.782) of this extract determined a strong correlation. A very strong
correlation of T. rubens extracts was found between the total content of phenolic acids and
reducing power (r = 0.985), total phenolic content, and total content of flavonoids (r = 0.973).
Reducing power strong correlated with flavonoid content (r = 0.971), phenolic acid content (r
= 0.915), polyphenol content (r = 0.907). Obtained results showed that T. ambiguum and T.
rubens plants are potent sources of polyphenol compounds with high antioxidant activity that
can be used in pharmacological studies. The study of different organs of two Trifolium species
showed that stems accumulated the least content of polyphenol compounds.
Keywords: Trifolium ambiguum, Trifolium rubens, antioxidant activity, polyphenol compounds.
Acknowledgments
Authors are thankful for the Bilateral Scholarship of the Ministry of Education, Science, Research and
Sport (Slovak Republic), the National Scholarship Program of the Slovak Republic for supporting this
research.

5 International Scientific Conference Agrobiodiversity for Improving the Nutrition, Health, Quality of Life and |146
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Spiritual Human Development
November 3 2021
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