Page 89 - Zbornik_Konf_2019

https://doi.org/10.15414/2019.9788055220703

4 International Scientific Conference Abstracts Book
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PRELIMINARY PHYTOCHEMICAL SCREENING OF ORCHID PLANTS GROWN
EX SITU AND IN VITRO

2
1
1
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Roman Ivannikov , Iryna Laguta , Lyudmila Buyun , Oksana Stavinskaya ,
1
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Viktor Anishchenko , Olena Boyko
1 M.M. Gryshko National Botanic Garden, National Academy of Sciences of Ukraine, Kyiv, Ukraine;
E-mail.: ivannikov@nbg.kiev.ua
2 Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
Screening of the living plant collections, maintained in Botanic Gardens, aimed at
identifying the potential sources of biologically active compounds is an extremely promising
area for various research projects. Using the bank of sterile plant tissue cultures of the
Laboratory of plant biotechnology and tropical plant collections of M.M. Gryshko National
Botanic Garden (NBG), the phytochemical screening of the extracts of 20 orchid species from
Dendrobium Sw. genus has been undertaken. High-performance liquid chromatography and
laser desorption/ionization mass spectrometry were used to analyze the composition of the
leaves extracts derived from the plants grown under different conditions (both ex situ and іn
vitro). Phenolic (hydroxycinnamic and hydroxybenzoic) acids and flavonoids in glycoside
form were found to be the main groups of bioactive compounds of the extracts. Flavonoids, in
their turn, were presented mainly by flavonols and flavones, with quercetin, kaempferol,
rhamnetin, apigenin and luteolin being the most abundant aglycons. The extracts also
contained the anthracene and phenanthrene derivatives, alkaloids, coumarins,
furanocoumarins, terpenoids; the extract of Dendrobium chrysanthum Wall. ex Lindl. (grown
ex situ) were found to include also catechins.
The antioxidant properties of the extracts in the reaction with DPPH stable free radical
were assessed. Four extracts from the plants grown ex situ and one extract from the plant
grown in vitro were found to exhibit high antiradical activity, inhibiting half or more of free
DPPH radicals. The comparison of the extract from the plant grown ex situ and in vitro
revealed that in most cases the first ones had higher antioxidant properties.
To develop dosage forms for prolonged antioxidants release, two types of composite
materials were prepared using the extracts as an active ingredient and fumed silica or silica-
gelatin matrix as auxiliary components. Adsorption/precipitation of the extracts on fumed
silica surface was found to lead to the prolonged release of only part of bioactive compounds
of a particular structure, while the inclusion of the extracts in silica-gelatin matrix allows
achieving significant and non-specific deceleration of the desorption of all the extracts
components. Thus, the silica-gelatin matrixes with embedded orchid extracts seem to be
promising dosage forms for prolonged antioxidants release: the components of the extracts
are effective natural antioxidants while silica-gelatine matrix provides their gradual release
and prolonged action.
Keywords: plant extracts, Orchidaceae Juss., antioxidants, flavonoids.

Acknowledgments
The work was supported by the Targeted Comprehensive Interdisciplinary Research Program of NAS
of Ukraine 'Molecular and cellular biotechnology for medicine, industry and agriculture'. The
investigations were accomplished on the basis of the sterile plant tissue cultures collection of tropical
and subtropical plants Department of NBG. Since 1999 the whole collection of tropical and subtropical
plants (including orchids), maintained both ex situ and in vitro, has the status of a National Heritage
Collection of Ukraine and is supported through State funding.

4 International Scientific Conference Agrobiodiversity Nutrition, Health and Quality of Human and Bees Life |89
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September 11–13, 2019