We determined the phenolic and total flavonoid contents and some physiological characteristics (water potential, chlorophyll fluorescence, chlorophyll index) of Paeonia lactiflora Pall., growing in the Botanical Garden, Mongolian Academy of Sciences. Cultivated plants were harvested at the beginning of vegetation (May), flowering (June), seed formation (July), seed dispersal (August) and end of vegetation season (September).

1. 47
© 2017 Journal compilation
http://mjbs.num.edu.mn
http://biotaxa.org./mjbs
Volume 15(1-2), 2017
Mongolian Journal of Biological
Sciences
ISSN 1684-3908 (print edition)
ISSN 2225-4994 (online edition)
MJBS
Original Ar cle
http://dx.doi.org/10.22353/mjbs.2017.15.06
Seasonal Variation of Some Bioactive Compounds and
Physiological Characteristics in Peony
(Paeonia lactiflora Pall.)
Shagjjav Oyungerel1
, Gachmaa Batzaya2
, Gurbazar Byamba-Yondon2
,
Bayasgalankhuu Lyankhua1
, Naidansuren Ochgerel2
, Dalaikhuu Usukhjargal2
1
Department of Biology, National University of Mongolia, Ulaanbaatar, 14201, Mongolia
2
Institute of General and Experimental Biology, Mongolian Academy of Sciences, Ulaanbaatar 13330,
Mongolia
Abstract
We determined the phenolic and total flavonoid contents and some physiological
characteristics (water potential, chlorophyll fluorescence, chlorophyll index) of
Paeonia lactiflora Pall., growing in the Botanical Garden, Mongolian Academy of
Sciences. Cultivated plants were harvested at the beginning of vegetation (May),
flowering (June), seed formation (July), seed dispersal (August) and end of vegetation
season (September). Phenolic content in leaf and stem was increased during the
vegetation period and the highest level was reached during the seed formation stage,
and it decreased at the end of the vegetation stage. On the contrary, the total flavonoid
content in leaf and stem is decreased linearly as the development stages advanced and
the highest level was observed at the flowering stage. Variations of water potential,
chlorophyll fluorescence and chlorophyll index of cultivated P. lactiflora, increase at
the beginning of vegetation and flowering stages, and decrease from seed formation
stage to end of the vegetation stage.
Oyungerel, Sh., Batzaya, G., Byamba-Yondon, G., Lyankhua B., Ochgerel, N.,
Usukhjargal, D. 2017. Seasonal variation of some bioactive compounds and
physiological characteristics in peony (Paeonia lactiflora Pall.). Mong. J. Biol. Sci.,
15(1-2): 47-51.
Introduction
Key words: Paeonia
lactiflora, physiological
characteristics, phenolic,
flavonoid
Article information:
Received: 24 March 2017
Accepted: 24 Oct. 2017
Published online:
01 Nov. 2017
Correspondence:
oyungerel@num.edu.mn
Cite this paper as:
There are 116 tribes, 674 categories and 3014
species of vascular plants, of which 53 endangered
species and 81 species of rare plants in Mongolia
(Red Book of Mongolia, 2013). Among them
1,000 species of plants, which considered as
essential ingredients in medicine (Ligaa, 2015).
Paeonia lactiflora is a herbaceous perennial
of the family Ranunculaceae, and widely
distributed in Russia, Mongolia, Korea, Japan
and China. In Mongolia, it occurs in Mongol
Daguur and Khyangan regions (Grubov, 1986).
This plant is recorded in the List of Very Rare
Plants of Mongolia and it is also included in the
Mongolian Red Data Book, with very rare status.
Paeonia lactiflora was known as the white
peony (P. albiflora) when it first introduced into
Europe. It has been brought to England in the
mid of 18th century, and is the parent of most
modern varieties. There are many colors now
available from pure milk white to pink, rose, and
near red along with single to fully double forms.
They are prolific bloomers, and have become the
main source of peonies for the cut flower business
(Josef et al., 2004).
The genus Paeonia has received considerable
interest from scientists, as it contains the root

2. Oyungerel et al. Bioactive compounds and physiological characteristics of Paeonia lactiflora48
and aboveground parts of traditional medicine
products. In China, Korea, Japan and Mongolia,
a decoction of the dried root without bark of P.
lactiflora, is used in the treatment of rheumatoid
arthritis, hepatitis, systemic lupus erythematosus,
dysmenorrhea, muscle cramping and spasms
(Dong & Sheng, 2011; Ligaa, 2015).
There are two kinds of research works in P.
lactiflora. The first one is about the influencing
factors to number and diameters of flowers.
Secondly, since it is an essentially important
medicinal plant, the focus of the other research
works concentered on the biologically active
compounds.
Therefore, it is critical to develop rehabilitation
methodologies, adapt the sustainable use, and
conserve the plant resources, through immediate
measures including monitoring the affected
or endangered species, conducting biological
and eco-physiological researches, and studying
concentrations of biologically active compounds.
In the present study, were investigated some
bioactive secondary metabolites and physiological
characteristicsofP.lactifloraduringthevegetation
period.
Material and Methods
Plant material. We used P. lactiflora planted
in the Botanical Garden of the Mongolian
Academy of Sciences, in Ulaanbaatar for our
study. The stem leaves and shoots of P. lactiflora
were used as experimental materials. The plant
vegetation period was determined as follows:
beginning of vegetation (May), flowering (June),
seed formation (July), seed dispersal (August)
and end of vegetation season (September) (Fig.
1). The phytochemical samples were dried at
room temperature and then crushed in a grinder.
Its powder was stored in polythene bags until
subjected to analysis. For the analysis of phenolic
and flavonoid contents, the dried plant materials
were extracted with 80% aqueous methanol for
48 hours, afterwards filtered and appropriately
diluted with 80% methanol.
Determination of total flavonoid content.
The plant extracts were prepared according to
the standard protocol. The content of flavonoids
in the examined plant extracts was determined
using aluminum chloride colorimetric assay. The
sample contained 0.2 ml of the plant extract with
a concentration 0.2 ml of 5% AICI3
solution was
dissolvedinwater.Thesamplewasincubatedfor30
minutes at the room temperature. The absorbance
was determined using spectrophotometer at
430 nm. The total flavonoid content of extracts
was expressed as the percentage of Quercetin
equivalent per 100 g of a dry sample (Cos et al.,
1998).
Determination of total phenolic content.
The total phenolic content was determined by
spectrophotometer, using Gallic acid as the
standard and method described by Singleton
and Rossi (1965). The total phenolic content
was expressed as Gallic acid equivalents in
mg/100ml of stems and leaves. The concentration
of polyphenols in samples was derived from a
standard curve of Gallic acid ranging from 100 to
500 µg/ml.
Determination of the water potential. The
water status of the plant was assessed through
measuring the water potential of shoots on rainless
days with clear skies, using a Model 1515D
Pressure Chamber Instrument and applying the
methodof Scholander etal.(1964).Wedetermined
the water potential when the turgor was equal to
zero in cultivated P. lactiflora.
Determinationofthechlorophyllfluorescence
indices. Fluor Pen (FP 100) measured the
chlorophyll fluorescence indices. The quantum
yield (QY) of photosynthesis was defined as
the molar ratio between oxygen released in
photosynthesis to photons absorbed in the
process. The maximum value of optimal quantum
yield (QY) is 0.832 in C3
plants (Schreiber &
Bilger, 1993). The chlorophyll fluorescence
Beginning of vegetation Flowering Seed formation End of vegetation
Figure 1. Seasonal variation of P. lactiflora

3. 49Mongolian Journal of Biological Sciences 2017 Vol. 15 (1-2)
decrease ratio Rfd correlates with the potential
CO2
fixation rate of leaves. When Rfd ≥ 2.5 the
normal photosynthetic activity is indicated and on
the other hand, at Rfd < 1 the low photosynthetic
activity was confirmed (El-Sharkawy, 2006). The
chlorophyll fluorescence indices were measured
during the vegetation period of P. lactiflora.
where, P is maximum chlorophyll fluores-
cence yield measured when the actinic radiation
is switched on; -steady stats chlorophyll fluores-
cence yield in the light-adapted stae.
Ft is instantaneous chlorophyll fluorescence
Ft is equivalent to Fo if the leaf sample is dark-
adapted state,
Fo is minimum chlorophyll fluorescence in
dark-adapted state,
QY is Quantum Yield is a measure of the
Photosystem II efficiency. In a dark-adapted leaf,
this is equivalent to Fv/Fm. In a light-adapted leaf
it is equivalent to Fv’/Fm’.
Fv=Fm-Fo, maximal variable fluorescence,
Fm is maximum chlorophyll fluorescence in
dark-adapted state, measured during the first satu-
ration flash after dark adaptation,
Rfd is chlorophyll fluorescence decrease ratio,
defined as ratio Fd/Fs, when measured at satura-
tion irradiance, correlates with the potential CO2
fixation rate net photosynthetic (PN) of leaves as
shown for several plants as well as sun and shade
leaves.
Fd is chlorophyll fluorescence decrease from
P to Fs,
Fs is steady state chlorophyll fluorescence.
Determination of the chlorophyll index. The
SPAD 502 Chlorophyll Meter instantly measured
chlorophyll content (index) or “greenness” of
our plants. The SPAD 502 Plus quantifies subtle
changes or trends in plant health, long before
they become visible to human eyes. Non-invasive
measurement simply clamps the meter over leafy
tissue and receives an indexed chlorophyll content
reading (-9.9 to 199.9) in less than 2 seconds.
Results
Seasonal variation of total flavonoid and
simple phenolic. Phenolic compounds are
the particularly important source of natural
antioxidants. They comprise two main groups;
both flavonoid and phenolic acids are present in
herbs. Flavonoid is capable of reducing the risk of
cancer and protecting biological systems through
inducing detoxification enzymes, habiting
cancer. Some flavonoids are found effective in
treating heart diseases by inhibiting blood platelet
aggregation, providing antioxidant protection for
a low-density lipoprotein cell proliferation and
promoting cell differentiation.
The total flavonoid and simple phenolic
compounds were determined in the leaf and stem
of P. lactiflora during the vegetation period. The
total flavonoid content was increased from May
to June, but it was decreased in July, August and
September. The total flavonoid contents were
significantly higher (P < 0.01) in leaves than
stems. Actually, it was about 7 times higher in the
leaf than in its stem in June (Fig. 2). Choudhary
and Swarnkar (2011) also showed the higher
total flavonoid content in leaves as compared to
that in the stem of the some medicinal plants. As
shown in Figure 3, simple phenolic content was
significantly increased from May to June, whereas
it is decreased from August to September in the
leaves and stems.
The total flavonoid content was increased
in May and June in the leaf and stem, and then
decreased in July and August. A simple phenolic
content was increased in May and July, and was
found as decreased in August and September.
In summary, the best time to use P. lactiflora
as medicinal plants and raw materials, is during
flowering and seed formation periods.
Figure 2. Seasonal variation of total flavonoid content
in leaves and stems of P. lactiflora.
Asterisks indicate significant differences between the
total flavonoid (P = 0.01).

4. Oyungerel et al. Bioactive compounds and physiological characteristics of Paeonia lactiflora50
Seasonal variation of physiological char-
acteristics. The increased water potential was
found at the beginning of vegetation and flower-
ing stages (-0.27±0.11 and -0.24±0.14), and the
decreased water potential was observed from
the seed formation to the end of vegetation sea-
son (-0.57±0.22 and -0.70±0.21). In order to as-
sess water deficit of P. lactiflora, water potential
value of each month where the turgor was equal
to zero compared to an average water potential
of the typical month. The seasonal variation of
the water potential in the P. lactiflora was higher
compared to the seasonal variation at zero turgor
from May to August (Fig. 4). Our result indicated
that the cultivated P. lactiflora never experiences
water deficit, and grows well under conditions
with abundant water sources.
The use of chlorophyll fluorescence to monitor
photosynthetic performance in plants has become
a widespread method. We determined the daily
chlorophyll fluorescence (Ft), optimal quantum
yield (QY) and ratio fluorescence decrease (Rfd)
of P. lactiflora with two hours of intervals per
each month.
Indices of optimal quantum yield (QY) and ratio
fluorescence decrease (Rfd) were found relatively
low in May, but increased in June and July, then
decreased again fromAugust to September (Fig. 5).
In addition, color changes especially in leaves
are important criteria for visual evaluation of the
development of plant stresses. The chlorophyll
index of P. lactiflora was the lowest (31.0±3.46) in
May, increased from June and the highest
(54.5±7.2) in July, then decreased (44±3.03) from
August and became a relatively low (36.3±5.54) in
September (Fig. 6). Seasonal variation of the
chlorophyll index, optimal quantum yield and
ratio fluorescence decrease of P. lactiflora have
direct correlations.
Traits of the plant related to its productivity
and water potential, photosynthesis, chlorophyll
fluorescence and chlorophyll index were identified
Figure 3. Seasonal variation of a simple phenolic
content in leaves and stems of P. lactiflora.
Asterisks indicate significant differences between total
flavonoid (P = 0.01).
Figure 4. Seasonal variation of water potential and
points of zero turgor in P. lactiflora.
Asterisks indicated the significant differences between
the water potential and zero turgor (P = 0.01).
Figure 5. Seasonal variation of QY and Rfd in
P. lactiflora.
Figure 6. Seasonal variation of chlorophyll index in
P. lactiflora.

5. 51Mongolian Journal of Biological Sciences 2017 Vol. 15 (1-2)
and selected as parental materials in traditional
medicine. Furthermore, the research has revealed
relevant information on the physiological
mechanisms underlying productivity of P.
lactiflora and its tolerance to prolonged droughts,
which shall aid in improving the crop management
in both favorable and stressful environments.
Our research results showed that the
effectiveness of physiological processes in P.
lactiflora was high in June and July, and it was
lessened in May and September. Moreover, it has
indicated that the cultivated P. lactiflora grows
well in an environment with sufficient water
sources.
Acknowledgement
This work supported by the Asia Research
Center at the National University of Mongolia,
and the Korean Foundation for Advanced Studies,
Korea.
References
Bailey, G. S. & Williams, D. E. 1993. Potential
mechanisms for food related carcinogens and
anti-carcinogens. Food Technology, 47: 105–
118.
Choudhary, R. K. & Swarnkar, P. L. 2011.
Antioxidant activity of phenolic and flavonoid
compounds in some medicinal plants of India.
Natural Product Research, 25(11): 1101–1109.
Cos, P., Ying, L., Calomme, M., Hu, J. P., Van,
P. B., Pietrers, L., Vlietinck, A. J. & Berghe,
D. V. 1998. Structure-activity relationship and
classification of flavonoids as inhibitors of
xanthine oxidase and superoxidase scavengers.
Journal of Natural Products, 61: 71–76.
Dong, Y. H. & Sheng, M. D. 2011. “Anti-
inflammatory and immunomodulatory effects
ofPaeonialactifloraPall.,atraditionalChinese
herbal medicine”. Frontiers in Pharmacology,
pp.1–5.
El-Sharkawy, M.A. 2006. Utility of basic research
in plant/crop physiology in relation to crop
improvement: a review and a personal account.
Brazilian Journal of Plant Physiology, 18:
419–446.
Grubov, V.I. 1986. Key to the Vascular Plants of
Mongolia. Michurin Printing, Moscow, 107
pp.
Lee, B. W., Lee J. H., Lee, S. T., Lee, H. S.,
Lee, W. S., Jeong, T. S. & Park, K. H.
2005. Antioxidant and cytotoxic activities
of xanthones from Cudrania tricuspidata.
Bioorganic and Medicinal Chemistry Letters,
15: 5548–5552.
Ligaa, U. 2015. “Medicinal plants of Mongolia
used in western and eastern medicine”.
IMUNAL Co Ltd., Ulaanbaatar, pp. 480–481.
Pietta, P. G. 2000. Flavonoids as antioxidants.
Journal of Natural Products, 63: 1035–1042.
Scholander, P. F., Hammel, H. T., Hemmingsen,
E. A. & Bradstreet, E. D. 1964. Hydrostatic
pressure and osmotic potential in leaves of
mangroves and some other plants. Proceedings
of the National Academy of Sciences USA, 52:
119–125.
Singleton, V. L. & Rossi, J. A. 1965. Colourimetry
of total phenolics with phosphomolybdic-
phosphotungstic acid reagents. American
Journal of Enology and Viticulture, 16: 144–158.
Schreiber, U. & Bilger, W. 1993. Progress in
chlorophyll fluorescence research: major
developments during the past years in
restrospect. Progress in Botany, 54: 151–173.
Ueda, H, Yamazaki, C. & Yamazaki, M. 2002.
Luteolinasananti-inflammatoryandanti-allergic
constituent of Perilla frutescens. Biological
Pharmaceutical Bulletin, 25: 1197–1202.
*****