MINISTRY OF EDUCATION VIETNAM ACADEMY OF
AND TRAINING
SCIENCE AND TECHNOLOGY
GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY

HOANG VAN CHINH

RESEARCHING AND EVALUATING ON THE RESOURCES OF
PLANT CONTAING ESSENTIAL OILS AT BEN EN NATIONAL
PARK, THANH HOA PROVINCE; PROPOSING THE
CONSERVATION MEASURES AND RATIONAL EXPLOITATION

SUMMARY OF PHD DISSERTATION

Major: Botany
Code: 9.42.01.11

Supervisors:

1. Assoc. Prof. Dr. Tran Minh Hoi
2. Dr. Do Ngoc Dai

HANOI – 2019


This dissertation has been carried out at The Graduate University of
Science and Technology - Vietnam Academy of Science and Technology

Supervisors:

Assoc. Prof. Dr. Tran Minh Hoi

Lamiaceae, Lauraceae, Apiaceae, Myrtaceae ....
The more developed societies are, the higher in the demand for
learning and using natural origin compounds. The essential oil plants play
an important role in the groups of resourcing plants. Those are essential
materials for cosmetic, food and pharmaceutical industries.
Ben En National Park is located in northwestern Nhu Thanh district,
about 46 km southwest of Thanh Hoa city, with geographical coordinating
from 19º28 'to 19º39' north latitude; 105º20' to 105º35' East longitude. The
natural area of the park is 16,634 ha, including 16 sub-zones, Song Muc lake
and Da Van mountain area, Song Chang.
Ben En National Park consists of mixing types of hills, mountains,
rivers and lakes. The center of National Park is Song Muc lake with a system
of floating islands covering by forests and many spreading branches
surrounded by mixing mountains and land rocky terrain. The highest
mountain is Dam, with 497 m height. The other mountains are 300-350 m,
with average slope from 250 – 300 m, even above 350 m. This terrain is
quite rugged, with steep slopes, with many limestone mountains containing
caves and forests inside. At Ben En National Park, there are plenty of
precious essential oils species such as Cinnamomum parthenoxylon Meisn.,
C. balansae H. Lecomte, C. loureirii (L.) Presl, Citronella spp., Ardisia
silvestris Pitard, Artemisia annua L., Plectranthus aromaticum Benth....
1


Currently, there are a number of studies on flora in Ben En National
Park, such as studies of Do Ngoc Dai et al (2007), Hoang Van Sam (2008),
Ben En National Park (2013). Regarding essential oil plants, there are only
a few studies on chemical compositions and antibacterial activities in some
species of several authors such as Do Ngoc Dai, Nguyen Anh Dung, Ngo
Xuan Luong ... However, those authors only concerned about some aspects,

development in the future.

2


4. Structure of the dissertation
The dissertation consists of 168 pages, except for Introduction,
Conclusions and recommendations, References, and Appendix parts, the
dissertation includes three main chapters:
Chapter 1. Literature review: 30 pages
Chapter 2. Subjects, contents and study methods: 7 pages
Chapter 3. Results and Discussions: 102 pages
CHAPTER 1
LITERATURE REVIEW
1.1. General information of essential oils
1.1.1. Essential oil plant definition
The essential oil plants are plants containing specialized structures that
are responsible for secreting and accumulating essential oils.
1.1.2. Characteristics and chemical compositions of essential oils
Essential oils are mixtures of organic compounds, have complex
molecular structures, are insoluble in water, volatile and have a
characteristic aroma.
1.1.3. Natural state and distribution of essential oils
- Essential oils are in latent or free state in plant body, it could present
in all parts or concentrated in only one or several parts of plant.
- In general, essential oil plants present in the entire plant kingdom but
they especially present in some families.
1.1.4. Using values, importance of essential oils and materials
containing essential oils
For a long time, people have used essential oils in daily life as well as

cubeba, ... were reported. According to La Dinh Moi and Luu Dam Cu
(2001), about 20 essential oil plant species were recently natural exploited
and planted in more or less 600 known species (only 3% of total known
essential oil plant species). Those species are popular cultivated species such
as Citronella spp., Mentha piperita, Ocimum tenuiflorum, Cinnamomum
camphora, Melaleuca sp., C. loureirii (L.) Presl, Pogostemon cablin
(Blanco) Blanco...
1.2.3. Study on essential oil plant species in Thanh Hoa and at Ben En
National Park
Essential oil plant studies were only scattered in some species, and were
not systematic in this area.
1.3. Study on chemical composition and biological activity of some plant
families in the world and in Vietnam
1.3.1. Study on chemical composition and biological activity of some
plant families in the world
1.3.1.1. Lauraceae
In the world, studies on essential oil of Lauraceae mainly focused on
the perfume, pharmaceutical, cosmetic and antifungal, antibacterial pratical
applications. The studied species often belong to the genera Cinnamomum,
Litsea, Machilus ...
1.3.1.2. Rutaceae
Most of the species in the Rutaceae have essential oils or aromas,
and there are many studies in the world on essential oils of Rutaceae. The
author has summaried main studies until 2018.
4


1.3.1.3. Piperaceae
Currently, there are many studies in the world on the chemical
compositions of essential oils and biological activities of the species in

feralit soil developed on sand and weathered groups on limestone
mountains.
1.4.3. Topographic
This area has different types of hills, mountains, rivers and lakes with
quite rugged terrain.
1.4.4. River
5


There are two main river systems in this ares namely Muc river and
Chang river and Ben En lake with a water capacity of 250 - 400 million m3.
1.4.5. Climate
Ben En has a subtropical climate: cold and dry winter; hot and humid
summer.
1.4.6. Status of forest land at Ben En National Park
The area of forested land in Ben En National Park is 11,738.07 ha,
accounting for 79.66 %.
1.4.7. Social conditions
At Ben En National Park area, there are 1 town, 16 communes, 7 stateowned units; Total population is 41,672 citizens, with complex ethnic
composition.
CHAPTER 2
SUBJECTS, CONTENTS AND METHODS
2.1. Study subjects
Essential oil plant species distributing in Ben En National Park, Thanh
Hoa province.
2.2. Study timing
The project was conducted from March 2014 to September 2018.
2.3. Study contents
- Making a list of essential oil plant species and evaluating the
diversity of essential oil species.

in the Herbarium at Hong Duc University.
Samples collected during the field trips were brought back to the
laboratory for further analysis and processing.
Squeezing: Before pressing on the dried, flat and thick newspaper, all
the leaves are fully stretched, not curled edges, parts of flowers or fruits are
opened or cut out to facilitate analysis, pressing and drying samples.
Sample drying: Samples after pressing are dried immediately.
Specimens were identified by comparative morphological method.
For difficult specimens, expert method was used.
A total of more than 1,000 samples were collected and used for
analysis and scientific identification. The sample is currently stored at the
Herbarium, Faculty of Natural Sciences, Hong Duc University.
The main documents used in scientific identification are:
- Vietnamese herbs (Pham Hoang Ho, 1999 - 2003);
- Handbook to Reference and identification of the families of
Angiospermae Plants in Vietnam (Nguyen Tien Ban, 1997);
- General flora of Indochina (1907);
- Flora of China (1994-2002);
- Set of Vietnamese botanicals (Annonaceae, Verbenaceae,
Myrsinaceae, Lamiaceae, Lauraceae, Zingiberaceae) and some other
specialized materials.
Adjusting the scientific name and developing the list: Adjusting the
scientific name according to the List of Vietnamese plant species and The
plant list website (); Sort the list by R. K.
Brummitt and colleagues (1992).
2.4.4. Methods to assess the diversity of flora
- Diversity of taxa of flora: According to Nguyen Nghia Thin's method
(1997).
7


1.5 mg of dried essential oil by anhydrous Na2SO4 in 1 ml of pure hexane
for chromatographic analysis.
+ Gas chromatography (GC) with FID detector: Made on Agilent
Technologies HP 6890N Plus with FID detector, capillary column HP-5MS
length of 30 m, internal diameter (ID) = 0.25 mm, layer film 0.25mm thin
with carrier gas is hydrogen. The temperature of the sample pump chamber
is 250º C. Detect temperature is 260º C. Program temperature 60º C (2
minutes), increase 4º C/minute to 220º C, stop at this temperature for 10
minutes.
+ Gas chromatography mass spectrometry (GC/MS): It is carried out
on Agilent Technologies HP 6890N/HP 5973 MSD conjugated gas
chromatography system with separation column and chromatographic
operating conditions as mentioned above and with helium as carrier gas.
The qualitative determination of essential oil components was done by the
following methods:
- Based on the values of the Retention Index, determinng with a
sequence of n-alkanes in the same chromatographic condition.
- Based on mass spectra, comparing with mass spectra found in data
banks (NIST 08 and Wiley 9th Version) or comparing with the references.
The percentage of components in essential oils were calculated based on the
area or height of the chromatographic peak (detector FID) without using any
adjustment factors.
2.4.6. Methods of investigation and interview
To assess the current status of management, exploitation and use of
plant resources containing essential oils, conducting surveys and direct
interviews with the managers and people.
2.4.7. Biological activity test methods
9



- Bacteria Gr (+): B. subtillis, S. aureus.
- Mold: A. niger, F. oxysporum
- Yeast: S. cerevisiae, C. albicans.
nd
2 step. Samples with positive activities in 1st step were tested
continuously in 2nd step to calculate the minimum inhibitory concentration
(MIC) according to the method of Vanden Bergher and Vlietlink (1991)
conducted on microtitre plates in 96 hours.
Types of antibiotics tested were: Ampicilin, Tetracycline, Nystatin
10


Samples, with a value of MIC ≤ 50 πg /ml, were considered to be
antimicrobial positive.
2.4.8. Data analysis
Data were analyzed on Microsoft Office Excel 2007 software.
CHAPTER 3: RESULTS AND DISCUSSIONS
3.1. Diversity of essential oil plant resources at Ben En National Park,
Thanh Hoa province
3.1.1. Division diversity
The results showed that there were essential oil 410 species, belonging
to 180 genera and 42 families of 2 divisions namely Magnoliophyta and
Pinophyta (Table 3.1) at Ben En National Park. Further more, one additional
species was recorded for the flora of Vietnam, Ben En Pepper (Piper
minutistigmum C. DC.).
Table 3.1. The distribution of essential oil plants in division of flora of Ben
En National Park
Family
Genus
Species

39
9,51
Mag./Li Ratio
6,17
13,83
9,46
Sum
45
100
180
100
410
100
The results showed that most of taxa concentrated in the
Magnoliophyta with 408 species, accounting for 99.51 % of total species;
178 genera, accounting for 98.89 % and 43 families, accounting for 95.56
% of the total of them; there were only 2 species in Pinophyta, accounting
for 0.49 %; 2 genera, accounting for 1.11 % and 2 families, accounting for
4.44 %. Thus, taxa with essential oils mainly concentrated in Magnoliophyta
with the number of genera and species accounting for over 95%. This is
perfectly reasonable compared to the evolution of plants because the
Magnoliophyta is the dominant of higher vacular plants.
The uneven distribution of taxa was not only shown between divisions
but also among classes in the Magnoliophyta.
The Magnoliopsida had a number of taxa that dominate over 80 % of
the total number of families, genera and species of division; Liliopsida had
6 families (accounting for 13.33 %); 12 genera (accounting for 6.67 %) and
11



* Comparing with Pu Mat National Park
In order to reveal the diversity of essential oil species at Ben En National
Park, the results were compared with essential oil species at Pu Mat National
Park by Nguyen Viet Hung (2017) (Table 3.4).
Table 3.4. Comparison of essential oil plants in Pu Mat National Park
compared to Vietnam's essential oil plants
Ben En
Pu Mat(1)
Ben En/Pu
Division
Number
Ratio
Number Ratio
Mat ratio (%)
of species
(%)
of species (%)
12


Pinophyta
2
0,49
6
1,66
33,33
Magnoliophyta
408
99,51
355

Vietnam(2)

Ben En
Division

Number
of species

Ratio
(%)

Number
of species

Ratio
(%)

Ben
En/Vietnam
ratio
9,52
64,15
0,0048
62,41

Pinophyta
2
0,49
21
3,20

grow and develop.
3.1.5. Diversity in stem forms
Studies on the stem forms of essential oil species in Ben En National
Park, based on "Names of Vietnam forest plants" revealed 5 main stem
forms namely big large woody tree, small woody tree, bush tree, climbing
plant and herbaceous plant (Table 3.6).
Table 3.6. Body forms of essential oil plants at Ben En National Park
TT
Dạng thân
ID
Number of Ratio (%)
species
1
Large woody tree
GOL
83
20,24
(over 16 m high)
2
Small woody tree (6-16 m) GON
98
23,90
3
The bush tree
BUI
65
15,85
4
Climbing plant
GLT



TT Using values
ID
Amount
Ratio (%)
1 Medicinal plants
THU
286
69,76
2 Wood plants
LGO
101
24,63
3 Ornamental plants
CAN
24
5,85
4 Edible plants
ĂNĐ
69
16,83
5 Essential oil plants
CTD
410
100
6 Herbs
CGV
13
3,17

oil species were in danger of extinction. Among them, 01 critically
endangered species (CR) - Cinnamomum parthenoxylon Meisn.; 02
endangered species (EN) - Acorus macrospadiceus (Yam.) F. N. Wei & Y.
K. Li) and Acanthopanax trifoliatus (L.) Voss; 05 vulnerable species (VU)
15


- Canarium tramdenum Dai et Yakovt., Actinodaphne elliptibacca
Kosterm., Cinnamomum balansae H. Lecomte, Michelia balansae Dandy,
Ardisia silvestris Pitard.
3.1.8. Characteristics of essential oil chemical composition identified
plant species at Ben En National Park
In this part, the author presented the characteristics of 19 plant species
which were analyzed in chemical composition of essential oils (including
species name, synonym, description, biology, ecology, distribution, using
values, research sample, drawings and color photos).
3.2. The content and chemical compositions of essential oils of some
plants at Ben En National Park, Thanh Hoa
3.2.1. Oil contents of some essential oil plants in Ben En National
Park, Thanh Hoa province
There were 102 samples collected for extracting essential oils, of
which 83 samples belonged to 40 species were identified oil contents, and
other samples had low contentes of essential oils.
The results showed that the content of essential oils ranged from 0.10
% to 1.22 % of fresh weight; The highest amount of essential oil
concentrated in the leaves of Tetradium trichotorum Lour, accounting for
1.22 % fresh weight, followed by the flowers of Michelia alba DC., reaching
1.20 %, .... The average oil content of 83 samples of 40 species was 0.27%
of fresh weight.
3.2.2. Chemical composition of essential oils of some plant species in

Cinnamomum
glaucescens

Leaf

0.42

43

2

Cinnamomum
verum

Leaf

0.45

49

0.18

54

0.12

44

0.45


3

Litsea
glutinosa
Fruit

4

5

Lindera
racemosa

Phoebe
tavoyana

geraniol
(36.2%),
terpinen-4-ol (19.7%), αpinen (6.0%), sabinen
(6.0%) limonen (5.2%)
linalool(22.0%),
bicyclogermacren
(11.2%),β-bisabolen
(7.7%), caryophyllen oxit
(5.6%)
-caryophyllen (26.4%),
limonen
(12.6%),
germacren D (5.1%), pinen (4.6%)
limonen (16.8%), -pinen

chemical compositions accounted for 85.7 % - 99.4 % of the total oil
contents. Monoterpen and sesquiterpen were main compounds in essential
oils.
Table 3.21. Major components of essential oils in different parts of some
species of Piperaceae at Ben En National Park, Thanh Hoa province
No
1

Species
Piper acre

Number of
Percentage of main
stem Amount
identified essential oil components
parts (%)
compounds
(%)
Leaf
0.20
46
(E)-nerolidol
(22.7%),
sabinen (19.5%), δ-cadinen
(12.4%)
E)-nerolidol
(15.6%),
Stem 0.16
52
sabinen (19.9%), δ-cadinen

Leaf

0.15

57

Stem

0.21

45

Leaf

0.20

40

18

spathoulenol (12.4%), βpinen (11.3%), germacren
D (10.1%), isoterpinolen
(8.9%), α-pinen (8.6%)
β-caryophyllen (14.6%),
bicyclogermacree (12.8%),
germacren D (12.3%), 7hydroxy-2methylisoflavon (11.6%),
bicycloelemen
(8.9%),
apiol (8.4%)
-curcumen

(%)
compounds
components (%)
sabinen (36.9%), 3,6dimethylpiperazin-2,5Atalantia
dion
(7.6%),
β1
Leaf
0.35
43
roxburghiana
caryophyllen (6.1%), γterpinen
(3.7%),
bicycloelemen (3.7%)
Leaf
0.43
41
α-pinen (17.5%), βcaryophyllen (15.5%),
caryophyllen oxit (10.6%)
Maclurodendron Fruit
0.71
37
benzyl benzoat (16.8%),
2
oligophlebia
farnesol (8.3%), βcaryophyllen (6.0%),
limonen (4.7%), αcadinol (4.7%)
Leaf
0.12
70

main compounds in essential oils.
Table 3.34. Major components of essential oils in different parts of some
species of Zingiberaceae at Ben En National Park, Thanh Hoa province
Number of
Percentage of main
stem Amount
No.
Species
identified essential oil components
parts (%)
compounds
(%)
β-pinen
(12.1%),
αgurjunen (10.5%), (Z)-13Alpinia
1
Leaf
0.16
73
docosenamit (9.0%), γglobosa
terpinen (4.8%), farnesol
(4.3%)
β-eudesmol (33.3%), βpinen (22.5%), δ-cadinen
Leaf
0.25
25
(8.9%), α-pinen (5.7%),
camphen (5.3%).
β-pinen
(40.8%),

4-ol (9.6%), -pinen (9.2%)
20


4

5

6

Alpinia
tonkinensis

Amomum
villosum

Zingiber
zerumbet

Leaf

0.21

51

Leaf

0.22

22


β-pinen (33.5%), (E)-βocimen (9.6%), γ-terpinen
(9.2%), α-pinen (8.4%)
-pinen (53.6%), -pinen
(24.5%), sabinen (13.6%)
-pinen (38.8%), sabinen
(19.2%), -pinen (18.5%),
-pinen
(30.8%),
caryophylen
(13.0%),
caryophyllen oxit (12.0%),
-pinen (7.8%)
zerumbon
(51.3%),
caryophyllen oxit (5.7%),
camphor (5.2%)
zerumbon
(51.3%),
camphor (6.7%), humulen
epoxit I (6.4%)

3.3. Anti-mosquito and microbial activities of essential oils of Zingiber
zerumbet (L.) Smith)
3.3.1. Mosquito activities
Anti-mosquito and mosquito larvae activities of essential oils in
rhizomes of Zingiber zerumbet revealed that essential oils could kill Aedes
albopictus adults and Culex quinquefasciatus mosquito larvaes. The average
lethal concentration (LC50) after 24h and 48h were shown in Table 3.36.


Management Board and other units and organizations was not good; The
understanding of essential oils was limited; Many types of essential oil
plants are now declining compared to the past.
3.4.2. Solutions to conserve and rationally exploit essential oil resources
in Ben En National Park
Essential oil plant resources play important roles in forest resources
conservation and exploitation. Therefore, in parallel with conserving plant
resources, it is neccessary to proper develope and effective exploit. Combine
the essential oil plants conservation with the development in bufer zones (ex
situ) are important to create benefits, improve income and living standards
for the community.
Within the scope of PhD study, 3 groups of solutions were initially
proposed to conserve and rationally exploit essential oil plant resources at
Ben En National Park: Raising awareness for the community; Solutions for
management; Technical solutions.

CONCLUSIONS AND RECOMMENDATIONS
1. Conclusions
1. Initial identifying 410 essential oil plant species of 180 genera, 45
families, 02 higher plant divisions Magnoliophyta and Pinophyta at Ben En
National Park. In which, one additional species was recorded for the flora
of Vietnam, Ben En Pepper (Piper minutistigmum C. DC.).
2. Species with essential oils belong to 5 main stem types, of which
the most common are herbaceous plants of 123 species (30%), followed by
small woody tree of 98 species (23.9%) and 83 species of big large woody
22


tree (20.24%), bush tree 65 species (15.85%) and climbing plant 41 species
(10%).

to mold with MIC: 50 μg / mL.
8. Proposing 03 measyres of solutions to conserve and rationally
exploit essential oil resources at Ben En National Park, Thanh Hoa province.
2. Recommendations
Studies on essential oil species at Ben En National Park, Thanh Hoa
province in particular and Vietnam in general are still very defficient
compared to their diversity. Therefore, further research is needed to fully
23