vii
TABLE OF CONTENTS
CHAPTER
1
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEGMENTS
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
xii
LIST OF FIGURES
xiv
LIST OF ABBREVIATIONS
xvi
LIST OF SYMBOLS
xviii
LIST OF APPENDICES
xix
INTRODUCTION
1
1.1 Background
1
1.2 Rationale for extraction using subcritical water
Extraction
4
1.3 Research Objectives
6
viii
2
1.4 Statement of Hypothesis
6
1.5
Scope of the study
7
1.6
Benefit of research
7
1.7
Thesis outlines
7
LITERATURE REVIEWS
9
2.1
Subcritical water
9
2.2
The effect of temperature
13
2.3
Subcritical water extraction
16
2.4
Extraction method of natural products
17
2.5
Method of extraction
17
2.6
Natural calcium carbonate
18
2.7
Silica gel
19
2.8
Activated charcoal
20
2.9
Zingiberaceae family
20
2.10
Alpinia mutica
21
2.11
The distribution of compounds in Alpinia
22
Mutica
2.12
The use of Alpinia mutica
24
2.13
The chemistry of the analytes
25
2.14
Compounds studied
26
2.15
Calotropis procera
28
2.15.2 Some use of Calotropis procera
28
2.15.3 The medicinal use of Calotropis
29
procera
3
EXPERIMENTAL
30
3.1
Introduction
31
3.2
Chemicals and materials
31
3.3
Extraction of the three analytes from the
31
rhizomes of Alpinia mutica
3.4
Subcritical water extraction parts
32
3.5
Single extraction temperature
32
3.6
Effect of extraction temperature, pressure and
time in the extraction of natural products using
SWE-NCC
34
ix
3.7
3.6.1
Effect of extraction temperature
34
3.6.1
Effect of extraction pressure
34
3.6.2
Effect of extraction time
35
Optimization of Extraction Parameters and
35
Practical Considerations
3.8
High performance liquid chromatography
36
Parts
3.9
3.10
3.11
3.12
3.13
4
Method validation
37
3.9.1
Selectivity
37
3.9.2
Linearity
37
Preparation of stock standards and working
Solution
3.10.1 Optimization parameters of HPLC
38
3.10.2 The selection of suitable UV
wavelength detection
3.10.3 The selectivity of optimum Flow
rate
3.10.4 The selection of appropriate elution
38
Standard addition
40
3.11.1 Calibration curve
40
The analysis of subcritical water extraction
40
3.12.1 Sampling procedure
40
3.12.2 HPLC Analysis
41
3.12.3 Limit of detection
42
3.12.4 Limit of quantification
43
3.12.5 Precision
43
Quantitative determination by HPLC
44
PREPARATION AND CHARACTERIZATION OF
NATURAL
CALCIUM
38
39
39
46
CARBONATE
ADSORBENT
4.1
Introduction
46
4.2
Objectives
47
4.3
Methodology
47
4.3.1 The surface of CNCC
47
4.3.1 Scanning Electron Microscope (SEM)
47
x
4.3.1 Fourier Transform Infrared Spectroscop
48
(FTIR)
4.4
Results and discussion
48
4.4.1 BET surface area plot of CNCC
49
4.4.2 Scanning Electron Microscope (SEM)
52
of NCC
4.4.3
Fourier Transform Infrared
54
Spectroscopy (FTIR)
5
4.5
Conclusion
55
4.6
Preparation of the sample
54
EXTRACTION
OF
C.
CONVENTIONAL
procera
USING
METHOD
57
AND
SUBCRITICAL WATER EXTRACTION
5.1
General introduction
57
5.2
Objective of this chapter
58
5.3
Equipments and apparatus
58
5.4
Methodology
58
5.4.1
58
Soxhlet extraction method
5.4.1.1
Test of unsaturated sterols
59
5.4.1.2
Test for alkaloids
60
5.4.1.3
Test for flavonoids
60
5.4.1.4
Test for tannin
61
5.4.1.5
Test for saponin
61
5.4.1.6
Test for anthraquinone
61
glycoside
5.4.2
6
SWE-CNCC of C. procera
62
5.5
Results and discussion
63
5.6
Conclusion
65
EXTRACTION
OF
NATURAL
PRODUCTS
67
FROM RHIZOMES OF A. mutica USING SWE
WITH CNCC
6.1
Introduction
67
xi
6.2
Objective of this chapter
68
6.3
Methodology
68
6.4
Results and discussion (comparison of SWECNCC with two different adsorbents)
6.4.1 SWE coupled with Si
69
69
6.4.1.1
Effect of organic modifier on
SWE-Si extract
6.4.1.2 Effect of extraction pressure
72
73
on SWE-Si extract
6.4.2
SWE coupled with AC column
74
6.4.2.1 Effect of extraction pressure
75
on SWE-AC extract
6.4.3
SWE coupled with CNCC column
77
6.4.3.1 The effect of extraction
77
temperature
6.4.3.2
The effect of organic
80
modifier
6.4.3.3
The effect of extraction
82
pressure
6.4.3.4
6.4.3.5
The effect of extraction time
The effect of extraction
83
83
solvent Flow rate
6.4.4 Chromatographic results of SWECNCC
6.4.5 Method validation of extraction
6.5
7
Conclusion
85
85
95
CONCLUSIONS AND FUTURE WORK
96
7.1
Conclusions
96
7.2
Future work
98
REFERENCES
100
Appendices A-H
111-128
xii
LIST OF TABLES
TABLE NO.
TITLE
PAGE
2.1
Critical points of typical solvents.
12
2.2
Distribution of Compounds in Alpinia Species
22
2.3
Distribution of Compounds in A. mutica rhizomes
23
3.1
Acceptable value for reproducibility [AOAC, 2009]
44
4.1
BET surface area of NCC
50
4.2
Infrared frequency (cm-1) of NCC
55
5.1
Preliminary phytochemical screening of C. procera
63
5.2
Conditions applied for the comparison of subcritical
64
water extraction and Soxhlet.
5.3
Yield at different extraction methods (Soxhlet and SWE-
66
CNCC) using different temperatures and modifiers (ACN,
MeOH and EtOH) of the dried leaves of C. procera
6.1
Effect of SWE-Si extraction temperature in the yield of
69
the components from A. mutica rhizomes.
6.2
Yield at different extraction temperature obtained from
71
(SWE-Si) using 6% acetonitrile, 6% Methanol and 6%
Ethanol from the rhizomes of A. mutica
6.3
Effects of different ratio of modifier on the yield of
72
analytes from A. mutica rhizomes obtained by SWE-Si
6.4
Effect of SWE-Si extraction pressure in the yield of the
73
components from A. mutica.
6.5
Effect of temperature on the recovery efficiencies (%) of
the components from A. mutica rhizomes using SWE-AC
74
xiii
6.6
Effect of SWE-AC extraction pressure in the yield
75
recovery of the components from A. mutica.
6.7
Effect of different extraction temperature on yield
obtained
from
SWE-AC
using
different
76
modifier
(acetonitrile, methanol and Ethanol) from the rhizomes of
A. mutica
6.8
Yield (g) of the rhizomes extract from A. mutica using
78
SWE- CNCC at different extraction temperatures.
6.9
Effect of SWE-CNCC extraction temperature in the yield
79
recovery of the components from A. mutica rhizomes.
6.10
Effect of different ratio of modifier on the % yield of
81
analytes from A. mutica rhizomes.
6.11
Effect of SWE-CNCC extraction pressure in the yield of
82
the components from A .mutica.
6.12
Analytical performance of SWE-CNCC in spiked
85
extraction sample
6.13
calibration curve data for the SWE-CNCC of standards
88
xiv
LIST OF FIGURES
FIGURE NO
2.1
TITLE
PAGE
Typical phase diagram. Pc is critical pressure, Tc is
11
critical temperature, Tp is the triple point and Cp is the
critical point
2.2
The molecular structure of kawain
26
2.3
The molecular structure of flavokawain
27
2.4
The molecular structure of 1,7-diphenyle-5-hydroxy-6-
27
heptene-3-one
3.1
Homemade subcritical water extraction
33
3.2
Schematic diagram of HPLC system
36
4.1
BET surface area of NCC
51
4.2
BJH pore size distribution derived from the adsorption
52
and desorption branch of the isotherm of natural calcium
carbonate (CNCC)
4.3
Scanning electron microscope image of CNCC particle
53
sample. (A) 10 µm, (B) 5µm and (C) 1µm
4.4
IR spectrum of CNCC
54
6.1
Effect of flow rate on the SWE-CNCC from 3.5 g of A.
84
mutica rhizomes.
6.2
6.3
Calibration curve for A. Flavokawain, B. DHH, C.
Kawain
HPLC separation of the SWE-CNCC extract of the
87
89
rhizomes of A. mutica recorded at 254 nm
6.4
HPLC chromatogram of standard solution of kawain at
90
wavelength of 254 nm
6.5
HPLC chromatograms of the extract from the rhizomes of
A. mutica
91
xv
6.6
6.7
HPLC chromatogram obtained from SWE-CNCC and
identified as Flavokawain
A. HPLC chromatograms of the extract from the
91
92
rhizomes of A. mutica
6.8
6.9
B. HPLC chromatogram obtained from SWE-CNCC and
identified as kawain
HPLC separations from the rhizomes of A. mutica by (A)
92
93
SWE-Si, (B) SWE-AC and (C) SWE-CNCC
6.10
HPLC separation of the extract of the rhizomes of A
.mutica. (A) Direct injection of extraction before SWECNCC; (B) cleanup the extract by SWE-CNCC. Peak 1
identify as solvent; 2 kawain; 3, DHH; 4, (unknown
peak); 5, flavokawain; 6, (unknown peak).
94
xvi
LIST OF ABBREVIATIONS
AOAC
-
Association of analytical communities
ASE
-
Accelerated solvent extraction
a.m.u
-
Atomic mass unit
BPR
-
Backpressure regulator
AC
-
Activated Charcoal
CNCC
-
Compacted natural calcium carbonate
CPEA
-
Calotropis procera ethyl acetate
Cp
-
Critical point
AK
-
Alkaloids
DH
-
Diarylheptanoids
DHH
-
1,7-diphenyl-5-hydroxy-6-heptene-3-one
e
-
Dielectric constant
FV
-
Flavonoids
GC
-
Gas chromatography
GC-MS
-
Gas chromatography – mass spectrometer
HPLC
-
High performance liquid chromatography
HPLC-MS
-
High performance Liquid Chromatography Mass
Spectrometer
ISWE
-
Improved subcritical water extraction
IR
-
Infrared
LC
-
Liquid chromatography
LG
-
Lignans
LOD
-
Limit of detection
LOQ
-
Limit of quantification
MAE
-
Microwave assisted extraction
xvii
MPa
-
Megapascal (1MPa = 10.19 atm = 145.03 psi)
NCC
-
Natural calcium carbonate
nm
-
Nanometer
NMR
-
Nuclear magnetic resonance
PAF
-
Plated activating factor
PB
-
Phenylbutanoids
PH
-
Phenolic
PP
-
Phenylpropanoids
ppm
-
Part per million
PSE
-
Pressurized solvent extraction
Pc
-
Critical pressure
R%
-
Recovery percent
RP.HPLC
-
Reverse phase high performance liquid chromatography
RP-LC
-
Reverse phase liquid chromatography
RSD%
-
Relative standard deviation percent
SFE
-
Subcritical fluid extraction
ST
-
Stilbenes
STD
-
Standard deviation
SWE
-
Subcritical water extraction
Tp
-
Triple point
Tc
-
Critical temperature
UV
-
Ultraviolet
ZPC
-
Zero point of charge
xviii
LIST OF SYMBOLS
Cp
-
Critical point
e
-
Dielectric constant
Pc
-
Critical pressure
Tc
-
Critical temperature
Tp
-
Triple point