The 7th International Conference on Engineering and Technology
ICET-2015, Phuket, June 19-20, 2015
Prince of Songkla University, Faculty of Engineering
Hat Yai, Songkhla, Thailand 90112
Effect of Ethanol on Inclusion Complexation
of α-mangostin and β-cyclodextrin
Pichthida Jittamaro1*, Apinan Soottitantawat1,
Uracha Rangsardthong Ruktanonchai2, Sarunya Phunpee2
1
Chulalongkorn University, Faculty of Engineering, Thailand
National Nanotechnology Center (NANOTEC), National Science and Technology
Development Agency 111 Thailand Science Park, Pathumtani THAILAND
*
Email of corresponding author: Pichthida.J@student.chula.ac.th
2
Abstract: The effect of ethanol on inclusion
complexation is determined by calculation the variable
with result of HPLC. The result shows the soluble αmangostin concentration will increase while ethanol is
high but from the calculation shows that the ethanol
concentration will decrease the binary complexation
with ρb is 5.64 M-1 and will increase ternary
complexation with ρt is 0.17 M-1. α-Mangostin can be
form to the ternary complexation upon high ethanol
concentration.
Key Words: α-Mangostin / β-Cyclodextrin
/ Inclustion complexation
1. INTRODUCTION
α-Mangostin (C24H26O6) is substance that is extracted
from xanthone found in pericarp, whole fruit, bark and
leaves of Garcinia mangostana Linn. Many researchs
show its benefits of antioxidant, antitumoral, antiinflammatory, antiallergy, antibacterial, antifungal and
antiviral activities. It can be applied to pharmaceutical
and cosmetically industries. But it is solid state at room
temperature and poorly water soluble (0.0094 gL-1). Its
molecular weight is 410.46 gmol-1. In order to get more
efficiency, we require α-mangostin to be continuously
released for a long time by encapsulation and control
release technology.
Cyclodextrin is widely used in encapsulation and
control release technology. It is cyclicoligosaccharide of
α-D-Glucose by moltodextrin glucanotransferase.
The formation of inclusion complex between guest
molecules and CDs can be formed. However, since αmangostin is in solid form, the inclusion complex cannot
occur in physical method. Thus, solvent is needed to
form the inclusion complex.1
The inclusion is complex between host and guest.
The host molecule is residence of the guest molecule.
The binary inclusion has only one species of guest
molecule. The ternary inclusion has 2 species of guest
molecule.2
2. MATERIALS AND METHODS
2.1. Materials
α-Mangostin (α-mg) with an average molecular
weight (Mw) of 410.46 gmol-1 with purchased from
GuanzhouHonsea Sunshine Bio Science& Technology
Co., Ltd in China. β-cyclodextrin (βCD) was obtained
from Wacker Chemical AG (Germany). Methanol,
ethanol, n-propanol, i-propanol, butanol were purchased
from carlo Erba (Italy). Dimethyl sulfoxide (DMSO),
n,n-diamethylformamide (DMF), 1,4 dioxane were
purchased from Sigma Aldrich (USA). Water used for all
experiments was purified water obtained from a milliQ
Plus (Millipore, Schwalbach, Germany).
2.2. Binary inclusion of α-mg with β-CD
β-CD (5.0 g) was dissolved in DI water (100 mL).
The solution of β-CD was heated up to 70°c and stirred
at 200 rpm. Add α-mg 41.0 mg (20 mmol) in 12-ml vials.
The β-CD solution were varied from 0-10 mmol in each
vial. Then, the vials were sonicated for 15 minutes. After
that they were shaken at 25°c 250 rpm for 48 hours.
2.3. Ternary inclusion of α-mg, ethanol with β-CD
β-CD (5.0 g) was dissolved in DI water (100 mL).
The solution of β-CD was heated up to 70°c and stirred
at 200 rpm. Add α-mg 2.46 g in 150 ml of ethanol. The
βCD solution were varied from 0-10 mmol in each vial.
The α-mg solution 2 ml (20 mmol of α-mg, 40%MeOH)
was added to vials. Then, the vials were sonicated for 15
minutes. After that they were shaken at 25°c 250 rpm for
24, 48 and 72 hours. The concentration of ethanol was
varied from 0.3-60%.
2.4. Characterization
The total concentration of α-mg was measured by
HPLC. The C18 column (thermo scientific) (2.1x250
mm, 5 μm) is used in this research. Mobile phase is 1%
(v/v) acetic acid and methanol in ratio 1:9. Flow rate is 1
ml/min. The sample rate is 10 μL. The analysis time is
12 minutes.
3. METHODS
In this study, the mixture were filtered by 0.45 μm
nylon filter membrane to separate insoluble α-mg from
the solution. The concentration of inclusion was
determined by Ping model.3,4
The result of HPLC shows the total concentration of
α-mg that dissolves in solution [Dtot] as show Eq.1
(1)
Dtot  D  DL  DLC .

     

Where [Dtot] is , [D] is the free α-mg that is dissolve
in solvent is but it is not inclusion with β-CD, [DL] is the
binary complexation that is α-mg with β-CD, [DLC] is
the ternary complexation that is α-mg and ethanol with
β-CD. However we cannot find each term from HPLC
but we use the equation to relate the result and calculate
the constant variable for solving term of binary and
ternary inclusion.
3.1. Determination of the α-mg concentration in
water or ethanol solutions
The solubility of nonpolar solutes on solvent
concentration that is described exponential form as eq 2,
which can be written in log-linear forn as eq 3.
D  Du  10 C .
log D  log Du    C .
(2)
Where [DLC] is ternary complexation of α-mg,
ethanol and β-CD. Ktapp is apparent
ternary
complexation constant. Ktapp is a function with solvent
concentration and the intrinsic complexation constant,
Kbint as eq 7.
K tapp  K tint  10  t C 
(7)
Where ρt is the destabilitizing power of the ethatnol
for the ternary complex.
where D is free α-mg that is soluble α-mg but it is
not inclusion with β-CD. DL is soluble α-mg in binary
inclusion and DLC is soluble α-mg in ternary inclusion.
Plot graph from the result of HPLC to calculate
the constant variable to solve term of binary and ternary
inclusion.
3. RESULTS AND DISCUSSION
3.1. Solubilization by Ethanol
The intrinsic solubility [Du] of α-mg was determined
to be 1.946e-3 mM Figure 1 shows relationship between
quantity of soluble α-mg [D] and ethanol concentration
[C]. The graph is described by eq 2. The sovlent
solubilizing power (σ) is 0.3038 M-1.
Fig. 1 shows the concentration of soluble α-mg
increases upon etanol concentration.
(3)
Where [D] is the total soluble α-mg concentration,
[Du] is the intrinsic α-mg solubility, [C] is ethanol
concentration, σ is the ethanol solubilizing power for
the solute. Equation 3 shows that the logarithm of α-mg
solubility increases linearly with ethanol concentration.
3.2. Determination of the concentration α-mg
with β-CD in binary inclusion term [DL]
The concentration of binary complex [DL] between
nonpolar solutes and ligand is described in eq 4.
DL   K bapp [ D][ L]
(4)
Where [DL] is the total α-mg complexation with βCD that is related to the concentration of free α-mg [D]
and the β-CD concentration [L]. However it has the
apparent binary complexation constant, Kbapp.
Kbapp is a function with solvent concentration and the
intrinsic complexation constant, Kbint as eq 5.
K bapp  K bint  10  b C 
(5)
Fig. 1. Effect of ethanol concentration
solubility.
on the α-mg
3.2. Solubilization by β-CD
The concentration of soluble α-mg increases linearly
with β-CD concentration. The Kbint was determined to be
2.79e-3 M-1 and ρb is 5.64 M-1 from eq 4 and 5. Fig. 2
shows the binary complexation of α-mg with β-CD.
Where ρb is the destabilitizing power of the ethatnol
for the α-mg complexation with β-CD. Equation 4 and 5
show that the [DL] is linearly form with ethanol
concentration.
3.2. Determination of the concentration α-mg and
ethanol with β-CD in ternary inclusion term [DLC]
The concentration of the ternary complex that has
relationship with solute, ligand and solvent (ratio 1:1:1)
is related to the free solute concentration , the ligand
concentration and the solvent concentration as eq 6.
DLC   K tapp DLC 
(6)
Fig. 2. Effect of β-CD concentration on the soluble α-mg
concentration.
3.3. Solubilization by β-CD and Ethanol
The concentration of soluble α-mg increases linearly
with ethanol concentration. The Ktint was determined to
be 2.17e-3 M-1 and ρt is 0.17 M-1 from eq 6 and 7. Fig. 3
shows the ternary complexation of α-mg and ethanol
with β-CD.
.
Fig. 3. Effect of Ethanol concentration on the
complexation of α-mg , ethanol and β-CD.
4. CONCLUSION
α-mg solubility in the result is the sum of free α-mg,
α-mg in binary complexation with β-CD and α-mg in
ternary complexation. Ethanol concentration will give
rise to an exponential decrease in binary because the
magnitude of σ is smaller than ρb from eq 4 and
5.However, ethanol concentration will increase the
ternary complexation because the magnitude of σ is
greater than ρt from eq 6 and 7.
5. REFERENCES
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Fluasterone
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