Self-assembling properties of 6-O-and 6′-O-alkylsucrose mixtures having different chain lengths under aqueous conditions

Article abstract of DOI:10.1080/07328303.2013.809094

The self-assembling properties of the 6-O-and 6′-O-alkylsucrose mixtures with different chain lengths including octyl, decyl, dodecyl, and tetradecyl under aqueous conditions were studied and compared with those of the 6-O-and 6′-O-hexadecylsucrose mixtur

Full text of DOI:10.1080/07328303.2013.809094

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Self-Assembling Properties of 6-O- and
6′-O-Alkylsucrose Mixtures Having
Different Chain Lengths Under Aqueous
Conditions
Kouhei Tanaka a , Sachie Ohkawabata a , Kazuya Yamamoto a & Jun-
ichi Kadokawa a b
a Department of Chemistry, Biotechnology, and Chemical
Engineering, Graduate School of Science and Engineering ,
Kagoshima University , Kagoshima , Japan
b Research Center for Environmentally Friendly Materials
Engineering , Muroran Institute of Technology , Muroran , Hokkaido ,
Japan
To cite this article: Kouhei Tanaka , Sachie Ohkawabata , Kazuya Yamamoto & Jun-ichi Kadokawa
(2013) Self-Assembling Properties of 6-O- and 6′-O-Alkylsucrose Mixtures Having Different Chain
Lengths Under Aqueous Conditions, Journal of Carbohydrate Chemistry, 32:4, 259-271, DOI:
10.1080/07328303.2013.809094
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Journal of Carbohydrate Chemistry, 32:259–271, 2013
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C
Copyright Taylor & Francis Group, LLC
ISSN: 0732-8303 print / 1532-2327 online
DOI: 10.1080/07328303.2013.809094
Self-Assembling Properties
of 6-O- and 6ꢀ-O-Alkylsucrose
Mixtures Having Different
Chain Lengths Under
Aqueous Conditions
Kouhei Tanaka,1 Sachie Ohkawabata,1 Kazuya Yamamoto,1
and Jun-ichi Kadokawa1,2
1Department of Chemistry, Biotechnology, and Chemical Engineering, Graduate
School of Science and Engineering, Kagoshima University, Kagoshima, Japan
2Research Center for Environmentally Friendly Materials Engineering, Muroran
Institute of Technology, Muroran, Hokkaido, Japan
The self-assembling properties of the 6-O- and 6ꢀ-O-alkylsucrose mixtures with differ-
ent chain lengths including octyl, decyl, dodecyl, and tetradecyl under aqueous con-
ditions were studied and compared with those of the 6-O- and 6ꢀ-O-hexadecylsucrose
mixture previously reported. The title compounds were synthesized from sucrose in
five steps. The results of scanning and transmission electron microscopes, powder X-
ray diffraction, and dynamic light scattering measurements indicated that the self-
assembling properties of octyl, decyl, and dodecyl derivatives were completely differ-
ent from those of the 6-O- and 6ꢀ-O-hexadecylsucrose mixture. The three derivatives
reported here primarily formed lamellar planes, which further induced the formation
of vesicle-type particles under aqueous conditions, whereas the previous derivatives
primarily formed spherical micelles in water, which further assembled according to
face-centered cubic organization by a drying process from the aqueous dispersion. It
was also found that the 6-O- and 6ꢀ-O-tetradecylsucrose mixture showed concentration-
induced micelle-lamellar transition behavior in an aqueous dispersion. Furthermore,
the mixing of a regioisomer, 6ꢀ-O-hexadecylsucrose, with 6-O-hexadecylsucrose induced
different self-assembling properties from that of 6-O-hexadecylsucrose alone, but this
effect did not appear in the self-assembling of the 6-O- and 6ꢀ-O-octylsucrose mixture.
Keywords Sucrose; Monoalkyl ether; Self-assembly; Micelle; Lamellar
Received April 16, 2013; accepted May 23, 2013.
Address correspondence to Jun-ichi Kadokawa, Department of Chemistry, Biotech-
nology, and Chemical Engineering, Graduate School of Science and Engineer-
ing, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan. E-mail:
kadokawa@eng.kagoshima-u.ac.jp
259

K. Tanaka et al.
260
INTRODUCTION
Amphiphilic molecules, so-called amphiphiles, possess antagonistic hy-
drophilic and hydrophobic moieties in the same molecule. In aqueous media,
such molecules self-assemble or self-organize into diverse aggregate morpholo-
gies, such as spherical micelles, cylindrical micelles, spherical vesicles, planer
bilayers, and tubes, depending on the molecular shape and solution condi-
tions.[1] Because glycolipids, which are natural amphiphiles composed of car-
bohydrates as a hydrophilic part, exhibit important in vivo functions in living
systems,[2] synthetic carbohydrate-based amphiphiles have been extensively
studied to exhibit a large variety of self-assembling morphologies.[1]
In the practical application field, synthetic carbohydrate-based am-
phiphiles have been specifically employed as additives in various food
industries in the form of emulsifiers.[3] One of the most effective food additives,
practically employed, is the sucrose fatty acid ester, which is composed of
a sucrose residue, as a hydrophilic part, and long-alkyl fatty acid moieties,
as a hydrophobic part.[4] The self-assembling properties of sucrose fatty
acid esters change depending on the lengths and types of fatty acid chains
and have been investigated extensively.[5] In comparison, self-assembling
studies of sucrose ether amphiphiles carrying long-alkyl chains attached by
ether linkages to the sucrose residue have been less reported. As one of the
examples, the effect of molecular shape on the liquid crystal properties of
mono-O-(2-hydroxydodecyl)sucroses was reported.[6] In the previous paper,
we reported the following self-assembling process of a mixture of 6-O- and
6ꢀ-O-hexadecylsucroses (C16-mixture) under aqueous conditions.[7] The mix-
ture primarily formed spherical micelles with a diameter of approximately
5–7 nm in water, which hierarchically organized according to a face-centered
cubic (FCC) structure during the drying process from the aqueous disper-
sion to construct nanoparticles with a diameter of approximately 50 nm.
Moreover, several nanoparticles further assembled to form larger aggregates.
In the subsequent investigation, furthermore, we synthesized homogeneous
6-O-hexadecylsucrose and evaluated its self-assembling property under
aqueous conditions.[8] It was found that the self-assembling process of the
pure molecule was completely different from that of its mixture containing
the regioisomer, 6ꢀ-O-hexadecylsucrose (i.e., the C16 mixture), in which the
pure molecule showed a hierarchical self-assembling process based on the
primary formation of lamellar planes, leading to vesicle-type particles. It was
also revealed that another 6-O-alkylsucrose with a different chain length
(i.e., 6-O-octylsucrose) was found to show the same self-assembling process as
that of 6-O-hexadecylsucrose. These results indicated that the self-assembling
properties of monoalkylsucroses are different depending on the subtle change
of their molecular shapes.

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
261
On the basis of the above viewpoints, we synthesized in the present study
a series of 6-O- and 6ꢀ-O-alkylsucrose mixtures having different chain lengths
including octyl, decyl, dodecyl, and tetradecyl (C8 mixture, C10 mixture, C12
mixture, and C14 mixture, respectively) and evaluated their self-assembling
properties under aqueous conditions. They were compared with those of the
C16 mixture reported previously.[7] The first three derivatives showed differ-
ent self-assembling properties from those of the C16 mixture but the same
as that of 6-O-hexadecylsucrose as well as 6-O-octylsucrose. Interestingly, the
C14 mixture exhibited different self-assembling properties depending on the
concentrations of its aqueous dispersions.
RESULTS AND DISCUSSION
The 6-O- and 6ꢀ-O-alkylsucrose mixtures were synthesized from sucrose ac-
cording to the same procedure as that described in our previous report
(Sch. 1).[7] Thus, the common intermediate 3 having a hydroxy group at the
6- or 6ꢀ-position was first prepared by the successive tritylation at the 6- or 6ꢀ-
position of sucrose, benzylation of the other hydroxy groups, and detritylation.
Etherification of 3 with the corresponding alkyl bromides was then performed
in the presence of sodium hydride in DMF at elevated temperatures. Deben-
zylation of the products was conducted by catalytic hydrogenation under the
appropriate conditions to afford the C8 mixture, C10 mixture, C12 mixture,
and C14 mixture, respectively. The structures of the materials were confirmed
1
by H NMR and MALDI-TOF MS measurements. The molar ratios of 6-ether
to 6ꢀ-ether in the products, which were calculated from the integrated ratios of
two H1 signals of the glucose residues, were almost 1:1 or higher, because of
the higher reactivity of the 6-position than the 6ꢀ-position. The ratios are given
in the Experimental section.
Then, the resulting products were subjected to the investigation of their
self-assembly properties under aqueous conditions. In the scanning electron
microscope (SEM) images of the samples on aluminum plates (Fig. 1), which
were prepared by drying dispersions of the products in water (1 × 10−5 mol/L),
particle-like nanoaggregates were seen. The average diameters of the parti-
cles from the C8 mixture, C10 mixture, C12 mixture, and C14 mixture sam-
ples were 169, 104, 173, and 156 nm, respectively (the values of the standard
deviations are shown in Table 1). The values and morphologies were much
different from those of the C16 mixture sample because nanoparticles with an
average diameter of ∼50 nm by hierarchical organization according to the FCC
structure and larger aggregates, which were formed by further assembly of the
nanoparticles probably due to their greater density, were observed in the SEM
image of the C16 mixture sample (Fig. 1(e), Table 1). Moreover, the standard
deviation in the diameters of the C16 mixture was much smaller than that in

O
262

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
263
Figure 1: SEM images of the samples prepared from dispersions of (a) C8 mixture, (b) C10
mixture, (c) C12 mixture, (d) C14 mixture, and (e) C16 mixture in water (1.0 × 10−5 mol/L).
the diameters of the other particles (4.34 and 16–45, respectively). To further
confirm the hierarchical structures of the nanoparticles, transmission electron
microscope (TEM) measurement of the selected samples was performed. Dis-
persions of the C8 mixture and C16 mixture in water (1.0 × 10−5 mol/L) were
placed on carbon film-coated grids. After completing the negative-straining
technique, the TEM samples were prepared by drying the preparative materi-
als. The TEM image of the C8 mixture sample (Fig. 2(a)) exhibited vesicle-type
particles with diameters of approximately 100–150 nm, whereas in the TEM
image of the C16 mixture sample (Fig. 2(b)), some particles with diameters
Table 1: SEM, DLS, and XRD results of sucrose ethers
SEM results
Average diameters (nm) by
Standard
devia-
tion
Average
diameter (nm)
DLS results (1.0 × 10−3
XRD
results
Sample
mol/L)
C8 mixture
169
117
44.8
14.4
106.4
105.9
lamellar
lamellar
6-O-octylsucrosea
(1.0 × 10−5 mol/L)
C10 mixture
C12 mixture
C14 mixture
104
173
156
16.3
26.2
22.3
126.5
102.8
6.8
lamellar
lamellar
lamellar
82.0
(1.0 × 10−2 mol/L)
C16 mixtureb
50
51
4.34
12.8
7.1
micelle
(1.0 × 10−5 mol/L)
6-O-hexadecylsucrosea
99.8
lamellar
(1.0 × 10−5 mol/L)
a Reference 8.
b Reference 7.

K. Tanaka et al.
264
Figure 2: TEM images of the samples prepared from dispersions of (a) C8 mixture and (b)
C16 mixture in water (1.0 × 10−5 mol/L).
smaller than 50 nm were seen, which did not exhibit the vesicle-like morphol-
ogy. The above SEM and TEM results indicated that the self-assembling pro-
cesses of the present derivatives under aqueous conditions were completely
different from those of the C16 mixture under the same conditions.
To confirm the self-assembling processes of these derivatives in the dry-
ing state from aqueous dispersions in even greater detail, the powder X-ray
diffraction (XRD) measurement was conducted. Fig. 3 shows the XRD profiles
of the C8 mixture, C10 mixture, C12 mixture, C14 mixture, and C16 mixture
samples, which were prepared by drying their aqueous dispersions (1.0 × 10−3
mol/L). As reported in our previous paper,[7] the XRD profile of the C16 mixture
exhibited diffraction peaks ascribable to the (111), (200), (311/222), (400), and
(600) Bragg reflections of the FCC structure based on the primary formation
of spherical micelles. In the XRD profiles of the other derivatives, on the other
hand, diffraction peaks due to (001) and (002) Bragg reflections of the lamellar
patterns were observed. From the XRD patterns, it was found that the widths
of each lamellar layer increased with an increase in the alkyl chain lengths and
were calculated to be 3.00 nm for the C8 mixture, 3.37 nm for the C10 mixture,
3.76 nm for the C12 mixture, and 4.02 nm for the C14 mixture. These XRD
results of the present four samples suggested that the lamellar planes prob-
ably with alternating hydrophilic sucrose and hydrophobic alkyl layers were
primary formed, which further constructed the vesicle-type nanoparticles with
the 100–150-nm diameters during the drying process from the aqueous disper-
sions as observed in the SEM and TEM images.
To evaluate the self-assembling properties of the above materials in aque-
ous dispersions, then, the dynamic light scattering (DLS) measurement was
performed (1.0 × 10−3 mol/L) (Fig. 4). In our previous paper, we reported the

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
265
Figure 3: XRD profiles of the samples prepared from dispersions of (a) C8 mixture, (b) C10
mixture, (c) C12 mixture, (d) C14 mixture, and (e) C16 mixture in water (1.0 × 10−3 mol/L).
observation of a monomodal profile with the average diameter of ca. 7 nm cor-
responding to a spherical micelle (Fig. 5(b)) in the DLS profile of the aqueous
dispersion of the C16 mixture as shown in Fig. 4(e).[7] On the other hand, the
DLS results of the aqueous dispersions of the C8 mixture, C10 mixture, and
C12 mixture showed the formation of the larger aggregates with the average
diameters of 106.4, 126.5, and 102.8 nm, respectively (Figs. 4(a–c)), which prob-
ably corresponded to the vesicle-like particles formed from the lamellar planes
(Fig 5(a)). The self-assembling processes of these samples were the same as
those of 6-O-octylsucrose or 6-O-tetradecylsucrose alone.[8] On the other hand,
the DLS profile of the aqueous dispersion of the C14 mixture in the same con-
centration showed the smaller particles with the average diameter of 6.8 nm
(Fig. 4(d)) as similar to that of the C16 mixture. This result suggested that
the C14 mixture formed the spherical micelles in this concentration in water,
but that was not consistent with the self-assembling structure in solid state
as observed in the XRD result, which indicated the formation of the lamellar
planes. Interestingly, the average diameter increased to ∼82 nm when the DLS
measurement of the aqueous dispersion of the C14 mixture was conducted un-
der the higher concentration conditions (1.0 × 10−2 mol/L) (Fig. 4(dꢀ)). It was

K. Tanaka et al.
266
Figure 4: DLS profiles of (a) C8 mixture, (b) C10 mixture, (c) C12 mixture, (d) C14 mixture, and
(e) C16 mixture in water (1.0 × 10−3 mol/L) and (dꢀ) C14 mixture in water (1.0 × 10−2 mol/L).
further confirmed by the DLS measurement that the diameters of the parti-
cles in the aqueous dispersions of the C14 mixture were reversibly changed as
Figs. 4(d) and 4(dꢀ) depending on the concentrations. These results suggested
that the C14 mixture showed the concentration-induced micelle–lamellar tran-
sition behavior in the aqueous dispersion as shown in Fig. 5.[9] Therefore, it
was reasonably explained that the XRD profile of the C14 mixture sample in
solid state prepared by drying the aqueous dispersion exhibited the lamellar
pattern. Furthermore, the comprehensive results of our present and previous
studies suggested that the mixing of the stereoisomer 6ꢀ-O-tetradecylsucrose

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
267
Figure 5: Plausible self-assembling processes of (a) C8 mixture, C10 mixture, C12 mixture,
and C14 mixture (higher concentration) and (b) C14 mixture (lower concentration) and C16
mixture under aqueous conditions.
with 6-O-tetradecylsucrose (i.e., the C16 mixture) induced the different self-
assembling property from that of 6-O-tetradecylsucrose alone, but the mixing
did not affect the self-assembling property of the C8 mixture.[7,8] The reason for
the difference in the self-assembling processes of the aforementioned deriva-
tives is not yet clear, but it is obviously suggested that the subtle difference
of their chemical structures strongly affects their self-assembling properties
under aqueous conditions. More detailed studies using methods based on cal-
culations that consider factors such as critical packing parameters are now
in progress to further investigate the reasons for the difference in their self-
assembling processes.
CONCLUSION
This study investigated the comparison of the characteristic self-assembling
processes in the five 6-O- and 6ꢀ-O-alkyosucroses mixtures (C8 mixture, C10
mixture, C12 mixture, C14 mixture, and C16 mixture) with different chain
lengths under aqueous conditions. The former four derivatives were presently
synthesized from sucrose via the five reaction steps, whereas the latter one has
already been synthesized in our previous study.[7] The self-assembling proper-
ties of the materials under aqueous conditions were evaluated by the SEM,

K. Tanaka et al.
268
TEM, XRD, and DLS measurements. Consequently, the former three materi-
als (C8 mixture, C10 mixture, and C12 mixture) primarily formed the lamellar-
like planes in water, which further constructed the vesicle-type particles (Fig.
5(a)), whereas, as previously reported by us,[7] the C16 mixture formed the
spherical micelles in water, which then assembled according to the FCC orga-
nization during the drying process from the aqueous dispersion to construct
the nanoparticles with a size of approximately 50 nm (Fig. 5(b)). Interestingly,
the C14 mixture showed the concentration-induced micelle–lamellar transi-
tion behavior in the aqueous dispersion as shown in Fig. 5, probably due to the
intermediary nature between the C12 mixture and C16 mixture. Taking the
previous results in addition to the present results into consideration as sum-
marized in Table 1, furthermore, it was also confirmed that the mixing of the
stereoisomer 6ꢀ-O-tetradecylsucrose with 6-O-tetradecylsucrose induced a dif-
ferent self-assembling property from that of 6-O-tetradecylsucrose alone, but
the mixing effect was not observed in the self-assembling property of the C8
mixture.[7,8]
EXPERIMENTAL
General
The common intermediate 3 and C16 mixture were prepared from sucrose
according to the literature procedure reported by us.[7] 1H NMR spectra were
recorded on a JEOL ECX400 spectrometer. MALDI-TOF MS measurements
were carried out by using SHIMADZU Voyager Biospectrometry Workstation
Ver. 5.1 with 2.5-dihydroxybenzoic acid as matrix containing 0.05% trifluo-
roacetic acid under positive ion mode. SEM images were obtained using a Hi-
tachi S-4100H electron microscope. The average particle diameters and stan-
dard deviations were calculated on the basis of 50 objects for each SEM image.
TEM measurements were operated using a Jeol JEM-3010 under 200 kV. XRD
measurements were conducted using a PANalytical X’Pert Pro MPD with Ni-
filtered CuKα radiation (λ = 0.15418 nm). DLS measurement was performed
on a Zetasizer Nano ZS (Malvern Instruments).
Synthesis of 6-O-octyl- and 6-O-octylsucuroses Mixture
(C8 Mixture)
Under argon, to a dispersion of NaH (0.105 g, 4.36 mmol) in DMF (5.8 mL)
was added a solution of 3 (0.556 g, 0.582 mmol) in DMF (11.6 mL) at rt and the
mixture was stirred at that temperature for 30 min. After a solution of tetra-
butylammonium bromide (small amount) in DMF (2.0 mL) and 1-bromooctane
(0.36 mL, 2.04 mmol) were added to the mixture, the etherification was con-
ducted at 80◦C for 20 h. The reaction was stopped by addition of methanol

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
269
to the reaction mixture. After the resulting mixture was concentrated and di-
luted with chloroform, the solution was washed with water, dried over anhy-
drous Na2SO4, filtered, and evaporated. The residue was subjected to column
chromatography on silica gel (eluent; ethyl acetate:hexane = 1:50 (v/v)) to give
1ꢀ,2,3,3ꢀ,4,4,6ꢀ-hepta-O-benzyl-6-O-octyl- and 1ꢀ,2,3,3ꢀ,4,4,6-hepta-O-benzyl-6ꢀ-
O-octylsucroses (4-C8, 0.101 g, 0.0928 mmol) in 15.9% yield. 1H NMR (CDCl3)
δ 0.86 (t, 3H, CH3, J = 4.8 Hz), 1.22–1.25 (m, 10H, -(CH2)5-CH3), 1.54 (m,
2H, -O-CH2-CH2-), 3.20–4.20 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-CH2-CH2-),
4.35–4.95 (m, 14H, CH2-Ph), 5.69, 5.70 (2d, 1H, H-1, J = 5.2 and 3.6 Hz),
7.22–7.34 (m, 35H, aromatics).
To a solution of 4-C8 (0.101 g, 0.0928 mmol) in a mixed solvent of bu-
tanol, methanol, and water (2.14 mL, 10:1:0.25 (v/v/v)) was added 10% pal-
ladium on carbon (0.02 g) and the mixture was stirred at rt for 3.5 h under
hydrogen atmosphere. After the reaction mixture was filtered and the filtrate
was evaporated, the residue was subjected to column chromatography on sil-
ica gel (eluent; chloroform:methanol = 10:1) to give 6-O- and 6ꢀ-O-octylsucroses
1
(C8 mixture, 0.023 g, 0.051 mmol, 6-ether : 6ꢀ-ether = 1:1) in 55.0% yield. H
NMR (CD3OD) δ 0.86 (t, 3H, CH3, J = 4.8 Hz), δ 1.30–1.33 (m, 10H, -(CH2)5-
CH3), 1.59 (m, 2H, -O-CH2-CH2-), 3.21–4.10 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ,
-O-CH2-CH2-), 5.36, 5.39 (2d, 1H, H-1, J = 3.0 and 4.2 Hz). MALDI-TOF MS:
Calcd [C20H38O11]Na+: m/z 477.2312. Found: m/z 477.4204.
Synthesis of 6-O-decyl- and 6-O-decylsucuroses Mixture (C10
Mixture)
In the same way as 4-C8, 4-C10 was prepared by the reaction of 3 with 3.5
equivalents of 1-bromodecane at 80◦C for 20 h in 51.2% yield. 1H NMR (CDCl3)
δ 0.86 (t, 3H, CH3, J = 6.2 Hz), 1.22–1.25 (m, 14H, -(CH2)7-CH3), 1.54 (m,
2H, -O-CH2-CH2-), 3.20–4.20 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-CH2-CH2-),
4.35–4.95 (m, 14H, CH2-Ph), 5.69, 5.70 (2d, 1H, H-1, J = 4.8 and 4.0 Hz),
7.22–7.34 (m, 35H, aromatics).
Then, synthesis of the C10 mixture was carried out in the same way as
1
the C8 mixture from 4-C10 in 4.5% yield (6-ether:6ꢀ-ether = 1:1). H NMR
(CD3OD) δ 0.87 (t, 3H, CH3, J = 6.2 Hz), δ 1.30–1.33 (m, 14H, -(CH2)7-CH3),
1.59 (m, 2H, -O-CH2-CH2-), 3.21–4.10 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-
CH2-CH2-), 5.36, 5.39 (2d, 1H, H-1, J = 3.0 and 4.2 Hz). MALDI-TOF MS:
Calcd [C22H42O11Na]+: m/z 505.2625. Found: m/z 505.3256.
Synthesis of 6-O-dodecyl- and 6-O-dodecylsucuroses Mixture
(C12 Mixture)
In the same way as 4-C8, 4-C12 was prepared by the reaction of 3 with
1
3.5 equivalents of 1-bromododecane at 80◦C for 20 h in 39.4% yield. H NMR

K. Tanaka et al.
270
(CDCl3) δ 0.87 (t, 3H, CH3, J = 6.8 Hz), 1.22–1.25 (m, 18H, -(CH2)9-CH3),
1.54 (m, 2H, -O-CH2-CH2-), 3.20–4.20 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-
CH2-CH2-), 4.35–4.95 (m, 14H, CH2-Ph), 5.69, 5.70 (2d, 1H, H-1, J = 4.8 and
3.6 Hz), 7.22–7.34 (m, 35H, aromatics).
Then, synthesis of the C12 mixture was carried out in the same way as
1
the C8 mixture from 4-C12 in 7.28% yield (6-ether:6ꢀ-ether = 5:2). H NMR
(CD3OD) δ 0.89 (t, 3H, CH3, J = 7.2 Hz), δ 1.30–1.33 (m, 18H, -(CH2)9-CH3),
1.59 (m, 2H, -O-CH2-CH2-), 3.21–4.10 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-
CH2-CH2-), 5.36, 5.39 (2d, 1H, H-1, J = 3.0 and 4.2 Hz). MALDI-TOF MS:
Calcd [C24H46O11Na]+: m/z 533.2938. Found: m/z 533.4521.
Synthesis of 6-O-tetradecyl- and 6-O-tetradecylsucuroses
Mixture (C14 Mixture)
In the same way as 4-C8, 4-C14 was prepared by the reaction of 3 with
1
3.5 equivalents of 1-bromotetradecane at 80◦C for 20 h in 26.5% yield. H
NMR (CDCl3) δ 0.88 (t, 3H, CH3, J = 6.8 Hz), 1.22–1.25 (m, 22H, -(CH2)11-
CH3), 1.54 (m, 2H, -O-CH2-CH2-), 3.20–4.20 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ,
-O-CH2-CH2-), 4.35–4.95 (m, 14H, CH2-Ph), 5.69, 5.70 (2d, 1H, H-1, J = 4.8
and 4.0 Hz), 7.22–7.34 (m, 35H, aromatics).
Then, synthesis of the C14 mixture was carried out in the same way as
1
the C8 mixture from 4-C14 in 6.19% yield (6-ether:6ꢀ-ether = 5:3). H NMR
(CD3OD) δ 0.89 (t, 3H, CH3, J = 7.2 Hz), δ 1.30–1.33 (m, 22H, -(CH2)11-CH3),
1.59 (m, 2H, -O-CH2-CH2-), 3.21–4.10 (m, 15H, H-1ꢀ,2,3,3ꢀ,4,4ꢀ,5,5ꢀ,6,6ꢀ, -O-
CH2-CH2-), 5.36, 5.39 (2d, 1H, H-1, J = 3.0 and 4.2 Hz). MALDI-TOF MS:
Calcd [C26H50O11Na]+: m/z 561.3251. Found: m/z 561.4976.
Preparation of Samples for SEM Measurement
A dispersion of 6-O- and 6ꢀ-O-alkylsucroses mixture (1.0 × 10−5 mol/L) was
placed on an aluminum plate and it was left standing under ambient atmo-
sphere until water was evaporated. Then, the resulting solid sample was sub-
jected to the measurement.
Preparation of Samples for TEM Measurement
A dispersion of 6-O- and 6ꢀ-O-alkylsucroses mixture (1.0 × 10−5 mol/L) was
placed on a carbon film-coated copper grid. The negative-staining technique
was used for TEM sample preparation. Then, the preparative material was
left standing under ambient atmosphere until water was evaporated. Then,
the resulting solid sample was subjected to the measurement.

Self-Assembling Properties of 6-O- and 6ꢀ-O-Alkylsucrose Mixtures
271
Preparation of Samples for XRD Measurement
A dispersion of 6-O- and 6ꢀ-O-alkylsucroses mixture (1.0 × 10−3 mol/L) was
placed on a sample plate and it was left standing under ambient atmosphere
until water was evaporated. Then, the resulting solid sample was subjected to
the measurement.
REFERENCES
1. (a) Shimizu, T. Bottom-up synthesis and structural properties of self-assembled
high-axial-ratio nanostructures. Macromol. Rapid Commun. 2002, 23, 311–331.
(b) Fuhrhop, J.-H.; Wang, T. Bolaamphiphiles. Chem. Rev. 2004, 104, 2901–2937.
(c) Shimizu, T.; Masuda, M.; Minakawa, H. Supramolecular nanotube architectures
based on amphiphilic molecules. Chem. Rev. 2005, 105, 1401–1443.
2. (a) Corti, M.; Cantu`, L.; Brocca, P.; Favero, E.D. Self-assembly in glycolipids. Curr.
Opin. Colloid Interface Sci. 2007, 12, 148–154. (b) Kitamoto, D.; Morita, T.; Fukuoka,
T.; Konishi, M.; Imura, T. Self-assembling properties of glycolipid biosurfactants and
their potential applications. Curr. Opin. Colloid Interface Sci. 2009, 14, 315–328.
3. Kralova, I.; Sjoblom, J. Surfactants used in food industry: a review. J. Dispersion
Sci. Technol. 2009, 30, 1363–1383.
4. (a) Hodate, Y.; Ueno, S.; Yano, J.; Katsuragi, T.; Tezuka, Y.; Tagawa, T.; Yoshimoto,
N.; Sato, K. Ultrasonic velocity measurement of crystallization rates of palm oil in oil-
water emulsions. Colloids Surf. A 1997, 128, 217–224. (b) Awad, T.; Sato, K. Effects
of hydrophobic emulsifier additives on crystallization behavior of palm mid Fraction
in oil-in-water emulsion. J. Am. Oil Chem. Soc. 2001, 78, 837–842. (c) Katsuragi, T.;
Kaneko, N.; Sato, K. Effects of addition of hydrophobic sucrose fatty acid oligoesters on
crystallization rates of n-hexadecane in oil-in-water emulsions. Colloids Surf. B 2001,
20, 229–237. (d) Awad, T.; Sato, K. Acceleration of crystallisation of palm kernel oil in
oil-in-water emulsion by hydrophobic emulsifier additives. Colloids Surf. B 2002, 25,
45–53.
5. (a) Molinier, V.; Kouwer, P.J.J.; Fitremann, J.; Bouchu, A.; Mackenzie, G.; Que-
neau, Y.; Goodby, J.W. Self-organizing properties of monsubstituted sucrose fatty acid
esters: The effects of chain length and unsaturation. Chem. Eur. J. 2006, 12, 3547–3557.
(b) Goodby, J.W.; Go¨rtz, V.; Cowling, S.J.; Mackenzie, G.; Martin, P.; Plusquellec, D.;
Benvegnu, T.; Boullanger, P.; Lafont, D.; Queneau, Y.; Chambert, S.; Fitremann, J. Ther-
motropic liquid crystalline glycolipids. Chem. Soc. Rev. 2007, 36, 1971–2032.
6. (a) Gagnaire, J.; Cornet, A.; Bouchu, A.; Descotes, G.; Queneau, Y. Study of
the competition between homogeneous and interfacial reactions during the synthe-
sis of surfactant sucrose hydroxyalkyl ethers in water. Colloids Surf. A 2000, 172,
125–138. (b) Queneau, Y.; Gagnaire, J.; West, J.J.; Mackenzie, G.; Goodby, J.W.
The effect of molecular shape on the liquid crystal properties of the mono-O-(2-
hydroxydodecyl)sucroses. J. Mater. Chem. 2001, 11, 2839–2844.
7. Kanemaru, M.; Kuwahara, S.; Yamamoto, K.; Kadokawa, J. Self-assembly of 6-O-
and 6ꢀ-O-hexadecylsucroses mixture under aqueous conditions. Carbohydr. Res. 2010,
345, 2718–1722.
8. Ohkawabata, S.; Kanemaru, M.; Kuwahara, S.; Yamamoto, K.; Kadokawa, J. Syn-
thesis of 6-O-hecadecyl- and 6-O-octylsucroses and their self-assembling properties un-
der aqueous conditions. J. Carbohydr. Chem. 2012, 31, 659–672.
9. (a) Takahashi, Y.; Kondo, Y.; Schmidt, J.; Talmon, Y. Self-assembly of a
fluorocarbon-hydrocarbon hybrid surfactant: dependence of morphology on surfactant
concentration and time. J. Phys. Chem. B. 2010, 114, 13319. (b) Gummel, J.; Sztucki,
M.; Narayanan, T.; Gradzielski, M. Concentration dependent pathways in spontaneous
self-assembly of unilamellar vesicles. Soft Matter. 2011, 7, 5731.