Biology Reference
In-Depth Information
1
H NMR measurements. The XRD profiles of the product from
POXT showed the same pattern as that from PTHF. Furthermore, the
1
and
showed the signals due
to both amylose and POXT. These observations indicated that the
inclusion complex was formed by using POXT as the guest polyether.
However, the XRD pattern of the product obtained with PEG was
similar to that of amylose. In addition, the peak due to PEG was not
observed in the
H NMR spectrum of the product in DMSO-
d
6
H NMR spectrum of the product. No formation of
the inclusion complex with PEG was detected from these analytical
data. This was probably attributed to the hydrophilicity of PEG,
which caused less hydrophobic interaction between PEG and the
cavity of amylose. These results indicated that the hydrophobicity of
the guest polymers was an important factor for the formation of the
inclusion complexes in this type of polymerization system.
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7.4
Preparation of Amylose-Polyester Inclusion
Complexes
Since the importance of the hydrophobicity of the guest polymers was
found, hydrophobic polyesters as guest polymers such as telechelic
poly(
ε
δ
-valerolactone)s
(PVLs) were employed for the preparation of amylose-polyester
inclusion complexes [29,30]. The phosphorylase-catalyzed
enzymatic polymerization of Glc-1-P from Glc
-caprolactone)s (PCLs) and telechelic poly(
was performed in
the presence of the polyesters in the sodium citrate buffer (Fig.
7.2c,d). The resulting products were characterized by means of
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1
H
NMR and XRD measurements, which supported the structures of the
inclusion complexes. When PCL with higher molecular weight (
M
n
= 2000) was used as the guest polymer for the experiment same as
the aforementioned, the PCL was not dispersed well in the citrate
buffer, and accordingly, the inclusion complex was not formed. To be
dispersed in the reaction solvent, the polymerization was conducted
in a mixed solvent of citrate buffer with acetone (5:1, v/v). The
obtained product was characterized by means of the
1
H NMR and XRD
measurements to be the inclusion complex. The inclusion complex
was formed in citrate buffer by using PVL with a molecular weight of
2000, indicating that the PVLs had more advantageous properties as
guest polymers for the formation of the inclusion complexes in the
citrate buffer compared with the PCLs.
