241
2 Materials
Quercetin, temozolomide, p-sulfonatocalix [4]arene, and
HP-β-CD can be obtained by any source and must be pure 99 + %.
3 Methods
1. Weigh 0.030 g of QUE and 0.306 g of HP-β-CD accurately,
transfer them in a 50 mL beaker, and suspend with 20 mL of
water.
2. Add small amounts of ammonium hydroxide under continuous
stirring and monitor pH until complete dissolution.
3. Adjust pH to a value between 9 and 10.
4. Freeze the resulting solution at a molar ratio of 1:2 at −80 °C
and freeze-dry to get the lyophilized product. Temozolomide
and p-sulfonatocalix[4]arene can be obtained by any source and
must be pure 99+%.
1. Dissolve 10 mg (1 eq) of p-sulfonatocalix[4]arene in 3 mL
phosphate buffer pH 7.0 (10 mM).
2. Dilute 4 mg (1.5 eq) of TMZ in 300 μL MeOH.
3. Mix the solutions of TMZ and calixarene and magnetically stir
at room temperature for 1 h.
4. Filter the homogenous solution through nylon filter with
0.45 mm pore size.
5. Evaporate MeOH under reduced pressure and lyophilize the
aqueous phase giving the temozolomide-calixarene complex.
At the beginning you obtain a
1
H NMR experiment for the complex. The following steps are used:
1. Lock the sample in D 2 Ο (see Note 1) where the complex is dissolved at a constant temperature (see Note 2) and a higher gas
flow than the normal (i.e., 400 L/h) (see Note 3).
2. Tune and match probe head.
3. Optimize the shim values as well as the receiver gain.
4. Obtain a conventional 1D spectrum using a pulsed field gradient unit capable of producing magnetic field pulse gradients in
the z-direction of 53 G cm
−1
(Fig. 5).
5. Calibrate the 90° (
1
H) pulse.
6. Use a sufficient number of scans to obtain a decent signal/noise
(see Note 4).
3.1 Preparation
of the Complex
3.1.1 Preparation
of the Que-HP-β-CD
Complex
3.1.2 Preparation
of the TMZ-Calixarene
Complex
3.2 NMR
Spectroscopy
3.2.1
1
H NMR Spectrum
2D DOSY NMR: A Valuable Tool to Confirm the Complexation in Drug Delivery Systems
2 Materials
Quercetin, temozolomide, p-sulfonatocalix [4]arene, and
HP-β-CD can be obtained by any source and must be pure 99 + %.
3 Methods
1. Weigh 0.030 g of QUE and 0.306 g of HP-β-CD accurately,
transfer them in a 50 mL beaker, and suspend with 20 mL of
water.
2. Add small amounts of ammonium hydroxide under continuous
stirring and monitor pH until complete dissolution.
3. Adjust pH to a value between 9 and 10.
4. Freeze the resulting solution at a molar ratio of 1:2 at −80 °C
and freeze-dry to get the lyophilized product. Temozolomide
and p-sulfonatocalix[4]arene can be obtained by any source and
must be pure 99+%.
1. Dissolve 10 mg (1 eq) of p-sulfonatocalix[4]arene in 3 mL
phosphate buffer pH 7.0 (10 mM).
2. Dilute 4 mg (1.5 eq) of TMZ in 300 μL MeOH.
3. Mix the solutions of TMZ and calixarene and magnetically stir
at room temperature for 1 h.
4. Filter the homogenous solution through nylon filter with
0.45 mm pore size.
5. Evaporate MeOH under reduced pressure and lyophilize the
aqueous phase giving the temozolomide-calixarene complex.
At the beginning you obtain a
1
H NMR experiment for the complex. The following steps are used:
1. Lock the sample in D 2 Ο (see Note 1) where the complex is dissolved at a constant temperature (see Note 2) and a higher gas
flow than the normal (i.e., 400 L/h) (see Note 3).
2. Tune and match probe head.
3. Optimize the shim values as well as the receiver gain.
4. Obtain a conventional 1D spectrum using a pulsed field gradient unit capable of producing magnetic field pulse gradients in
the z-direction of 53 G cm
−1
(Fig. 5).
5. Calibrate the 90° (
1
H) pulse.
6. Use a sufficient number of scans to obtain a decent signal/noise
(see Note 4).
3.1 Preparation
of the Complex
3.1.1 Preparation
of the Que-HP-β-CD
Complex
3.1.2 Preparation
of the TMZ-Calixarene
Complex
3.2 NMR
Spectroscopy
3.2.1
1
H NMR Spectrum
2D DOSY NMR: A Valuable Tool to Confirm the Complexation in Drug Delivery Systems