Authors:Edward Onyango, Elikplimi Asem, and Olayiwola Adeola
Thompson, L. U. (1986): Phytic acid: A factor influencing starch digestibility and blood glucose response. In: Graf, E. (ed.) Phytic Acid: Chemistry and Applications. Pilatus Press, Minneapolis, MN. pp. 173
Authors:X. Cao, X. Yang, J. Shi, Y. Liu, and C. Wang
The effect of glucose (0–15 mass%) on the kinetics of bovine serum albumin (BSA) denatured aggregation at high concentration
in aqueous solution has been studied by differential scanning calorimetry. The observed denatured aggregation process was
irreversible and could be characterized by a denaturation temperature (Tm), apparent activation energy (Ea), the approximate order of reaction, and pre-exponential factor (A). As the glucose concentration increased from 0 to 15 mass%, Tm increased, Ea also increased from 514.59409±6.61489 to 548.48611±7.81302 kJ mol−1, and A/s−1 increased from 1.24239E79 to 5.59975E83. The stabilization increased with an increasing concentration of glucose, which was
attributed to its ability to alter protein denatured aggregation kinetics.
The kinetic analysis was carried out using a composite procedure involving the iso-conversional method and the master plots
method. The iso-conversional method indicated that denatured aggregation of BSA in the presence and absence of glucose should
conform to single reaction model. The master plots method suggested that the simple order reaction model best describe the
process. This study shows the combination of iso-conversional method and the master plots method can be used to quantitatively
model the denatured aggregation mechanism of the BSA in the presence and absence of glucose.
The physical ageing characteristics of glucose, fructose, and their mixtures were studied using standard differential scanning calorimetry (DSC). The inflection, onset, midpoint,half-height, and endpoint glass transition temperature (Tg), fictive temperature (Tf), and relaxation enthalpy (
H) were measured as a function of ageing time. The relationship between
H and Tf was evaluated. The time dependence of
H was fit using the Cowie and Ferguson model. The ageing rate was expressed in terms of the average relaxation time (<>) and the entropy production (P). It was found that the fructose component decreased the rate of ageing of the mixtures.
Triprolidine hydrochloride (C19H22N2·HCl·H2O) (TPH) is a well-known antihistamine drug which is reported as being photosensitive. The thermal stabilities of TPH and
of 1:1 molar and 1:1 mass ratio physical mixtures of TPH with β-cyclodextrin (BCD) and with glucose have been examined using
DSC, TG and TG-FTIR, complemented by X-ray powder diffraction (XRD) and infrared spectroscopic (IR) studies. Thermal studies
of the solid TPH/BCD mixtures indicated that interaction between the components occurs and it is possible that the TPH molecule
may be least partially accommodated in the cavity of the BCD host molecule. XRD results support this indication of inclusion.
The results of molecular modelling suggest that TPH is most likely to be accommodated in the BCD cavity as a neutral triprolidine
molecule with the toluene portion of the molecule preferentially included in the cavity. The results obtained illustrate the
general stability of TPH. The study has also shown TPH to be compatible with both glucose and BCD, which are potential excipients
both in solid and liquid dosage forms. The presence of these excipients in dosage forms will thus not adversely affect the
stability and the therapeutic efficacy of TPH.
Triprolidine hydrochloride, C19H22N2HClH2O (TPH) is a well-known antihistamine drug, which is reported as being photosensitive. Solid-state photostability studies
of TPH were undertaken by irradiating TPH and its binary mixtures with β-cyclodextrin (BCD) and glucose, using an Atlas Suntest
CPS+ irradiation chamber and conditions according to the guidelines of the International Committee on Harmonization (ICH). HPLC
analysis was used to determine the extent of photodegradation. XRD results showed that changes in the TPH crystal structure
had occurred during irradiation and that these changes increased with the time of irradiation. Although the potential for
isomerization under the influence of UV-light to the pharmaceutically inactive Z-isomer exists, results have proved that this
transformation for solid-state TPH would require more extreme light conditions. The results of this study thus illustrate
the general light stability of TPH in the solid-state.
Authors:M. Cicchi, C. O'sullivan, B. Fried, and J. Sherma
Seven different thin-layer chromatography stationary phases, one additional stationary layer pretreatment, eight mobile phases, two spotting techniques, and three detection reagents were evaluated for the determination of glucose in mouse fecal samples. Quantitative analysis was performed by slit-scanning densitometry. The optimal system was found to be Merck silica gel HPTLC plates with a concentrating zone developed with 1-butanol-glacial acetic acid-diethyl ether-deionized water 27:18:5:3. α-Naphthol-sulphuric acid detection reagent was found to give the best quantitative results, while the naphthoresorcinol reagent was the most useful for qualitative analysis. Semiautomatic application of samples with a CAMAG Linomat was found to give more compact bands and better separations than manual application. Using this system, quantification of glucose was achieved in mouse fecal samples. The amounts of glucose in the fecal samples of BALB/c mice infected with the intestinal trematode E. caproni were compared to control samples of uninfected mice. On the third and tenth days of postinfection, it was determined that the amount of glucose in the infected fecal samples was significantly greater than in the control samples. This indicates that metabolic profiling of glucose using TLC is possible in the mouse model and that TLC may potentially be used to test for the presence of E. caproni in humans.
Authors:Teréz Márián, L. Balkay, I. Fekete, Zs. Lengyel, and G. Veress
Shawver, L. K., Olson, S. A., White, M. K., Weber, M. J. (1987) Degradation and biosynthesis of the glucose transporter protein in chicken embryo fibroblasts transformed by the src oncogene. Mol. Cell Biol. 7
Authors:Magda Alania, Varya Dyakonova, and D. A. Sakharov
Ruibal, C., Soengas, J. L., Aldegunde, M. (2002) Brain serotonin and the control of food intake in rainbow trout ( Oncorhynchus mykiss ): effects of changes in plasma glucose levels. J. Comp. Physiol. 188A , 479