• Bulletin of the Korean Chemical Society
• /
• v.20 no.12
• /
• pp.1421-1427
• /
• 1999

4-Hydroxy-4'-methoxyazobenzene and 4-hydroxy-4'-cyanoazobenzene were synthesized from phenol with p-anisidine and p-aminobenzonitrile through a diazotization reaction, respectively. They were reacted with 2-chloroethanol, 2-(2-chloroethoxy)ethanol, or 2-[2-(2-chloroethoxy)ethoxy]ethanol to produce six kinds of new mesogenic alcohols having an azobenzene group that is sensitive to the ultraviolet. Twelve kinds of new photoresponsive monomers with two symmetrical mesogens were prepared by the reaction of the mesogenic alcohols with fumaric acid or maleic acid through a Mitsunobu reaction. The resulting monomers have different length of flexible ethyleneoxy spacer tethered to azobenzene group. The length of the spacer affected their thermal stability, solubility, and phase transition temperature. Structures of the monomers were identified by FT-IR and ¹H-NMR spectra. Their phase transition temperatures and thermal stability were also investigated by a differential scanning calorimetry (DSC) and a thermogravimetric analysis (TGA). From an optical polarizing microscopy, all the prepared monomers except fumarate-1 and maleate-1 were found to show enantiotropic liquid crystallinity with a smectic texture like focal-conic, fan-shaped, and batonnet textures.

• Journal of Environmental Science International
• /
• v.8 no.3
• /
• pp.411-417
• /
• 1999

The interfacial chemical behavior, lattice exchange and dissolution, of $FeS_{(S)}$ as one of the important sulfide minerals was studied. Emphases were made on the surface characterization of hydrous $FeS_{(S)}$, the lattice exchange of Cu(II) and $FeS_{(S)}$, and its effect on the dissolution of $FeS_{(S)}$, and also affect some organic ligands on that of both Cu(II) and $FeS_{(S)}$. Cu(II) which has lower sulfide solubility in water than $FeS_{(S)}$ undergoes the lattice exchange reaction when Cu(II) ion contacts $FeS_{(S)}$ in the aqueous phase. For heavy metals which have higher sulfide solubilities in water than $FeS_{(S)}$, these metal ions were adsorbed on the surface of $FeS_{(S)}$. Such a reaction was interpreted by the solid solution formation theory. Phthalic acid(a weak chelate agent) and EDTA(a strong chelate agent) were used to demonstrate the effect of organic lignads on the lattice exchange reaction between Cu(II) and $FeS_{(S)}$. The $pH_{zpc}$ of $FeS_{(S)}$ is 7 and the effect of ionic strength is not showed. It can be expected that phthalic acid has little effect on the lattice exchange reaction between Cu(II) and $FeS_{(S)}$. whereas EDTA has very decreased the removal of Cu(II) and $FeS_{(S)}$. This study shows that stability of sulfide sediments was predicted by its solubility. The pH control of the alkaline-neutralization process to treat heavy metal in wastewater treatment process did not needed. Thereby, it was regarded as an optimal process which could apply to examine a long term stability of marshland closely in the treatment of heavy metal in wastewater released from a disussed mine.

• Journal of Pharmaceutical Investigation
• /
• v.24 no.2
• /
• pp.85-94
• /
• 1994

Inclusion complexes of ketoconazole (KT) with ${\alpha}-$, ${\beta}-cyclodextrin$ (CD) and dimethyl-${\beta}-cyclodextrin$ $(DM{\beta}CD)$ in a molar ratio of 1:2 were prepared by freeze-drying and solvent evaporation methods. The interactions of KT with ${\alpha}-CD$, ${\beta}-CD$ and $DM{\beta}CD$ in aqueous solution and in solid state were investigated by solubility study, infrared (lR) spectroscopy and differential scanning calorimetry (DSC). The stability constant of $KT-DM{\beta}CD$ inclusion complex (lC) was found to be the largest among three inclusion complexes. Clear differences in IR spectra and DSC curves were observed between inclusion complexes and physical mixtures (PM) of KT-CDs. It was also shown by IR spectra and DSC curves that solvent evaporation method might be. superior to the freeze-drying method in preparing the inclusion complexes of KT-CDs. The dissolution rate of KT was markedly increased by inclusion complex formation with CDs in the buffer solution at pH 4.0 and pH 6.8. The mean dissolution time (MDT,min), which represents the rapidity of dissolution, was in the order of $KT-DM{\beta}CD$ IC (3.20) < $KT-{\beta}-CD$ IC (4.36) < $KT-{\alpha}-CD$ IC (6.99) < $KT-{\alpha}-CD$ PM (17.46)< $KT-{\beta}-CD$ PM (19.36) < $KT-{\beta}-CD$ PM (28.53). The dissolution rates of KT-CD ICsprepared by solvent evaporation method were faster than those of KT-CD ICs prepared by freeze-drying method.

• Food Science of Animal Resources
• /
• v.37 no.1
• /
• pp.52-61
• /
• 2017

The objective of this study was to investigate the effects of different concentrations of WSP (wheat sprout powder) and ISP (isolated soy protein) on the quality of breakfast sausage. Treatments were formulated as follows: Control, T1 (2.0% ISP), T2 (1.5% ISP + 0.5% WSP), T3 (1.0% ISP + 1.0% WSP), T4 (0.5% ISP + 1.5% WSP) and T5 (2.0% WSP). The treatments were analyzed for color, pH, cooking loss, emulsion stability, protein solubility, viscosity, texture properties and sensory evaluation. Lightness and redness were reduced and yellowness was increased as increased level of WSP, due to the dark green color of WSP (p<0.05). The pH values of all samples were affected by WSP which has lower pH (p<0.05). The emulsion stability and cooking loss of treatments were improved with increasing level of WSP (p<0.05). The protein solubility, viscosity and overall texture properties of the sausage indicated significant differences in relation to the level of WSP and ISP (p<0.05). The sensory evaluation indicated that the greatest flavor and overall acceptability in sausage was achieved at WSP 1% combination with ISP 1% (T3) (p<0.05). Therefore, these results indicate that breakfast sausage containing 1% WSP and 1% ISP is the optimal formulation, taking into consideration the overall physico-chemical properties and sensory evaluation.

• Archives of Pharmacal Research
• /
• v.26 no.12
• /
• pp.1002-1008
• /
• 2003

Ferulic acid (3-methoxy, 4-hydroxy cinnamic acid) is a flavoid component possessing antioxidant property. The compound is currently under development as a new drug candidate for the treatment of the dementia. The objective of this preformulation study was to determine the physicochemical properties of ferulic acid. The n-octanol to water partition coefficients of ferulic acid were 0.375 and 0.489 at the pHs of 3 and 10, respectively. Accelerated stability study for ferulic acid indicated that the t 90 value for the drug was estimated to be 459 days at $25^{\circ}C$. Ferulic acid was also found to be unstable under the relative humidity of more than 76%, probably because of the hygroscopic nature of the drug. In order to study compatibility of ferulic acid with typical excipients, potential change in differential scanning calorimetry spectrum was studied in 1: 1 binary mixtures of ferulic acid and typical pharmaceutical excipients (e.g., Aerosil, Avicel, CMC, Eudragit, lactose, PEG, PVP, starch and talc). Avicel, CMC, PVP and starch were found to be incompatible with ferulic acid, indicating the addition of these excipients may complicate the manufacturing of the formulation for the drug. Particle size distribution of ferulic acid powder was in the size range of 10-190 $\mu$m with the mean particle size of 61 $\mu$m. The flowability of ferulic acid was apparently inadequate, indicating the granulation may be necessary for the processing of the drug to solid dosage forms. Two polymorphic forms were obtained by recrystallization from various solvents used in formulation. New polymorphic form of ferulic acid, Form II, was obtained by recrystallization from 1,4-dioxane. The equilibrium solubility for Form I was approximately twice of that for Form II. The dissolution rate of Form II was higher than that of Form I in the early phase (<6 min). Therefore, these physicochemical information has to be taken in the consideration for the formulation of ferulic acid.

• Food Science of Animal Resources
• /
• v.22 no.3
• /
• pp.267-273
• /
• 2002

The functional properties of egg shell membrane hydrolysate by Bacillus licheniformis(EESMH) and NaOH-ethanol(AESMH) as a food material were investigated.. The yield of egg shell membrane hydrolysate was about 15% by Bacillus licheniformis, whereas that was 70% by NaOH-ethanol. Histidine content was higher in EESMH (18.69%) than in AESMH (2.56%). Both EESMH and AESMH showed high protein solubility (>95%). Emulsi-fying activity and stability of EESMH were higher than those of AESMH. foaming capacity and stability of AESMH were 2 times higher than those of EESMH in the pH ranges from 2 to 12. The AESMH had antioxidative activity whereas EESMH had not. Therefore, both AESMH and EESMH can be used for industrial food materials from the results of functional properties.

• Journal of Pharmaceutical Investigation
• /
• v.27 no.1
• /
• pp.29-38
• /
• 1997

Precipitation was formed during the preparation of decoction from a mixture of Scutellariae Radix and Coptidis Rhizoma. Baicalin and berberine were identified in this coprecipitated product (CPP) and these components were the active ingredients of two herbal medicine. We extracted respectively crude baicalin and berberine in Scutellariae Radix and Coptidis Rhizoma and prepared coprecipitate of crude baicalin-berberine. To increase the stability and bioavailability of coprecipitate of crude baicalin-berberine(CBB), which is slightly soluble drug, its inclusion complex was prepared and studied in this experiment. Inclusion complex of CBB with ${\beta}-cyclodextrin(CBB-{\beta}-CD)$ was prepared by freeze drying method and its characteristics were ascertained by means of solubility test, differential thermal analysis(DTA) and scanning electron microscope(SEM). The type of $CBB-{\beta}-CD$ is classified as $A_L-type$ on phase solubility diagram, and the stoichiometric ratio of CBB(baicalin in CBB) : ${\beta}-CD$ complex is 1:1 and formation constant is 151 $M^-1$. The solubility, dissolution, in situ absorption and serum concentration of $CBB-{\beta}-CD$ were significantly increased when compared to CBB. Therefore enhanced bioavailability of CBB by inclusion complexation with ${\beta}-cyclodextrin$ might be useful for dosage form design of active ingredients of two herbal medicine.

• Journal of Hydrogen and New Energy
• /
• v.19 no.1
• /
• pp.49-55
• /
• 2008

The feasibility of ionic liquid as a novel absorbent of $SO_2$ for the separation of $SO_2$ from $SO_2/O_2$ mixture in the thermochemical IS(Iodine-Sulfur) cycle was investigated. 1,3-dimethylimidazolium methylsulfate ([DMIm]$MeSO_4$) had shown twenty five times higher solubility of $SO_2$ than that of $O_2$. The dependence of $SO_2$ solubility by [DMIm]$MeSO_4$ on temperature and $SO_2$ partial pressure was examined, which confirmed the possibility of temperature and pressure swing for the separation process. Through cyclic absorption and desorption with temperature swing the stability of [DMIm]$MeSO_4$ in the separation process was also demonstrated. As a result of the experiments carried out, $SO_2$ separation from $SO_2/O_2$ mixture with ionic liquid([DMIm]$MeSO_4$) can be applied to the thermochemical IS cycle.

• Preventive Nutrition and Food Science
• /
• v.5 no.4
• /
• pp.200-204
• /
• 2000

Protein conjugation of curdlan belonging to $\beta$-1, 3-glucan was carried out to improve it surface functionalities. The glucan was mixed with phosvitin, {TEX}$$\alpha$_{s}${/TEX}-casein, lysozyme or ovalbumin, respectively. The mixture was freeze-dried, and he resulting powder was incubated at 6$0^{\circ}C$ and 79% relative humidity for 12 days in order to generate a controlled Maillard reaction between curdlan and proteins. conjugation with unfolding proteins, i.e., phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein, drastically increased the solubility of the glucan, whereas lysozyme and ovalbmin did not. The solubility in water of curdlan was 3.44% for the phosvitin conjugate and 1.09% for the {TEX}$$\alpha$_{s}${/TEX}-casein conjugate. SDS-slab polyacrylamide gel electrophoresis showed that curdlan was solubilized due to covalent binding with phosvitin. Emulsifying properties of curdlan were substantially improved by the conjugation with phosvitin and {TEX}$$\alpha$_{s}${/TEX}-casein. Emulsion stability of the curdlan-phosvitin conjugate was about 2.9 times greater than that of the curdlan-phosvitin mixture.

• Journal of Ginseng Research
• /
• v.42 no.3
• /
• pp.361-369
• /
• 2018

Ginsenosides, dammarane-type triterpene saponins obtained from ginseng, have been used as a natural medicine for many years in the Orient due to their various pharmacological activities. However, the therapeutic potential of ginsenosides has been largely limited by the low bioavailability of the natural products caused mainly by low aqueous solubility, poor biomembrane permeability, instability in the gastrointestinal tract, and extensive metabolism in the body. To enhance the bioavailability of ginsenosides, diverse micro-/nano-sized delivery systems such as emulsions, polymeric particles, and vesicular systems have been investigated. The delivery systems improved the bioavailability of ginsenosides by enhancing solubility, permeability, and stability of the natural products. This mini-review aims to provide comprehensive information on the micro-/nano-sized delivery systems for increasing the bioavailability of ginsenosides, which may be helpful for designing better delivery systems to maximize the versatile therapeutic potential of ginsenosides.