• Bulletin of the Korean Chemical Society
• /
• v.23 no.9
• /
• pp.1315-1327
• /
• 2002

The model compounds, 8-methoxypsoralen-CH2O(CH2)n-adenine (MOPCH2OCnAd, n=2, 3, 5, 6, 8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N9 of adenine. UV absorption spectra are identical with the sum of MOPCH2OC3 and adenine absorption spectra. Solvent effects on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the $(\pi${\rightarrow}$\pi*)$ state. The spectral characteristics of the fluorescence of MOPCH2OCnAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structureless due to the excimer formation through the folded conformation accelerated by hydrophobic ${\pi}-{\pi}$ stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, and consequently to an increase in the fluorescence intensity, fluorescence lifetime, and a shift of fluorescence maximum to longer wavelengths. The decay characteristics of the fluorescence in polar protic solvents shows two exponential decays with the lifetimes of 0.6-0.8 and 1.6-1.9 ns in 5% ethanol/water, while MOPCH2OC3 shows 0.5 and 1.7 ns fluorescence lifetimes. The long-lived component of fluorescence can be attributed to the relaxed species (i.e., the species for which the solvent reorientation (or relaxation) has occurred), while the short-lived components can be associated with the unrelaxed, or only partially relaxed, species.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.759-760
• /
• 2000

5-fluorouracil loaded chitosan-cellulose microspheres was prepared by W/O/W multiple emulsions solvent evaporation technique which is appropriate to oral drug delivery. The influences of process parameters on the physical characteristics of microspheres and on in vitro drug release were investigated.

• YAKHAK HOEJI
• /
• v.44 no.6
• /
• pp.511-520
• /
• 2000

Various bupivacaine-loaded microspheres were prepared from poly (d,l-lactide) (PLA) or poly (d,l-lactic-co-glycolide) (PLGA) by a solvent evaporation method for the sustained release of drug. PLA and PLGA microspheres were prepared by w/o/w and w/o/o multiple emulsion solvent evaporation, respectively. The effects of process conditions such as emulsification speed, emulsifier type, emulsifier concentration and internal/external phase ratio on the characteristics of microspheres were investigated. The prepared microspheres were characterized for their drug loading, size distribution, surface morphology and release kinetics. Drug loading efficiency was higher in the microspheres prepared by w/o/o multiple emulsion than that by w/o/w multiple emulsion method, because the solubility of bupivacaine HCI was decreased in oil phase compared with water phase. The prepared microspheres had an average diameter between 1 and $2\;{\mu}M$ in all conditions of two methods. In morphology studies the PLA microspheres showed an irregular shape and smooth surface, but PLGA microspheres had a spherical shape and smooth surface. The release pattern of the drug from microspheres was evaluated on the basis of the burst effect and the extent of the release after 24h. The in vitro release of bupivacaine HCl from microspheres showed a large initial burst release and $60{\sim}80%$ release within one day in all conditions of two methods. The extents of the burst release against PLA and PLGA microspheres were $30{\sim}50%$ and $50{\sim}80%$ within 20min, respectively. This burst release seems to be due to the smaller size of microspheres and the solubility of drug in water.

• Journal of Pharmaceutical Investigation
• /
• v.13 no.2
• /
• pp.73-87
• /
• 1983

The matrix affects the dissolution of furosemide, which is almost insoluble in the dissolution medium. In order to understand the effect of the matrix on the dissolution of furosemide, lactose, starch, $Avicel\;^{\circledR}pH\;101$, $Avicel\;^{\circledR}pH\;301$, $SiO_2$ and talc were used as the matrix and the solvent deposition method were used. The dissolution characteristics of four dissolution medium were compared to each other using various ratio of drug-to-matrix. The results are as follows: 1) Lactose was shown to be superior and talc was to be inferior to the other matrixes investigated. 2) A maximum dissolution rate and dissolution amount of furosemide were observed in 1 : 10 ratio of the drug-to-matrix. 3) $T_{80%}$ of 1 : 10 ratio of the drug-to-matrix in pH 7.2 was 1 min. from FM-lactose and 30 min. from FM-talc. $T_{50%}$ in pH 4.2 is 2 min. from furosemide-lactose and 150 min. from furosemide-talc. Total amount of furosemide in pH 1.2 at 30 min. were enhanced 13.3 fold in furosemide-lactose and 3.5 fold in furosemide-talc compared to the control. Diuretic action of those furosemide-lactose and furosemide-talc was also evaluated by monitoring changes in urinary excretion of sodium, potassium and urine volume in rat. The accumulated urine volume were enhanced 1.7 fold in furosemide-lactose (1.5) compared to the furosemide.

• Journal of Conservation Science
• /
• v.34 no.6
• /
• pp.569-580
• /
• 2018

The possibility of applying poulticing was studied for removing Paraloid B72, a resin used for fixing an earthen mural painting. Five types of poultices were selected from clay and gel types, and acetone, ethanol, and methyl ethyl ketone(MEK) were used as mixed solvents. The possibility of mixing between the poultice and solvent was investigated, and then the spreadability, fluidity, acidity, drying properties, and solubility of the poultices were examined to confirm the characteristics. A poultice agent, which is suitable for applying to a mural painting, was selected and applied to a painting layer sample coated with Paraloid B72. As a result, all painting layers were good condition at under 50% of the solvent. The removal efficiency of Paraloid B72 was more effective when most of the solvents were used at 50%, rather than at 25%. However, it is difficult to mix 50% of MEK and ethanol with the gel-type poultices. When used at 25%, the removal performance was poorer than that at 50%, but the mixing with all the poultices was successful. In addition, the adsorption and removal power of the gel-type poultice were better than those of the clay-type, but the latter was expected to be more suitable in short-time cases due to its high drying speed. The results of this study show that the dissolution performance varies depending on the poultices and solvents. Hence, the poultice and solvent should be selectively applied, considering the fixative of the mural to be removed.

• Fashion & Textile Research Journal
• /
• v.16 no.3
• /
• pp.476-484
• /
• 2014

The purpose of this study was to investigate the dyeing properties and anti-microbial ability of silk and wool fabrics dyed with Terminalia chebula Retzius(TCR) extract using two extraction solvent, hot water and methanol. Dyeing properties of fabrics were studied by investigating the characteristics of colorant, changes in dye uptake under different dyeing conditions, and by investigating color change when mordants were applied. Also, color fastness, and antimicrobial activity of dyed fabrics were estimated. Regardless of extraction solvent type, colorant showed maximum absorption wavelength at 280 nm and 578 nm, which implied that tannin was the major pigment component of TCR. Also, through FT-IR spectrum result, it was confirmed that tannin of TCR methanol extract was hydrolysable tannin. But for the hot water extract, it was only assumed that its tannin was condenced tannin. Fabric dyed with hot water solvent extract showed higher dye uptake than fabric dyed with methanol solvent extract, dye uptake increasing by higher concentration of the dye, longer dyeing time and higher dyeing temperature. And the absorption curve between TCR extract and protein fiber was shaped in the form of Langmuir adsorption isotherm. Fabric dyed without mordant was yellow in color, and when dyed with mordant, fabric showed various colors depending on mordant types except Sn. Color fastness to washing was generally fine and color fastness to light was moderate. But color fastness to rubbing and dry cleaning was outstanding. Lastly, dyed fabrics showed very good antimicrobial activity of 99.9% against Staphylococcus aureus and Kiebsiella pneumoniae.

• Korean Journal of Food Science and Technology
• /
• v.17 no.4
• /
• pp.276-282
• /
• 1985

To characterize bitter peptides in fermented protein foods, peptides were extracted with 2:1 (v/v) chloroform-methand from various samples and separated into fractions I, II, and III by Sephadex G-25 gel chromatography. Amino acid compositions of Mozzarella cheese, soybean paste, and each fraction from the two samples were analyzed to calculate the average hydrophobicity. All the solvent extracts of the food samples had strong bitter taste, although the original samples did not taste bitter. The yield of solvent extraction ranged from 0.08 to 62.50% of total nigrogen of food samples. The average hydrophobicity calculated from the amino acid composition of Mozzarella cheese was 1376 cal/mole, solvent extract 1,623 cal/mole, gel chromatography traction I, 1,797 cal/mole, fraction II, 2,454 cal/mole, and fraction III, 1,559 cal/mole. In the case of soybean paste, the average hydrophobicity of original sample, solvent extract, gel chromatography fraction I, II, and III wre 1,229, 1,654, 1,900,998 cal/mole, respectively. The important amino acids in bitter peptides were leucine, 2016, phenylalanine, proline, and voline.

• Journal of Ginseng Research
• /
• v.37 no.4
• /
• pp.468-474
• /
• 2013

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and $65^{\circ}C$ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at $200^{\circ}C$ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that ${\beta}$-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.

• Korean Journal of Food Science and Technology
• /
• v.21 no.6
• /
• pp.851-856
• /
• 1989

The physical properties of essential oil of nutmeg extracted in different methods (SDE, Solvent, $CO_2$) were investigated and also the components of essential oil were analyzed using G.C. and G.C./ Mass. Solvent extraction yield was 23% and was higher than those of SDE extraction and $CO_2$ extraction. From the analysis result and physical properties of nutmeg oil, it was conformed that the nutmeg used In this experiment was similar to East Indies type. The content of sabinene was 3.6-14.1%, 28.4-48.7% for myristicin, 1.2-2.1% for elemicin, and 3.6-5.6% for safrole. The camphene was identified in SDE extracts but not in $CO_2$ extracts. The volatile components of SDE extracts and solvent extracts contained large amount of monoterpene and terpene alcohol but $CO_2$ extracts aminly contained aromatic compounds.

• Korean Journal of Food Science and Technology
• /
• v.37 no.2
• /
• pp.183-188
• /
• 2005

Effects of co-solvent polarity, citric acid, pressure, temperature, run time, and co-solvent ratio on extraction of major flavonoids from Lonicera Flos were investigated using supercritical fluid $CO_{2}(SF-CO_{2})$. HPLC analysis revealed addition of pure methanol resulted in low extraction yield of major flavonoids, luteoloin (Lu), Quercetin (Qu), Apigenin (Ap). Under same condition, as co-solvent polarity increased, yields of major flavonoids increased gradually, At optimum co-solvent extraction condirion of 60% aqueous methanol (10%, v/v), yields of Lu, Qu, and Ap were 42.09, 28.18, and 3.49 mg/100 g, respectively. Addition of citric acid to 60% aqueous methanol gave higher, with addition of 1% citrie acid resulting in highest yields of 63.2 (Lu), 39.35 (Qu), and 5.79 (Ap) mg/100 g. Optimum extraction conditions of major flavonoids were 200 bar, $50^{\circ}C$, 60 min, and $CO_{2}$-methanol-water(20: 1.8: 1.2).