• BMB Reports
• /
• 제28권2호
• /
• pp.124-128
• /
• 1995

Biodegradative threonine dehydratase purified from Serratia marcescens ATCC 25419 was inactivated by the arginine specific modification reagent, phenylglyoxal (PGO) and the lysine modification reagent, pyridoxal 5'-phosphate (PLP). The inactivation by PGO was protected by L-threonine and L-serine. The second order rate constant for the inactivation of the enzyme by PGO was calculated to be 136 $M^{-1}min^{-1}$. The reaction order with respect to PGO was 0.83. The inactivation of the enzyme by PGO was reversed upon addition of excess hydroxylamine. The inactivation of the enzyme by PLP was protected by L-threonine, L-serine, and a-aminobutyrate. The second order rate constant for the inactivation of the enzyme by PLP was 157 $M^{-1}min^{-1}$ and the order of reaction with respect to PLP was 1.0. The inactivation of the enzyme by PLP was reversed upon addition of excess acetic anhydride. Other chemical modification reagents such as N-ethylmaleimide, 5,5'-dithiobis (2-nitrobenzoate), iodoacetamide, sodium azide, phenylmethyl sulfonylfluoride and diethylpyrocarbonate had no effect on the enzyme activity. These results suggest that essential arginine and lysine residues may be located at or near the active site.

• 한국응용약물학회:학술대회논문집
• /
• 한국응용약물학회 1996년도 춘계학술대회
• /
• pp.255-255
• /
• 1996

Flavonoids are the large class of plant-derived polyphenolic compounds with a broad spectrum of biological actions including anti-inflammatory, anti-allergic and anti-asthmatic activities. It has been reported that quercetin and some other flavonoids inhibit the histamine release from mast cells. Disodium cromoglycate, a kind of biflavonoid, have been used as a anti-asthmatic agent. Therefore, the following study was undertaken to characterize tile structure-activity relationships of flavonoids in the inhibition of histamine release, from IgE-sensitized mast cells. Flavonoid acetate were synthesized by addition of acetic anhydride to the flavonoids dissolved in pyridine. According In the Mota method, IgE-rich serum was made in rats sensitized with Pertussis vaccine and ovalbumin. Rat abdominal mast cells were harvested and purified over tile discontineous Percoll gradients, Mast cells were preincubated in RPMI with IgE-rich serum and further incubated with flavonoids. Histamine contents released from mast cells were determined fluorospectrophotometrically after stimulation with ovalbumin. (omitted)

• Journal of Pharmaceutical Investigation
• /
• 제36권2호
• /
• pp.115-121
• /
• 2006

The aim of this study was to develop new protein/peptide depot system instead of poly(DL-lactic acid-coglycolic acid) (PLGA) microspheres. Pullulan was chemically modified by the addition of acetic anhydride (pullulan acetate; PA) and then investigated as new depot system for protein/peptide delivery. PA microspheres (PAM) with lysozyme as a model protein were prepared by w/o/w double emulsion method. The microspheres had a mean size of 10-50 mm with a spherical shape. The size distributions reduced with increasing the degree of acetylation. The loading efficiency of lysozyme was also increased. Lysozyme aggregation behavior in the microsphere was monitored to estimate the change of protein stability during preparation step. The ratios of protein aggregation in PAMs are lower than that of PLGA microsphere, in particular, PA 5 showed lowest as about 16%. The result indicated that the increase of acetylation suppressed the aggregation of protein. The release profiles of lysozyme from PAMs were significantly different. High acetylation effectively improved lysozyme release kinetics by reducing initial burst release and extending continuous release over a period of time. To check the effect of preservation for structural stability of lysozyme, the activity of lysozyme released from PA 5 was also observed. The activity of lysozyme was maintained almost 100% for 25 day. Therefore, PAM may become to a useful carrier for delivery of protein/peptide drugs, if it will be supported by biocompatibility and biodegradability results.

• Bulletin of the Korean Chemical Society
• /
• 제28권12호
• /
• pp.2324-2328
• /
• 2007

Organic fluorine chemistry produces many useful products. This paper elucidates the reaction of ethyl-4,4- difluoro-2-iodo-5-oxo-5-phenylpentanoate (2) with primary amines in a one-pot scheme. The reaction produced a series of β-fluoropyrrole derivatives at ambient temperatures. In this reaction, the less bulky the primary amine the higher was the resultant yield. When (2) and aqueous methylamine (40%) were allowed to react below 0 oC, 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2-hydroxy-2-phenylpyrrolidine, an intermediate molecule for 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2-carboxylate (5), was isolated first. Then, (5) reacted with hydroperchloric acid and acetic anhydride to form 5-(ethoxycarboxyl)-1-methyl-3,3-difluoro-2- phenylpyrrolinium perchlorate (6), which was converted to 2-ethyl-4-flouro-1-methyl-5-phenylpyrrole-2- carboxylate gradually in the presence of a base. Our experiments demonstrate that the formation of 2-ethyl-4- flouro-1-methyl-5-phenylpyrrole-2-carboxylate occurs via both one-pot schemes and stepwise pathways, depending on the reaction conditions. The isolation and characterization of the isolated intermediate (6) suggest an anionic pathway for this reaction.

• 약학회지
• /
• 제36권3호
• /
• pp.230-240
• /
• 1992

The metabolic profile of doxylamine, N,N-dimethyl-2-[1-phenyl-1-(2-pyridinyl)ethoxy] ethanamine, was determined in the human urine. The free fractions of extracts were obtained without hydrolysis, and the conjugated fractions of extracts were obtained with enzyme hydrolysis using ${\beta}-glucuronidase/arylsulfatase$ from Helix pomatia. The mixture of acetic anhydride/pyridine (10 : 1, v : v) was used to derivatize the urinary extracts and then analyzed by gas chromatography and mass selective detector. N-desmethyldoxylamine, doxylamine carboxylic acid, desaminohydroxydoxylamine, N, N-didesmethyldoxylamine, N-acetyl conjugates of N-desmethyl and N, N-didesmethyldoxylamine, quarternary ammonium N-glucuronide of doxylamine, N-desmethyldoxylamine N-glucuronide and unchanged doxylamine were detected in the human urine obtained after oral treatment with doxylamine succinate. $N-methyl-{\alpha}-hydroxy-2-[1-phenyl-1-(2-pyridinyl)$ ethoxy] ethanamine, which can be a key intermediate of this metabolism, was tentatively identified by the interpretation of its mass spectrum. In this study, we proposed the metabolic pathway of doxylamine in the human on the basis of our data of the identified metabolites of doxylamine.

• 한국의류산업학회지
• /
• 제8권2호
• /
• pp.233-238
• /
• 2006

This research confirmed the chemical structure of Curcumine and Carthamin pigments whose pigments were separated and refined from the Curcuma longa and Carthamus Tinctorious which were natural dye using FT-IR, HPLC and so on. The cotton and the silk fabrics were dyed using a main pigment and then this research obtained the conclusion as it follows. The curcumine, the main pigment of Curcuma longa extracted from the mixed solvent of acetic anhydride and methanol ($CH_3OH$), had the maximum absorption wavelength at 504.0 nm and was confirmed as yellow natural pigment. The Carthamin, the main pigment of Carthamus Tinctorious extracted from the mixed solvent of dichloromethane and methanol, had the maximum absorption wavelength at 420.0nm. This pigment was confirmed as yellow natural pigment. The dyeing property of the main pigment about the silk fabrics was superior to that about the cotton in both the Curcuma longa and Carthamus Tinctorious, and the dyeing property of Carthamus Tinctorious was superior to that of Curcuma longa.

• Journal of the Korean Wood Science and Technology
• /
• 제42권2호
• /
• pp.183-192
• /
• 2014

For the structure determination of D-(+)-sucrose, which consists of ${\alpha}$-D-(+)-glucose and ${\beta}$-D-(+)-fructose, it was acetylated with acetic anhydride and triethyl amine, pyridine, zinc chloride, and sodium acetate as catalysts. The acetylated D-(+)-sucrose was acid-hydrolyzed using sulfuric acid and sodium chloride in methanolic solution. The structures of the reaction products were determined by $^1H$-NMR and $^{13}C$-NMR spectra. The yield of the acetylation indicated the high value in zinc chloride as 70% in zinc chloride catalyst. The acid-hydrolyzed product of the acetylated D-(+)-sucrose, 2,3,4,6,1',3',4',6'-octa-O-acetyl-D-(+)-sucrose, gave 2,3,4,6-tetra-O-acetyl-${\beta}$-D-(+)-glucose and it suggests that the acetylated D-(+)-sucrose was rearranged through the formation of oxonium ion by mutarotation in the 2,3,4,6-tetra-O-acetyl-${\alpha}$-D-(+)-glucose moiety and through the ring opening in the 1',3',4',6'-tetra-O-acetyl-${\beta}$-D-(+)-fructose moiety.

• 한국식품영양학회지
• /
• 제2권1호
• /
• pp.18-26
• /
• 1989

The objective of this study was to improved the limited functional characteristics of mungbean whole globulin. The mungbean whole globulin was acylated with succinic and acetic anhydride, and the functional properties of acylated protein were investigated, The results obtained ware as follows. 1. The UV-absorption spectra of acylated whole globulins with that of the succinylated 74% whole globulin as large blue shift of the absorption maximum and minimum wavelength from 275 nm to 269 nm, respectively. 2. The mobility of acylated whole globulin were increased on PAGE pattern, and degree of mobility was particularly remarkable in case of succinylation, 3. The water absorption capacity of whole globulin was increased by acylation. The most increased rate of whole globulin was 174,02% from succinylated 74%. The oil absorption capacity of whole globulin was increased by acylation The most increased rate of whole globulin was 165.41% from acetylated 81.77%. 4. The bulk density of whole globulin was decreased by acylation. and the greater the extent of acylation, the smaller the bulk density. 5. The foaming capacity and stability of whole globulin was increased by acylation, and remarkably high in 74% succinylated whole globulin. In contrast, however, the foaming capacity and stability of native and acylated whole globulin were decreased by heat treatment.

• 대한화학회지
• /
• 제56권3호
• /
• pp.348-356
• /
• 2012

In an attempt to find a new class of bisazo disperse dyes with better dyeing properties, a series of novel bisazo dyestuffs based on 4-arylhydrazono-3-(2'-hydroxyphenyl)-1-phenyl-2-pyrazolin-5-ones $\mathbf{3a-f}$ were prepared by diazocoupling of p-nitrophenyl diazonium chloride with 4-arylhydrazono-3-(2'-hydroxyphenyl)-1-phenyl-2-pyrazolin-5-ones $\mathbf{2a-f}$. Compounds $\mathbf{3a-f}$ were subsequently reacted with acetic anhydride in the presence of p-toluenesulfonic acid afford the corresponding O-acetyl derivatives $\mathbf{4a-f}$. The latter products as well as spectral data indicated that compounds $\mathbf{3a-f}$ exist predominantly in the azo-hydrazone tautomeric form (H) as the ZE-configuration. Additionally, two series of the synthesized dyes $\mathbf{3a-f}$ and $\mathbf{4a-f}$ were applied as disperse dyes for dyeing polyester fabrics and their fastness properties were evaluated. Also the position of color in CIELAB coordinates ($L^*$, $a^*$, $b^*$, $H^*$, $C^*$*) was assessed.

• Advances in nano research
• /
• 제14권2호
• /
• pp.201-210
• /
• 2023

A ZnO/poly (amide-imide) hybrid nanocomposite film with different weight percentages of Zinc oxide (ZnO) nanoparticles is synthesized and characterized in this paper. A two-step reaction successfully synthesized a new kind of heteroaromatic diamine with bulky pendant groups. In order to produce 3, 5-dinitro-3, 3-bis (4-(4-Nitrophenoxy) phenyl) -2- benzofuran-1-one, 3, 3'-bis (4-hydroxyphenyl) benzofuran-1-one and 3'-bis (4-hydroxyphenyl) benzofuran-1-one were combined with 3'-bis (3-hydroxyphenyl) benzofuran-1-one. The obtained dinitro was then reduced by zinc dust and hydrochloric acid. The reaction of 4, 4^* carbonyl diphthalic anhydride with amino acid L-alanine in acetic acid leads to the production of very high yields of chiral diacid monomer. As a result of the direct polymerization of these monomers, new optically active polymers were formed (amide-imide). In order to synthesize poly (amide-imide)/ZnO nanocomposites with different weight percentages (2, 4, 6, 8, and 10%), PAI and ZnO nanoparticles were combined using ultrasonication SEM, Fourier transform infrared spectroscopy, X-ray diffraction and thermal gravimetry were used to characterize the PAI films.