• YAKHAK HOEJI
• /
• v.28 no.4
• /
• pp.197-206
• /
• 1984

The derivatives of N-(alkylcarbamoyl) amino acid methyl ester, N-(2-chloroethylcarbamoyl)-glycine methyl ester (7a), -valine methyl ester (8a), -phenylalanine methyl ester (9a), N-(N'-methylcarbamoyl)-glycine methyl ester (7b), -valine methyl ester (8b), and-phenylalanine methyl ester (9b), were prepared by reacting the corresponding free amino acid methyl ester (glycine-, valine-, phenylalanine-methyl ester) with isocyanate (R-N=C=O${\cdot};R=Cl-CH_2-CH_2-or\; CH_3-)$. The prepared N-(alkylcarbamoyl) amino acid methyl esters (7,8,9) were treated with $NaNO_2$/98% HCOOH in order to obtain their nitrosoated products, N-(alkyl-N'-nitrosocarbmoyl)amino acid methyl ester. The compound (7,8,9) gave N-(2-chloroethyl-N'-nitrosocarbamoyl)-valine methyl ester (14a),-phenylalanine methyl ester (15a), N-(N'-alkyl-N'-nitrosocarbamoyl)-glycine methyl ester (13b),-valine methyl ester. (14b), and-phenylalanine methyl ester (15b) respectively under the nitrosoation. On the other hand, N-(2-chloroethylcarbamoyl) glycine methyl ester produced N-(2-chloroethylcarbamoyl)-N-nitrosoglycine methyl ester (13a). The inhibitory activity of the prepared N-(alkylcarbamoyl) amino acid methyl ester (7,8,9) and N-(alkyl-N'-nitrosocarbamoyl) amino acid methyl ester (13,14,15) towards the growth of L1210 murine leukemia cells were examined. Among them the compound (14a) and (15a) exhibit excellent activity having $ED_{50}\; to\;be\;1.5{\mu}g/ml\;and\;3.0{\mu}g/ml respectively.

• Journal of the Korean Chemical Society
• /
• v.19 no.3
• /
• pp.169-173
• /
• 1975

Ten previously unreported dipeptides ontaining aminobenzylphosphonic acid were prepared by carbodiimide method. These are; Glycyl-dl-1-aminobenzylphosphonic acid, alanyl-dl-1-aminobenzylphosphonic acid, L-alanyl-dl-1-aminobenzylphosphonic acid, N-phthalyl-L-phenylalanyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxyglycyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxyalanyl-dl-1-aminobenzylphosphonic acid diethyl ester, N-carbobenzoxy-L-alanyl-dl-1-aminobenzylphosphonic acid diethyl ester, glycyl-dl-1-aminobenzylphosphonic acid diethyl ester hydrobromide, alanyl-dl-1-aminobenzylphosphonic acid diethyl ester hydrobromide and L-alanyl-dl-1-aminobenzylphosphonic acid diethyl ester hydrobromide. The first six compounds were characterized, and the last four compounds were obtained in the crude state.

• Journal of the Korean Chemical Society
• /
• v.24 no.1
• /
• pp.15-19
• /
• 1980

CNDO/2, EHT molecular orbital methods are used to investigate the electronic structure and reactivity of glycinato, glycine ester ligands. The results show that bidentate glycinato has a more stable structure, Gly-I with a $105.9^{\circ}$dihedral angle between ${\Delta}O_4C_3C_2$ and ${\Delta}C_3C_2N_1$ than Gly-Ⅱ. The electron inductive effects in the alkyl group substituted glycine ester ligands can also be derived from the calculation. According to the electron density, qN of ligands on the basis of CNDO/2 MO calculations, it is concluded that the stabilities are in the order of glycinato > Gly-Et-ester > Gly-i-Pr-ester > Gly-Me-ester.

• Textile Coloration and Finishing
• /
• v.15 no.4
• /
• pp.24-31
• /
• 2003

In this research, we applied FT-IR spectroscopy to study the hydrolysis of the ester-crosslinking formed by various polycarboxylic acids on the cotton fabric. We observed the following; (1) the ester-crosslinking is less durable to hydrolysis than ether-crosslinking under all conditions; (2) the ester-crosslinking formed by polycarboxylic acids having more than three carboxyl groups, such as butanetetracarboxylic acid (BTCA), are substantially more durable to hydrolysis than the acids having two or three carboxyl groups, such as maleic and citric acid; (3) alkaline conditions drastically accelerate the hydrolysis of both urea- and ester-crosslinking; and (4) the ester-crosslinking formed by poly(maleic acid) is more resistant to hydrolysis at alkaline conditions than BTCA. (5) polycarboxylic acid molecules were removed from the fabric at same rate as the hydrolysis of the ester linkage. FT-IR spectroscopy has proved to be a useful analytical technique for evaluating the hydrolysis of the crosslinked cotton fabric.

• Journal of Pharmaceutical Investigation
• /
• v.18 no.2
• /
• pp.49-53
• /
• 1988

Pivaloyloxymethyl ester of piperacillin was synthesized by reacting sodium piperacillin with chloromethyl pivalate, and its chemical structure was determined by infrared and $^1H$ nuclear magnetic resonance spectroscopic methods. The pharmaceutical properties of the ester were investigated to assess its potential as a novel prodrug of piperacillin. The interface transfer of piperacillin and the ester was studied in a two-phase in vitro system composed of aqueous pH buffers and n-octanol. The ester was more lipophilic, and less water soluble above pH 4.0 than piperacillin. Significant antibacterial activity was not observed in the ester in vitro, but the ester was hydrolyzed into the parent drug in the rat liver homogenate. The serum levels of orally administered ester suspension containing 0.1% Tween 80 were measured in rabbits. It was found that the ester showed higher blood level, comparing with no observation of piperacillin in serum, but the time reaching the maximum serum concentration was 5 hr.

• KSBB Journal
• /
• v.14 no.2
• /
• pp.220-224
• /
• 1999

Lactic acid was reacted with alcohol into lactate ester, and lactate ester produced in esterification reaction was distilled simultaneously with hydrolysis reaction into lactic acid. When the yields of lactic acid recovered by batch reactive distillations with various alcohols were compared, the yield of lactic acid was increased as the volatility of lactate ester was increased. In this batch reactive distillation, because the mixtures condensed in partial condensor were flown to reboiler through distillation column, the recovery yield of lactic acid was affected by operation temperature of partial condensor. Hydrolysis reaction into lactic acid in distillation column rarelyoccurred because of short retention time of lactate ester and water. Lactate ester was reacted into lactic acid in reboiler.

• Journal of the Korean Chemical Society
• /
• v.20 no.1
• /
• pp.73-86
• /
• 1976

Four unreported derivatives of N-arylsulfonylbenzamide and six derivatives of N-arylsulfonylbenzimidothiophenyl ester were prepared. These were; p-methyl-N-(arylsulfonyl)benzamide, m-methyl-N-(arylsulfonyl)benzamide, m-nitro-N-(arylsulfonyl)benzamide, p-methoxy-N-(arylsulfonyl)benzamide, p-methyl-N-(arylsulfonyl)benzimidothiophenyl esters, p-chloro-N-(arylsulfonyl)benzimidothiophenyl ester, m-methyl-N-(arylsulfonyl)benzimidothiophenyl ester, p-nitro-N-(arylsulfonyl)benzimidothiophenyl ester, m-nitro-(arylsulfonyl)benzimidothiophenyl ester and p-methoxy-N-(arylsulfonyl)benzimidothiophenyl ester. The rate constants of the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters were determined by ultraviolet spectrophotometry at various pH and rate equations which can be applied over a wide pH range were obtained. From the rate equation and substituent effects, one can conclude that above pH 11, the hydrolysis of N-arylsulfonylbenzimidothiophenyl esters are initiated by the attack of hydroxide ion, however, below pH 9, started by the addition of a water molecule on the azomethine group. At pH 9∼11, the competitive reaction between a water molecule and hydroxide ion is anticipated to occur.

• KSBB Journal
• /
• v.22 no.3
• /
• pp.168-173
• /
• 2007

To clarify the usefulness of fluorescent diagnosis for cancer, we investigated the optimal method of administrating 5-aminolevulinic acid (5-ALA), 5-aminolevulinic acid methyl ester (ALA-methyl ester) by analyzing fluorescence signal of Protoporphyrin IX (PpIX) in the cultured normal and cancer cells. 5-ALA and ALA-methyl ester was injected as a photosensitizer to the cancer liver cells (HepG2) and normal liver cells (Chang). Chang and HepG2 cells were incubated with various concentrations of 5-ALA and ALA-methyl ester (0-800 ${\mu}g/mL$). The accumulation of PpIX induced by 5-ALA and ALA-methyl ester was in HepG2 and Chang. The cell viability was measured by MTT assay. Fluorescence of PpIX in HepG2 cell was excited at a wavelength ($\lambda$ = 410 nm) and showed an emission spectrum at 603.2 nm, 660.8 nm and 603.2 nm, 661.4 nm which could be related to the PpIX generation induced by the applied 5-ALA and ALA-methyl ester, respectively. The experimental results showed that fluorescence signal of PpIX was proportional to the concentration of 5-ALA and ALA-methyl ester in tumor cells, but measured with low concentration in normal cells. Another results showed that the PpIX formation rate induced by ALA-methyl ester is higher than that of 5-ALA.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.9
• /
• pp.1224-1231
• /
• 2006

Sucrose esters were synthesized by transesterification of sucrose with docosahexaenoic acid ethylester mixture (DHAEE). Potassium carbonate as a base catalyst was used in the presence of dimethylsulfoxide (DMSO) for the reactions. The reactions were performed with the different reaction times and molar ratios of substrates in the presence of surfactant in vacuum. Among the reaction conditions in this study, SE#4～7 showed the relatively high conversion rate (>96%) of DHAEE, leading to the high yield of sucrose esters. In addition, the product composition was changed from sucrose mono ester to di/tri/polyesters after the prolonged reaction time while the increased molar ratio of DHAEE also resulted in the composition changes of sucrose mono ester to the sucrose di/tri/polyesters. From the reaction (SE#7), conversion ratio was 98.5% in which 87.3% mono ester and 13.7% di/tri/polyester were found, resulting in the highest content of mono ester. Therefore, the sucrose ester containing various rates of mono and di/tri/polyesters, which effects on hydrophilic lipophilic balance (HLB) values, can be manipulatively synthesized using the reaction conditions reported in this study.

• Textile Coloration and Finishing
• /
• v.17 no.3 s.82
• /
• pp.16-25
• /
• 2005

In this research, we investigated hydrolysis of the ester crosslinking on cotton fabric treated with polymer of maleic acid(PMA), citric acid(CA) and combination of polymer of maleic acid and citric acid using Fourier transform infrared spectroscophy. The rate of hydrolysis of the ester crosslinkage increased with pH regardless of the type of polycarboxylic acid used and even after hydrolysis for 256 hour in pH 13_4 solution, the treated fabric retained $10-20\%$ ester crosslinkage. The durability to alkaline hydrolysis of the ester crosslinkage formed by CA was lower than that of by PMA and combination of poly(maleic acid) and citric acid indicating that the ester formed by CA on the cotton fabric is more susceptible to hydrolysis than that formed by PMA and combination of PMA and CA. The total amount of ester and polycarboxylic acid molecules removed from fabric increased with increasing hydrolysis time but the rate of hydrolysis of ester linkage were higher than that of removal of polycarboxylic acid molecule from the fabric. The characteristic of hydrolysis of fabric treated with combination of PMA and CA was related with the mixing ratio of PMA and CA in treating fabric.