• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.40-45
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• 2001

This study was conducted to investigate the effects of various emulsifiers on the quality of the waxy rice cake. Falling numbers of the waxy rice flour with monoglyceride, lecithin and control were not significantly different, but with sugar esther 0.5% and 1% showed higher value as 88.4 and 81 than control Initial pasting temperature of the waxy rice flour was 66.78$\^{C}$ and others were 66.45 ∼ 67.05$\^{C}$ by adding 0.5%, 1% of emulsifiers such as monoglyceride, lecithin, sugar esther. Waxy rice flour with 1% sugar ester showed the highest peak viscosity as like as falling number. Waxy rice cake wish various emulsifiers showed tendency to be slowly firming rate as compared with control. In all case, waxy rice flour with sugar ester 1% was considered to be more effective to the decrease of firming rate. Waxy rice flour with lecithin showed worse visual color than others and sugar ester provided best visual and sensory quality. After 5 days cold storage, waxy rice flour with sugar ester 1%\`s Aw was 0.875 and control\`s 0.911. These results suggested that water holding capacity of sugar ester was the best during storage.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.834-841
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• 2005

Polyethylene glycol esters (PEG-esters) were synthesized by condensation reaction of dicarboxylic acid such as adipic acid and sebacic acid and several PEGs. The PEG-esters were analyzed by FT-IR, $^1H-NMR$ and HPLC for structure analysis, and by GPC for molecular weight. Through the analysis of surface tension, critical micelle concentration (CMC), aluminum contact angle of water solution containing the PEG-ester, the synthetic PEG-esters are proven to exhibit surfactant properties. The surface tension ranged from 45 to 50 dyn/cm depended on the concentration and structures of the PEG-esters. The surface tension of PEG-esters with sebacic acid moiety and short polyoxyethylene unit resulted in lower value than that of PEG-ester with adipic acid moiety and long polyoxyethylene unit. The CMC of water solution containing 2.5 wt% PEG-ester with sebacic acid moiety estimated at $0.9{\times}10^{-5}{\sim}5.3{\times}10^{-3}mol/L$ depended on the structures of PEG-esters. The CMC of PEG-esters with long polyoxyethlene unit showed a higher value than that of PEG-esters with short polyoxyethylene unit. Meanwhile, the CMC of PEG-esters with adipic acid moiety was not distinct due to their high hydrophilic character. As the results of contact angle and cutting time aginst aluminum, the contact angle ranged from $45^{\circ}$ to $53^{\circ}$ depended on the concentration of PEG-esters. The cutting time of aluminum showed the shortest value at CMC, but the longest value above CMC. This fact indicates that the CMC of PEG-esters is a very important factor in drilling aluminum.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.356-360
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• 1980

Octahedral Co(Ⅲ) complexes of the glycine methyl ester have been prepared and characterized by elemental analysis, infrared, and NMR spectrum. Co(Ⅲ) glycine methyl ester complex has been isolated from the reaction of glycine and glycine methyl ester in aqueous solution by cation exchange resin, Dowex 50W-X8 (hydrogen form). It has been observed that the complexes have $C_1-cis(0-0), C_2-cis(0-0), trans(0-0)$ geometry.

• Korean Journal of Environmental Agriculture
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• v.4 no.2
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• pp.114-117
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• 1985

A new method for micro-quantification of abscisic acid from plant tissue is described. GLC-ECD method of abscisic acid pertafluorobenzyl ester synthesized by reaction of plant extract with pentafluorobenzyl bromide showed higher sensitivity than that of abscisic acid methyl ester, and the detection limit of abscisic acid by the described method was as low as 5 pg.

• Journal of Pharmaceutical Investigation
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• v.17 no.4
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• pp.183-188
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• 1987

A new cephalosporin derivative, cefoperazone phthalidyl ester, were synthesized and investigated in terms of dissolution and absorption properties. In comparison with cefoperazone, its phthalidyl ester showed the following characteristics. The mean dissolution time and variance of retention time were more significantly prolonged in simulated intestinal fluid than those in simulated gastric fluid. After a single oral dosing of both cefoperazone and its ester to rabbits, serum concentrations of cefoperazone were measured by bioassay, and the results showed that the ester exhibited much higher and more sustained blood level than the parent drug. The total area under the curve of cefoperazone phthalidyl ester were 10.8 times greater than that of cefoperazone.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.269-273
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• 1997

This research aims at developing a new plant growth inhibitors related to abscisic acid by means of esterification of (S)-(+)-ABA with p-hydroxy methyl cinnamate and umbelliferone, and testing its biological activity on growth of rice seedlings. The over-all yield of ABA-methyl cinnamate(AC) and ABA-umbelliferone(AC) ester compounds were 83% and 78%, respectively. The growth inhibition activity of these synthetic compounds were shown about 3 to 10 times(AC) and 10 to 30 times(AU) higher than (S)-(+)-ABA.

• Journal of the Korean Chemical Society
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• v.10 no.1
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• pp.4-10
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• 1966

A new method of cobalt determination has been developed by employing ethylenediamine tetrabutyl acetate(EDTA-butyl ester) synthesized from EDTA and Butyl alcohol. The synthesized EDTA ester dissolved in butyl alcohol extracts various metal ions from aqueous solutions. Cobaltous ion extracted into organic phase containing EDTA ester to form Co (II)-EDTA butyl ester complex is back extracted into alkaline aqueous phase forming a stable pink colored complex of Co (III). The optimum condition for spectrophotometric determination of cobalt via the new complex has been established. The absorption peak occurs at 540$m{\mu}$ and Beer's law was obeyed over the concentration range of 0∼50 ${\mu}g/ml$ of cobalt.

• Archives of Pharmacal Research
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• v.19 no.1
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• pp.66-70
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• 1996

Aliphatic esters of protocatechuic acid (PA, 1), vanillic acid (VA, 9) and gallic acid (GA, 18) were prepared and their anti-thrombotic effects were evaluated in the mouse model of thrombosis. The aliphatic groups included methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, n-amyl and cyclohexyl. n-Amyl ester of PA (7), i-propyl and cyclohexyl esters of VA (13 and 17 respectively) and ethyl ester of GA (20) treatment significantly lowered the death rate and increased the recovery from paralysis due to the thrombotic challenge. From the limited analogs available, it was tentatively concluded that the structural conformation, where carboxy oxygen (=O or -O) of the carboxyl group (COOH) at $C_1$ and the oxygen function at $C_3(either\; OH\; or\; OCH_3)$ are closely situated, is favorable for the esters of PA, VA and GA to be more antithrombotic.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.589-594
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• 2009

We have performed DFT B3LYP/6-31G(d,p) calculations to investigate the complexation behaviors of the ethyl ester derivative of p-tert-butylcalix[6]arene (1) toward a variety of alkylammonium ions. We have studied the binding sites of these host-guest complexes focusing on the p-tert-butylcalix[6]arene pocket (endo) of 1. The smaller alkylammonium cations have the better complexation efficiency than the bulkier alkylammonium ions with the p-tert-butylcalix[6]aryl ester. The hydrogen-bonding of N-H$\ldots$O is one of the important factors for the complexation behavior of the p-tert-butylcalix[6]aryl ester, in addition to the NH-aromatic π, CH-aromatic π and electrostatic interactions, and the steric hindrance of alkylammonium cation. The hydrogen-bonded distances and angles of N-H$\ldots$O are reported for the complexes of the p-tert-butylcalix[6]aryl ester with various alkylammonium ions.

• Journal of Pharmaceutical Investigation
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• v.18 no.4
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• pp.197-201
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• 1988

Pivaloyloxymethyl ester of cefoperazone was synthesized by treating sodium cefoperazone with chloromethyl pivalate and its chemical structure was determined by spectroscopic trials. The pharmaceutical properties of the ester were investigated to assess its potential as a prodrug of cefo perazone. Cefoperazone pivaloyloxymethyl ester was microbiologically inactive itself in vitro, but hydrolyzed into the parent drug in vivo. After a single oral dose of each drug to rabbits, serum concentrations of cefoperazone were determined by high performance liquid chromatographic assay. The ester showed higher and more sustained blood level than cefoperazone. Therefore, the total area under the serum concentration-time curve of the derivative was 16.8 times larger than that of the parent drug.