• Applied Biological Chemistry
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• v.22 no.4
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• pp.198-209
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• 1979

L-Tyrosine, 2-chloro-L-tyrosine, 2-bromo-L-tyrosine, and 2-iodo-L-tyrosine were synthesized by ${\beta}-tyrosinase$ obtained from cells of Escherichia intermedia A-21, through the reversal of the ${\alpha},{\beta}-elimination$ reaction, and their molecular structures were analyzed by element analysis, NMR spectroscopy, mass spectrometry and IR spectroscopy. Rates of synthesis and hydrolysis of halogenated tyrosines by ${\beta}-tyrosinase$, inhibition of the enzyme activity by halogenated phenols, and effects of addition of m-bromophenol on the synthesis of 2-bromotyrosine were determined. The results obtained were as follows: 1) In the synthesis of halogenated tyrosines, the yield of 2-chlorotyrosine from m-chlorophenol were approximately 15 per cent, that of 2-bromotyrosine from m-bromophenol 13.8 per cent, and that of 2-iodotyrosine from m-iodophenol 9.8 per cent. 2) Rate of synthesis of halogenated tyrosines by ${\beta}-tyrosinase$ was slower than that of tyrosine and the rates were decreased in the order of chlorine, bromine and iodine, that is, by increasing the atomic radius. Relative rate of 2-chlorotyrosine synthesis was determined to be 28.2, that of 2-bromotyrosine to be 8.13, and that of 2-iodotyrosine to be 0.98, respectively, against 100 of tyrosine. However 3-iodotyrosine was not synthesized by the enzyme. 3) The relative rate of 2-chlorotyrosine hydrolysis by ${\beta}-tyrosinase$ was 70.7, that of 2-bromotyrosine was 39.0, and that of 2-iodotyrosine was 12.6 against 100 of tyrosine, respectively. The rate of hydrolysis appeared to be decreased in the order of chlorine, bromine and iodine, that is, by increasing the atomic radius or by decreasing the electronegativity. But 3-iodotyrosine was not hydrolyzed by the enzyme. 4) The activity of ${\beta}-tyrosinase$ was inhibited by phenol markedly. Of the halogenated phenols, o-, or m-chlorophenol and o-bromophenol gave marked inhibition on the enzyme action, however inhibition by iodophenol was not strong. Plotting by Lineweaver-Burk method, a mixed-type inhibition by m-chlorophenol was observed and its Ki value was found to be $5.46{\times}10^{-4}M$. 5) During the synthesizing reaction of 2-bromotyrosine by the enzyme, sequential addition of substrate which was m-bromophenol with time intervals and in a small amount resulted in better yield of the product. 6) The halogenated tyrosines which were produced by ${\beta}-tyrosinase$ from pyruvate, ammonia and m-halogenated phenols were analysed to determine their molecular structures by element analysis, NMR spectroscopy, mass spectrometry, and IR spectroscopy. The result indicated that they were 2-chloro-L-tyrosine, 2-bromo-L-tyrosine, and 2-iodo-L-tyrosine, respectively.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.224-229
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• 1981

Perilla (Perilla frutescens Britton var. Crispa Decasne) cultivated in three geographical areas of Korea, Gwangju, Taegu and Jeju, was analyzed for carbohydrate, lipid, protein, inorganic components and fatty acid composition. Carbohydrate, lipid and protein content of perilla seed ranged from 40 (Taegu) to 44% (Jelu), from 28 (Jeju) to 34% (Taegu) and from 15 (Gwangju) to 16% (Jeju), respectively. The overage contents of potassium, silicate, calcium, phosphate, iron, zinc, magnesium and mangane in the perilla seed varied between $426{\sim}446$, $197{\sim}229$. $124{\sim}136$, $46{\sim}56$, $30{\sim}49$, $42{\sim}45$, $40{\sim}45$, and $30{\sim}36mg%$, respectively and those variations different cultivation areas were not significant except iron. Saponification number, iodine value and acid value of the perilla oil were between $194{\sim}198$, $196{\sim}200$ and $4{\sim}5$, respectively. Those variations among the cultivation areas were not significant. The composition of the perilla oil was observed to be composed of $92{\sim}95%$ of triglyceride, $1.2{\sim}1.3%$ of phospholipid, $1.7{\sim}1.9%$ of unsaponifiables, $0.7{\sim}0.9%$ of free fatty acid, and $1.1{\sim}1.4$ linolenic, linoleic and oleic acid as $55{\sim}56$, $16{\sim}18$ and $16{\sim}20%$ of total fatty acids, but in phospholipid, the content of saturated fatty acids, $12{\sim}24$ of total fatty acid, was higher than that in triglyceride, $8{\sim}19%$ of total fatty acids. The content of saturated fatty acids in sterylester $(14{\sim}19%)$ was higher than that in sterylglycoside ($6{\sim}7%$ of total fatty acids). The variation in fatty acid composition was not significant in the composition of total fatty acid but a significant difference was observed in the composition of phospholipid, in which the content of palmitate ranged from 11.8%(Taegu) to 24%(Gwangju) of total fatty acids. No significant variation was found in the fatty acid composition among the cultivation areas, while a significant difference was observed in phospholipid.

• Applied Biological Chemistry
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• v.19 no.1
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• pp.36-40
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• 1976

The mucilage of the root of Abelmoschus manihot, MEDIC is important for production of Korean traditional hand-made paper. This study was proceeded to detect the variation of the amount of free reducing sugars and of the viscosity in the mucilage. The results as follow. 1. The mucilage of the root of Abelmoschus manihot, MEDIC has contained some of free reducing sugars, 2. The viscosity of the mucilage isolated from the root decreases with time at the constant temperature, but the amount of reducing sugars show a little change. 3. The amount of the reducing sugars is not changed on the agitation. 4. When $1{\sim}2%$ ammonium sulfate solution is added, the viscosity of the mucilage decreases very gradually, and the amount of the free reducing sugars in the mucilage shows a little change.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.245-251
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• 1985

In order to analyze the lipid composition ana chemical characteristics of rapeseed oil in relation to content of erucic acid, three recommendable cultivars(MOK-PO 70, MOK-PO DANGYO 12 and 14) seeds were used. The composition of lipid was confirmed by column chromatography and TLC, and the composition of fatty acid in total and neutral lipid was determined by GLC, and the results were as follows. 1. The crude fat was 44.0% to 45.3% in all cultivars. 2. The iodine value, saponification value, acid value and nonsaponifiable content were 100 to 101, 176 to 184, 0.7 to 0.9 and 1.0 to 1.2, respectively, with no remarkable difference among three cultivars. 3. The content of neutral lipid was 95.3% to 96.3% of total lipid, and others were compound lipids. 4. The content to triglyceride was 92. 1% to 92.5% of total lipid. Diglyceride and sterol ester were contained 1.1% and 1.2%, respectively. There was a small quantity of free fatty acid and free sterol and monoglyceride was little. 5. The erucic acid was the highest (26.4%), in MOK-PO DANGYO 12 among the composition of fatty acid, while those of MOK-PO 70 and MOK-PO DANGYO 14 were so small as 1.0% and 3.9%. The content of erucic acid was decreased with the increase of oleic acid, the content of oleic acid in MOK-PO DANGYO 12 was 30%, 63% in MOK-PO 70 and, 60% in MOK-PO DANGYO 14. The content of linoleic acid and linolenic acid showed no remarkable difference but that of eicosenoic acid was 11.7% in MOK-PO DANGYO 12 as the highest. The ratio of the fatty acid content in eluted neutral lipid and the total oil showed no remarkable differences.

• Applied Biological Chemistry
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• v.15 no.1
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• pp.65-75
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• 1972

The rice qualities including cooking and eating qualities were studied using recommended Korean rice varieties (20 of japonica and 3 of indies type; IR 667) which were grown at Suwon, Korea in 1971. As the result, followings were obtained. 1. Amylose contents of white rice were varied with the varieties 21.1 to 25.5% and the average was 23.0%. Three indica type varieties (IR 667) showed higher amylose contents than the other japonica type varieties except Mankyung. Among japonica type varieties, Palkum, Mankyung composed the group of the highest amyloes content and Kimmaje was the lowest. 2. Blue values were distributed in the range of 0.38 to 0.48 and the average was 0.42 IR 667 varieties showed the highest blue value among them. Among japonica type varieties, Jaegun showd the highest blue value and Sooseung, Shirogane showed successively lower values, Shin #2, Nongbaik, Palkweng, Suwon #82, Mankyung, Nonglim #25 and Nongkwang relatively lower blue values. 3. Alkali numbers were in the range of 6.0 to 7.4 and the average was 6.8. Much difference was not shown in alkali number between IR 667 group and the japonica varieties group. 4. Gelatinization temperature were ranged from 59.5 to 64.0 IR 667 varieties showed relatively higher gelatinization temperature than japonica type varieties. 5. Water uptake ratios were measured in the range of 2.67 to 2.92 and the average was 2.79. IR 667 varieties were belonged to the group of highest water uptake ratio. Among japonica type varieties Kimmaje, Suwon #82, Nonglim #29, Deungpan #5, Jaegun, Jinhung, were belonged to the group of relatively high water uptake ratio and Palkweng, Palkeum and Paldal to the relatively low water uptake ratio. 6. Expaned volums were ranged from 29.8 to 33.7 and the average was 31.8. IR 667 varieties showed higher expanded volumes than japonica type varieties. 7. Intensities of starch-iodine blue value of residual liquid indicated 0.35 to 0.58. Among them IR 667 varieties showed relatively high intensities. 8. The range of total solids in residual liquids was 0.605 to 0.810 and the average was 0.700 Much difference was not shown in total solids in residual liquid between IR 667 varieties and japonica varieties. 9. pH values of residual liquids were in the range of 6.3 to 7.3 and the average was 6.95. IR 667 varieties showed lower pH than japonira type varieties.

• The Korean Journal of Nuclear Medicine
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• v.38 no.1
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• pp.41-51
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• 2004

PURPOSE: Tourette's disorder (TD), which is characterized by multiple waxing and waning motor tics and one or more vocal tics, is known to be associated with abnormalities in the dopaminergic system. To testify our hypothesis that risperidone would improve tic symptoms of TD patients through the change of the dopaminergic system, we measured the dopamine transporter (DAT) densities between drug-naive children with TD and normal children, and investigated the DAT density before and after treatment with risperidone in drug-naive children with TD, using iodine-123 labelled $N-(3-iodopropen-2-yl)-2{\beta}-carbomethoxy-3beta-(4-chlorophenyl)tropane$ ($[^{123}I]IPT$) single photon omission computed tomography (SPECT). MATERIALS and METHODS: $[^{123}I]IPT$ SPECT Imaging and Yale Global Tic Severity Scale-Korean version (YGTSS-K) for assessing the tic symptom severity were carried out before and after treatment with risperidone for 8 weeks in nine drug-naive children with TD. Eleven normal children also underwent SPECT imaging 2 hours after an intravenous administration of $[^{123}I]IPT$. RESULTS: Drug-naive children with TD had a significantly greater increase in the specific/nonspecific DAT binding ratio of both basal ganglia compared with the normal children. However, no significant difference in the specific/nonspecific DAT binding ratio of the basal ganglia before and after treatment with risperidone in children with TD was found, although tic symptoms were significantly improved with risperidone. CONCLUSION: These findings suggest that DAT densities are directly associated with the pathophysiology of TD, however, that the effect of risperidone on tic symptoms in children with TD is not attributed to the change of dopaminergic system.