Glutathione-dependent biotransformation of the fungicide chlorothalonil     

Kim YM  Park K  Joo GJ  Jeong EM  Kim JE  Rhee IK 《Journal of agricultural and food chemistry》2004,52(13):4192-4196

A gene responsible for the chlorothalonil biotransformation was cloned from the chromosomal DNA of Ochrobactrum anthropi SH35B, capable of efficiently dissipating the chlorothalonil. The gene encoding glutathione S-transferase (GST) of O. anthropi SH35B was expressed in Escherichia coli, and the GST was subsequently purified by affinity chromatography. The fungicide chlorothalonil was rapidly transformed by the GST in the presence of glutathione. LC-MS analysis supported the formation of mono-, di-, and triglutathione conjugates of chlorothalonil by the GST. The monoglutathione conjugate was observed as an intermediate in the enzymatic reaction. The triglutathione conjugate has not been previously reported and seems to be the final metabolite in the biotransformation of chlorothalonil. The glutathione-dependent biotransformation of chlorothalonil catalyzed by the bacterial GST is reported.  相似文献   

Effect of heat treatment on the antioxidant activity of extracts from citrus peels   总被引：1，自引：0，他引：1  

Jeong SM  Kim SY  Kim DR  Jo SC  Nam KC  Ahn DU  Lee SC 《Journal of agricultural and food chemistry》2004,52(11):3389-3393

The effect of heat treatment on the antioxidant activity of extracts from Citrus unshiu peels was evaluated. Citrus peels (CP) (5 g) were placed in Pyrex Petri dishes (8.0 cm diameter) and heat-treated at 50, 100, or 150 degrees C for 10, 20, 30, 40, 50, and 60 min in an electric muffle furnace. After heat treatment, 70% ethanol extract (EE) and water extract (WE) (0.1 g/10 mL) of CP were prepared, and total phenol contents (TPC), radical scavenging activity (RSA), and reducing power of the extracts were determined. The antioxidant activities of CP extracts increased as heating temperature increased. For example, heat treatment of CP at 150 degrees C for 60 min increased the TPC, RSA, and reducing power of EE from 71.8 to 171.0 microM, from 29.64 to 64.25%, and from 0.45 to 0.82, respectively, compared to non-heat-treated control. In the case of WE from CP heat-treated at the same conditions (150 degrees C for 60 min), the TPC, RSA, and reducing power also increased from 84.4 to 204.9 microM, from 15.81 to 58.26%, and from 0.27 to 0.96, respectively. Several low molecular weight phenolic compounds such as 2,3-diacetyl-1-phenylnaphthalene, ferulic acid, p-hydroxybenzaldoxime, 5-hydroxyvaleric acid, 2,3-diacetyl-1-phenylnaphthalene, and vanillic acid were newly formed in the CP heated at 150 degrees C for 30 min. These results indicated that the antioxidant activity of CP extracts was significantly affected by heating temperature and duration of treatment on CP and that the heating process can be used as a tool for increasing the antioxidant activity of CP.  相似文献   

A method for selection of restriction enzymes for sdCAPS marker construction     

YeSol Jeong  SunYoung Lee  InHye Choi  YongPyo Lim  YoonKang Hur  Jack E. Staub  SangMin Chung 《Plant Breeding》2011,130(3):401-403

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Defruiting effect of young Fuyu persimmon (Diospyros kaki) on assimilate partitioning in-season and early growth the next season     

Soo Jeong Park  Young Kee Kim 《Scientia Horticulturae》2011

Changes in the distribution of dry matter and nonstructural carbohydrates in various parts of young ‘Fuyu’ persimmon (Diospyros kaki) were examined with 3- and 4-year-old trees with (fruited) and without fruits (defruited). The effect of such changes was then monitored with regard to the magnitude of new growth the following year. From June 15 to November 1, fruiting significantly decreased the rate of dry weight accumulation in perennial parts of the tree. Dry matter was partitioned the most to fruits (68–72%) and the least to the roots. Of the total dry weight, root accounted for 8–27% in fruited and 58–62% in defruited trees. During this period, soluble sugars were three times more in fruited than in defruited trees, but more than 95% of sugars were in the fruits. Starch content increased in defruited trees, more than 93% of which being distributed to the perennial parts. Compared with fruited trees, defruiting in the previous year increased new shoot growth and the number of fruits the following year, with a 20–58% greater increase in dry matter. During the new growth from April 10 to June 10 the following year, root dry weight decreased by 30–32% in defruited trees, whereas it increased by 20–80% in the fruited ones. Soluble sugars in roots decreased by 8.8–19.7 g in defruited trees but increased by 9.7–12.3 g in fruited ones. Starch in roots decreased by 68–75.1 g in defruited trees but increased by 10.2–13.3 g in fruited ones. However, there were no significant differences in soluble sugars and starch in the newly grown parts. It was estimated that a 1-g difference in dry matter accumulated in the previous season resulted in a 116-mg and 256-mg difference in dry weight of newly grown parts, and a 6.5-mm and 17.5-mm new shoot in the following season for 3- and 4-year-old trees, respectively.  相似文献   

Dry weight and carbohydrate distribution in different tree parts as affected by various fruit-loads of young persimmon and their effect on new growth in the next season     

Soo Jeong Park 《Scientia Horticulturae》2011

This study was conducted to determine the changes in the accumulation of dry weight (DW) and the distribution of carbohydrates in different parts of young persimmon (Diospyros kaki) as affected by various fruit-loads. The effects of such changes were monitored with regard to the abundance of new growth in the following year. On June 15, the fruit-load was adjusted to a leaf–fruit (L/F) ratio of 10, 20, and 30, and some trees were completely defruited. Between June 15 and November 11, the increase in DW was less in the defruited and more in the higher L/F-ratio trees. Among the various tree parts, the DW increased the most in the fruits during the same period. It was observed that the lower the L/F ratio, the more the DW in the fruits: the fruits accounted for 78.7% of the total DW in the 10-L/F, 57.6% in the 20-L/F, and 49.7% in the 30-L/F ratio trees. In contrast, as the L/F ratio increased, the DW distribution to the roots increased to 3% in the 10-L/F, 13% in the 20-L/F, and 26% in the 30-L/F ratio trees and 61% in the defruited trees. During this period, carbohydrates were distributed mostly to the fruits, but as the L/F ratio decreased, their distribution to permanent tree parts decreased. The distribution of soluble sugars and starch to the permanent parts was 1% and 14% in the 10-L/F, 3% and 48% in the 20-L/F, 9% and 57% in the 30-L/F ratio trees, and 71% and 93% in the defruited trees, respectively. Maintaining a lower L/F ratio resulted in a decrease in the shoot and fruit numbers in the following year: there were zero and four fruits in those trees with an L/F ratio of 10 and 20, respectively. The carbohydrates decreased in the roots of both the 30-L/F ratio trees and the defruited trees, whereas the defruited trees showed more new shoot growth in the following year. In the roots of the trees with the L/F ratio of 30, soluble sugars and starch decreased by 7.6 g and 1.8 g, respectively, during the spring growth, whereas, in the roots of the defruited trees soluble sugars and starch decreased by 33.3 g and 94.6 g, respectively.  相似文献   

Mucosa-associated lymphoid tissue lymphoma of the third eyelid conjunctiva in a dog     

Hong IH  Bae SH  Lee SG  Park JK  Ji AR  Ki MR  Han SY  Lee EM  Kim AY  You SY  Kim TH  Jeong KS 《Veterinary ophthalmology》2011,14(1):61-65

A 4-year-old, neutered female Cocker Spaniel was presented to the veterinary clinic for protrusion of the left third eyelid. When the third eyelids from both eyes were everted, lobulated masses were present on the bulbar surface. The left third eyelid had a larger protrusion. There was no apparent associated ocular or systemic involvement. The tumor of left third eyelid was removed and referred for histological examination. Histologically, there were proliferations of lymphoid follicles surrounded by lymphoid cells forming a marginal zone. Those lymphoid cells occasionally infiltrated into conjunctival epithelium. A few apoptotic bodies with karyopyknotic and karyorrhexic nuclei were observed in the germinal center of lymphoid follicles. Mitotic figures were rare. On immunohistochemistry, tumor cells expressed CD79a but not CD3. A diagnosis of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the third eyelid was established based on the histological and immunophenotypical features. At the 1-year follow-up, there was no evidence of recurrence of the mass at the area of excision of the left third eyelid and the remaining tumor of the right third eyelid was still a similar size. The dog still showed no significant findings, except those of the tumor, and no evidence of systemic involvement. To the authors' knowledge, this is the first reported case of MALT lymphoma of the third eyelid in a dog.  相似文献   

Loss of pendimethalin in runoff and leaching from turfgrass land under simulated rainfall   总被引：2，自引：0，他引：2  

Lee YD  Kim HJ  Chung JB  Jeong BR 《Journal of agricultural and food chemistry》2000,48(11):5376-5382

A field study was undertaken to investigate runoff and leaching loss of the herbicide pendimethalin in turfgrass land of loamy sand soil. A series of plots constructed in a golf course fairway were surface-applied with pendimethalin SC formulation at the rate of 2. 25 or 4.50 kg a.i./ha and subjected to simulated rainfall at 2.0 cm/day for 10 consecutive days. Runoff losses of pendimethalin were the highest at the first rainfall and then gradually decreased with time. The first runoff event contained pendimethalin in its highest concentration, and in subsequent runoff samples the concentration decreased exponentially. The ranges of pendimethalin concentration were 80.9-18.2 and 177.4-48.6 microgram/L in the standard and double doses, respectively. Total losses by 20 cm of rainfall for 10 days reached 0.81 and 1.22% of the initial deposits at 2.25 and 4.50 kg a. i./ha, respectively. Pendimethalin concentration in the leachate collected at 30-cm soil depth was quite lower than that in the runoff, and the concentration rapidly decreased from 4.3-4.7 to 0. 2-0.4 microgram/L during the 10 days of rainfall treatment. Soil residue analysis at 45 and 90 days after pendimethalin treatment showed that more than 90% of the residue remained at the top 10 cm of soil depth. Low runoff and leaching confirmed that lateral and downward movement of the herbicide should be limited in turf soil. The half-life of pendimethalin under field conditions was 23-30 days and was not affected by application dose and rainfall treatment, but longer persistence was observed under laboratory conditions. Considering low runoff and leaching, as well as relatively short persistence in soil, it is concluded that little environmental carryover of pendimethalin would be expected in turfgrass land.  相似文献   

Methylation methods for the quantitative analysis of conjugated linoleic acid (CLA) isomers in various lipid samples   总被引：8，自引：0，他引：8  

Park SJ  Park CW  Kim SJ  Kim JK  Kim YR  Park KA  Kim JO  Ha YL 《Journal of agricultural and food chemistry》2002,50(5):989-996

Precise methylation methods for various chemical forms of conjugated linoleic acid (CLA), which minimize the formation of t,t isomers and allylmethoxy derivatives (AMD) with the completion of methylation, were developed using a 50 mg lipid sample, 3 mL of 1.0 N H(2)SO(4)/methanol, and/or 3 mL of 20% tetramethylguanidine (TMG)/methanol solution(s). Free CLA (FCLA) was methylated with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). CLA esterified in safflower oil (CLA-SO) was methylated with 20% TMG/methanol (100 degrees C, 5 min), whereas CLA esterified in phospholipid (CLA-PL) was methylated with 20% TMG/methanol (100 degrees C, 10 min), followed by an additional reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). Similarly, CLA esterified in egg yolk lipid (CLA-EYL) was methylated by base hydrolysis, followed by reaction with 1.0 N H(2)SO(4)/methanol (55 degrees C, 5 min). These results suggest that for the quantitative analysis of CLA in lipid samples by GC, proper methylation methods should be chosen on the basis of the chemical forms of CLA in samples.  相似文献   

Polyozellin isolated from Polyozellus multiplex induces phase 2 enzymes in mouse hepatoma cells and differentiation in human myeloid leukaemic cell lines     

Kim JH  Lee JS  Song KS  Kwon CS  Kim YK  Kim JS 《Journal of agricultural and food chemistry》2004,52(3):451-455

Induction of cellular phase 2 detoxifying enzymes is associated with cancer preventive potential. Quinone reductase (QR) has been used as a prototype for anticarcinogenic phase 2 enzymes because of its widespread distribution in mammalian systems, large amplitude of inducer response, and ease of measurement in murine hepatoma cells. Methanol extract of Polyozellus multiplex, which shows a strong QR induction potential, was subjected to bioassay-guided fractionation, and polyozellin (PM1) appeared to be a major active component. In in vitro cultured cells (hepa1c1c7 and BPRc1 cells), polyozellin enhanced QR, glutathione S-transferase (GST) activities, and glutathione (GSH) content in a dose-dependent manner. The compound also significantly promoted differentiation of HL-60 human promyelocytic emia cells. In conclusion, polyozellin deserves further in vivo study to evaluate its potential as a cancer preventive agent.  相似文献   

Outbreaks of classical swine fever in the Republic of Korea in 2003     

Wee SH  Park CK  Jeong JM  Kim CH  Hwang IJ  Kim SJ  Yoon H  Lee ES  Nam HM  Park JY  Moon OK 《The Veterinary record》2005,157(4):113-115

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