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Cho J.-Y.,Chonnam National University | Lee H.J.,Chonnam National University | Kim G.A.,Chonnam National University | Kim G.D.,Chonnam National University | And 4 more authors.
Journal of Cereal Science | Year: 2012

γ-Oryzanol (steryl ferulates; SF) has been shown to be a major bioactive compound in rice. To determine the content of individual γ-oryzanols in brown rice by high performance liquid chromatography (HPLC), purification of individual SF for use as an external standard is required. Four main SF were isolated from a commercial γ-oryzanol mixture and identified as cycloartenyl ferulate (1), 24-methylenecycloartanyl ferulate (2), campesteryl ferulate (3), and sitosteryl ferulate (4) based on mass spectrometry and nuclear magnetic resonance spectroscopic data. The SF contents between conventional and organic brown rice were qualitatively determined by HPLC using SF isolated from a commercial γ-oryzanol mixture as the external standard. The total γ-oryzanol content (mg/100 g) in organic brown rice (65.6 ± 2.7) was slightly higher (P < 0.05) than that found in conventional brown rice (60.2 ± 1.8). The content (mg/100 g) of 1 (21.2 ± 0.9) and 4 (9.8 ± 0.4) in organic brown rice was higher (P < 0.05) than that observed in conventional brown rice (1, 18.2 ± 1.1; 4, 8.5 ± 0.3). However, the content of 2 and 3 in the conventional and organic brown rice samples did not differ significantly. These results indicate that the cultivation methods do significantly alter the γ-oryzanol content for conventional and organic brown rice. © 2012 Elsevier Ltd. Source

Kim S.-H.,Chonnam National University | Yoo S.-J.,Chonnam National University | Min K.-H.,Chonnam National University | Nam S.-H.,Jeonnam Agricultural Research and Extension Services | And 2 more authors.
Biochemical and Biophysical Research Communications | Year: 2013

Polyamines in plants are involved in various physiological and developmental processes including abiotic and biotic stress responses. We investigated the expression of ADCs, which are key enzymes in putrescine (Put) biosynthesis, and roles of Put involving defense response in Arabidopsis. The increased expression of ADC1 and ADC2, and the induction of Put were detected in GVG-NtMEK2DD transgenic Arabidopsis, whereas, their performance was partially compromised in GVG-NtMEK2DD/mpk3 and GVG-NtMEK2DD/mpk6 mutant following DEX treatment. The expression of ADC2 was highly induced by Pst DC3000 inoculation, while the transcript levels of ADC1 were slightly up-regulated. Compared to the WT plant, Put content in the adc2 knock-out mutant was reduced after Pst DC3000 inoculation, and showed enhanced susceptibility to pathogen infection. The adc2 mutant exhibited reduced expression of PR-1 after bacterial infection and the growth of the pathogen was about 4-fold more than that in the WT plant. Furthermore, the disease susceptibility of the adc2 mutant was recovered by the addition of exogenous Put. Taken together, these results suggest that Arabidopsis MPK3 and MPK6 play a positive role in the regulation of Put biosynthesis, and that Put contributes to bacterial pathogen defense in Arabidopsis. © 2013 Elsevier Inc. Source

Kim D.-K.,Jeonnam Agricultural Research and Extension Services | Jeong S.C.,Sunchon National University | Gorinstein S.,Hebrew University of Jerusalem | Chon S.-U.,Chosun University
Plant Foods for Human Nutrition | Year: 2012

The aim of this investigation was to evaluate the biological, alcohol dehydrogenase (ADH) and antiproliferative activities of different extracts of mungbean seeds and sprouts. All extracts from the sprouts showed higher contents of total phenolics (TP), total flavonoids (TF), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than from seeds. The highest DPPH and tyrosinase inhibition activities were registered in ethyl acetate (EtOAc) extract. ADH activity of methanol (MeOH), n-hexane (n-hexane) and n-butanol (n-BuOH) extracts from sprouts was significantly higher (P < 0. 05) than from seeds. However, the highest ADH activity was found in water extract of seeds. According to 3-(4, 5-dimethylthiazol -2-yl)-2, 5-diphenyltetrazolium bromide) (MTT) assay, extracts from sprouts were more effective against Calu-6 (human pulmonary carcinoma) and SNU-601 (human gastric carcinoma) cells than from seeds. EtOAc extract showed the highest antiproliferative activity in both sprouts and seeds, followed by n-hexane extraction. During sprouting of mungbean, all the studied components significantly increased. In conclusion, the extracts of sprouts are more effective than from seeds and could be a potential source of antioxidants linked with health benefits. © 2012 Springer Science+Business Media, Inc. Source

Nguyen T.T.H.,Chonnam National University | Moon Y.-H.,Audubon Sugar Institute | Ryu Y.-B.,Korea Research Institute of Bioscience and Biotechnology | Kim Y.-M.,Korea Research Institute of Bioscience and Biotechnology | And 4 more authors.
Enzyme and Microbial Technology | Year: 2013

The human fibroblast collagenase catalytic domain (MMP1ca) that is considered a prototype for all interstitial collagenase and plays an important role in the turnover of collagen fibrils in the matrix was expressed as an inclusion body in the Escherichia coli. The purified enzyme displayed activity with substrate Dnp-Pro-Leu-Ala-Leu-Trp-Ala-Arg-OH with a Km value of 26.61±1.42μM. The inhibition activity of the nine flavonoid compounds and gallic acid against MMP1ca was examined. Among the compounds tested, the IC50 of seven flavonoid compounds were determined and ranged from 14.13 to 339.21μM. Epigallocatechin gallate (EGCG) showed the highest inhibition toward MMP1ca with IC50 values of 14.13±0.49μM. EGCG showed a competitive inhibition pattern with a Ki value of 10.47±0.51μM. The free binding energy of EGCG against MMP1ca was -13.07kcalmol-1, which was calculated by using Autodock 3.0.5 software and showed numerous hydrophobic and hydrogen bond interactions. The galloyl group of EGCG, gallocatechin gallate and epicatechin gallate was determined to be important for inhibitory activity against MMP1ca. © 2012 Elsevier Inc. Source

Lee J.,National Academy of Agricultural Science | Park K.W.,Chungnam National University | Lee I.-Y.,National Academy of Agricultural Science | Kim C.-S.,National Academy of Agricultural Science | And 2 more authors.
Weed Research | Year: 2015

Echinochloa species are amongst the most problematic weeds in rice fields of Korea. The steady reliance on the Acetyl-CoA carboxylase (ACCase) and acetolactate synthase inhibiting herbicides for control of these weeds has led to resistance to these herbicides. The objective of this study was to assess the genetic diversity among populations of ACCase inhibitor-resistant and -susceptible Echinochloa crus-galli and E. oryzicola in Korea, to better understand their population structure and possible origins of resistance. Seven simple sequence repeat markers were applied to assess the genetic diversity between resistant and susceptible E. crus-galli and E. oryzicola from 12 populations in Korea. Genetic diversity was slightly higher in the resistant group. The Unweighted Pair Group Method using Arithmetic algorithm (UPGMA) dendrogram generated two distinct clades. One clade consisted of Echinochloa spp. from three populations, i.e. Anmyeondo, Gimje 4 and Gongju, which are resistant and differentiated from the susceptible populations, and the other clade contained the rest of the populations. Structure modelling supported two clades of UPGMA clustering. Based on these data, we can infer that some resistant populations are greatly differentiated, whereas other resistant biotypes are still building up resistance in rice fields in Korea. Resistance traits will be fixed and continue to spread over time without proper control measures. Weed Research © 2015 European Weed Research Society. Source

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