Flavonoids are secondary metabolites involved in several aspects of plant development and defence. They colour fruits and flowers, favouring seed and pollen dispersal, and contribute to plant adaptation to environmental conditions such as cold or UV stresses, and pathogen attacks. Because they affect the quality of flowers (for horticulture), fruits and vegetables, and their derivatives (colour, aroma, stringency, etc.), flavonoids have a high economic value. Furthermore, these compounds possess pharmaceutical properties extremely attractive for human health. Thanks to easily detectable mutant phenotypes, such as modification of petal pigmentation and seeds exhibiting transparent testa, the enzymes involved in the flavonoid biosynthetic pathway have been characterized in several plant species. Conserved features as well as specific differences have been described. Regulation of structural gene expression appears tightly organized in a spatial and temporal way during plant development, and is orchestrated by a ternary complex involving transcription factors from the R2R3-MYB, basic helix-loop-helix (bHLH), and WD40 classes. This MYB-bHLH-WD40 (MBW) complex regulates the genes that encode enzymes specifically involved in the late steps of the pathway leading to the biosynthesis of anthocyanins and condensed tannins. Although several genes encoding transcription factors from these three families have been identified, many gaps remain in our understanding of the regulation of this biosynthetic pathway, especially about the respective roles of bHLH and WD40 proteins. A better knowledge of the regulatory mechanisms of the flavonoid pathway is likely to favour the development of new biotechnological tools for the generation of value-added plants with optimized flavonoid content.

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Recent advances in the transcriptional regulation of the flavonoid biosynthetic pathway

Regulation of gene expression at the level of transcription controls many crucial biological processes. Transcription factors (TFs) play a great role in controlling cellular processes and MYB TF family is large and involved in controlling various processes like responses to biotic and abiotic stresses, development, differentiation, metabolism, defense etc. Here, we review MYB TFs with particular emphasis on their role in controlling different biological processes. This will provide valuable insights in understanding regulatory networks and associated functions to develop strategies for crop improvement.

/pdf/myb-transcription-factor-genes-as-regulators-for-plant-1xuf8cbdfx.pdf

MYB transcription factor genes as regulators for plant responses: an overview

Development and biological activities of marine-derived bioactive peptides: A review

Turmeric is traditionally used as a spice and coloring in foods. It is an important ingredient in curry and gives curry powder its characteristic yellow color. As a consequence of its intense yellow color, turmeric, or curcumin (food additive E100), is used as a food coloring (e.g. mustard). Turmeric contains the curcuminoids curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Recently, the health properties (neuroprotection, chemo-, and cancer prevention) of curcuminoids have gained increasing attention. Curcuminoids induce endogenous antioxidant defense mechanisms in the organism and have anti-inflammatory activity. Curcuminoids influence gene expression as well as epigenetic mechanisms. Synthetic curcumin analogues also exhibit biological activity. This Review describes the development of curcumin from a "traditional" spice and food coloring to a "modern" biological regulator.

Curcumin—From Molecule to Biological Function

https://repositorium.sdum.uminho.pt/bitstream/1822/16854/1/3587.pdf

Bioactive phenolic compounds : production and extraction by solid-state fermentation. A review

Near infrared spectroscopy (NIRS) is a rapid and accurate analytical method for determining the composition of agricultural products and feeds. The applicability of near infrared reflectance spectroscopic method was tested to determine the color value (L, a, b) of green tea. A total of 162 green tea calibration samples and 82 validation samples were used for NIRS equation development and validation, respectively. In the developed NIRS equation for analysis of the color value (L, a, b), the most accurate equation for L value was obtained at 2, 8, 6, 1 (2nd derivative, 8 nm gap, 6 points smoothing, and 1pointsecond smoothing), and for a, and b value were obtained at 1, 4, 4, 1 (1st derivative, 4 nm gap, 4points smoothing, and 1 point second smoothing) math treatment condition with SNVD (Standard Normal Variate and Detrend) scatter correction method and entire spectrum (400~2,500~;nm ) by using MPLS (Modified Partial Least Squares) regression. Validation results of these NIRS equations showed very low bias (L: 0.005%, a: 0.003%, b: -0.013%) and standard error of prediction (SEP, L: 0.361%, a: 0.141%, b: 0.306%) as well as high coefficient of determination (R2 , L: 0.905, a: 0.986, b: 0.931). Therefore, these NIRS equations can be applicable and reliable for determination of color value (L, a, b) of green tea, and NIRS method could be used as a mass screening technique for breeding programs and quality control in the green tea industry.

근적외 분광분석법을 이용한 녹차의 색도 분석

Quintozene, pentachloronitrobenzene (PCNB) is a contact fungicide for control of soilbornephytopathogenic fungi during cultivation of diverse crops. It was introduced to agricultural use around 1930’sas a substitute for mercurial disinfectants. Although quintozene had been first registered in Korea on 1969.However, now it was banned to use due to its high residue levels in selected harvest products. Also, highpossibility is expected that the residue may be contained in imported agricultural commodities as it is stillused widely over the world. Therefore, this study was conducted to establish a determination method forquintozene residue in crops using GC/ECD/MS. Quintozene residue was extracted with acetonitrile fromrepresentative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, greenpepper, and apple. The extract was diluted with saline water, and n-hexane partition was followed to recoverquintozene from the aqueous phase. Florisil column chromatography was additionally employed for finalclean up of the extract. The quintozene was quantitated by GLC with ECD, using a DB-1 capillary column.The crops were fortified with quintozene at 3 levels per crop. Mean recoveries ranged from 79.9% to 102.7%in five representative agricultural commodities. The coefficients of variation were less than 4.3%. Quantitativelimit of quintozene was 0.004 mg/kg in representative five crop samples. A GC/MS with selected-ionmonitoring was also provided to confirm the suspected residue. Therefore, this analytical method wasreproducible and sensitive enough to determine the residue of quintozene in agricultural commodities.Key words GC-ECD/MS, Quintozene, Residue

Determination of Quintozene Residues in Agricultural Commodities Using GC-ECD/MS

Establishment of Pre-Harvest Residue Limit(PHRL) of the Fungicide Amisulbrom during Cultivation of Winter-Grown Cabbage Kyung-Geun Ahn, Gyeong-Ha Kim, Gi-Ppeum Kim, Min-Ji Kim, Seung-Beom Hong, Young-Sun Hwang, Chan-Hyeok Kwon, Young Wook Son, Young Deuk Lee and Myoung-Gun Choung* (Department of Herbal Medicine Resource, Kangwon National University, Samcheok, 245-711, Korea, Department of Biology, University of Texas-Arlington, Arlington, TX 76019, USA, Food Standard Division, Ministry of Food and Drug Safety, Cheongju, 363-700, Korea, Division of Life and Environmental Science, Daegu University, Gyeongsan, 712-714, Korea)

/pdf/establishment-of-pre-harvest-residue-limit-phrl-of-the-4itzo2wh0u.pdf

Establishment of Pre-Harvest Residue Limit(PHRL) of the Fungicide Amisulbrom during Cultivation of Winter-Grown Cabbage

Analytical Method for Flusulfamide as Benzenesulfonamide Fungicide, Residues in Major Agricultural Commodities Kyung-Geun Ahn, Gi-Ppeum Kim, Young-Sun Hwang, In-Kyu Kang, Young Deuk Lee and Myoung-Gun Choung (Department of Herbal Medicine Resource, Kangwon National University, Samcheok 25949, Korea, Department of Biology, University of Texas-Arlington, Arlington, TX 76019, USA, Department of Horticultural Science, Kyungpook National University, Daegu 41566, Korea, Division of Life and Environmental Science, Daegu University, Gyeongsan 38453, Korea)

/pdf/analytical-method-for-flusulfamide-as-benzenesulfonamide-578egpmpnl.pdf

Myoung-Gun Choung

Papers

근적외 분광분석법을 이용한 녹차의 색도 분석

Determination of Quintozene Residues in Agricultural Commodities Using GC-ECD/MS

Establishment of Pre-Harvest Residue Limit(PHRL) of the Fungicide Amisulbrom during Cultivation of Winter-Grown Cabbage

Analytical Method for Flusulfamide as Benzenesulfonamide Fungicide, Residues in Major Agricultural Commodities

Sugar and Isoflavone Contents of Traditional Korean Soybean Fermented Foods