115 research outputs found

    Redirecting an Anticancer to an Antibacterial Hit Against Methicillin-Resistant Staphylococcus aureus

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    YM155 is a clinically evaluated anticancer with a fused naphthoquinone-imidazolium scaffold. In this study, we demonstrated that based on weak or cryptic antibacterial activity of YM155 against methicillin-resistant Staphylococcus aureus (MRSA) (MIC of 50 Ī¼g/ml), some congeneric compounds with short alkyl chains (e.g., c5 with a hexyl chain) at the N3 position of the scaffold, displayed more potent antibacterial activity against MRSA (MIC of 3.13 Ī¼g/ml), which is in a clinically achievable range. Their antibacterial activity was evident against Gram-negative bacteria, only in the presence of the outer membrane-permeabilizing agent, polymyxin B. The antibacterial efficacy of c5 was confirmed using the Drosophila systemic infection model. We also characterized five spontaneous c5-resistant MRSA mutants that carry mutations in the ubiE gene, for quinone metabolism and respiratory electron transfer, and subsequently exhibited reduced respiration activity. The antibacterial activity of c5 was compromised either by an antioxidant, N-acetylcysteine, or in an anaerobic condition. These suggest that the antibacterial mechanism of c5 involves the generation of reactive oxygen species (ROS), presumably during respiratory electron transport. This study provides an insight into ā€œdrug redirecting,ā€ through a chemical modification, based on an ROS-generating pharmacophore

    Autophagy pathway upregulation in a human iPSC-derived neuronal model of Cohen syndrome with VPS13B missense mutations

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    Significant clinical symptoms of Cohen syndrome (CS), a rare autosomal recessive disorder, include intellectual disability, facial dysmorphism, postnatal microcephaly, retinal dystrophy, and intermittent neutropenia. CS has been associated with mutations in the VPS13B (vacuolar protein sorting 13 homolog B) gene, which regulates vesicle-mediated protein sorting and transport; however, the cellular mechanism underlying CS pathogenesis in patient-derived neurons remains uncertain. This report states that autophagic vacuoles accumulate in CS fibroblasts and the axonal terminals of CS patient-specific induced pluripotent stem cells (CS iPSC)-derived neurons; additionally, autophagic flux was significantly increased in CS-derived neurons compared to control neurons. VPS13B knockout HeLa cell lines generated using the CRISPR/Cas9 genome editing system showed significant upregulation of autophagic flux, indicating that VSP13B may be associated with autophagy in CS. Transcriptomic analysis focusing on the autophagy pathway revealed that genes associated with autophagosome organization were dysregulated in CS-derived neurons. ATG4C is a mammalian ATG4 paralog and a crucial regulatory component of the autophagosome biogenesis/recycling pathway. ATG4C was significantly upregulated in CS-derived neurons, indicating that autophagy is upregulated in CS neurons. The autophagy pathway in CS neurons may be associated with the pathophysiology exhibited in the neural network of CS patients.This work was supported by National Research Foundation (NRF2017R1D1A3B03030972), the National Honor Scientist Program, the Korea Health Technology R&D Project (HI18C0158), and the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science & ICT (2017M3A9G7073521) to J.-A L

    Trends of Gastrointestinal Diseases at a Single Institution in Korea over the Past Two Decades

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    The Different Contributors to Antioxidant Activity in Thermally Dried Flesh and Peel of Astringent Persimmon Fruit

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    In the thermal-drying processing of astringent persimmon fruit, the tissue-specific changes in the key antioxidants have hardly been investigated, while they have been well investigated in the flesh. We report here the different patterns of the antioxidant activities in the thermally processed flesh and peel of astringent persimmon, with analyses of the carotenoids, the condensed and hydrolysable tannins, and the total phenolics and flavonoids. The persimmon powders presented different colors on the basis of the drying temperatures: brown in 30 °C; light yellow in 60 °C; and dark brown in 90 °C, respectively. Non-maillard reaction and reduction of carotenoids caused the light-yellow color of 60 °C dried persimmon. Thermal drying reduced the antioxidant activities of the flesh in a temperature-dependent manner, with decreases in the carotenoids, the condensed and hydrolysable tannins, and the total phenolics and flavonoids, whereas it enhanced the antioxidant activities of the peel. The increase in the antioxidant activities in the peel were mainly the result of the increase in the total phenolics by the thermal effect, and especially in the content of the hydrolysable tannins, although the thermal processing decreased the other components. The heat-induced increase of antioxidant activity in the peel showed a strong significant correlation only with the contents of total phenolics (r2 = 0.9493) and total hydrolysable tannins (r2 = 0.9288), suggesting that the main antioxidant contributors differ from the flesh

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    Summary Chapter 1 Introduction 1. Introduction: Korean Government Efforts to Keep the Country Drug-Free 2. Change in the Environment and Threat Factor Chapter 2 Criminal Proceeds Confiscation System for Restriction of Narcotics Offenders 1. Background of the Legislation 2. Introduction of Criminal Proceeds Confiscation System 3. Meaning of Criminal Proceeds Confiscation System Chapter 3 Introduction and Operation Trends of Criminal Proceeds Confiscation System of Various Countries 1. Criminal Proceeds Confiscation System of Various Countries 2. Comparison of Criminal Proceeds Confiscation and Collection System of Various Countries Chapter 4 Enactment and Operation Status of 怌Act on Special Cases Concerning the Confiscations of Criminal怍 Proceeds 1. Enactment of the 怌Act on Special Cases Concerning the Prevention of Illegal Trafficking in Narcotics, etc.怍 2. Granting of Duty of Cooperation on Financial Institutions 3. Construction of Pan-National Narcotic Crime Response System 4. Creation of the Organization in Charge of Confiscation of Crime Profit Chapter 5 Factors for Successful Confiscation and Collection ā€“ Main Examples 1. Factors for Successful Confiscation and Collection 2. Confiscation and Collection of Proceeds from Smuggling and Trafficking of Methamphetamine [Case 1] 3. Large-Scale Arrest of Drug Substitute Traffickers [Case 2] 4. Confiscation of Illegal Profit and Property of Drug Crime [Case 3] 5. Confiscation and Collection of Methamphetamine Sales Profit [Case 4] 6. Problem and Improvement Plan for Deprivation of Narcotics Fund 7. Analysis of Performance of Criminal Proceeds Confiscation System in Korea Chapter 6 Suggestion for Establishment of Policy for Developing Countries 1. Active Securing of Means of Investigation 2. Alert of Investigation Expediency 3. Securing Professional Investigation Personnel and Fund Tracing Education 4. Relaxation of Saving Confidentiality Principle 5. Expansion of Obligation of Financial Institutions 6. Expansion of Role of Korea Financial Intelligence Unit (FIU) 7. Close Cooperative Investigation and Cooperation Relation References Appendice

    Changes in Quercetin Derivatives and Antioxidant Activity in Marigold Petals (Tagetes patula L.) Induced by Ultraviolet-B Irradiation and Methyl Jasmonate

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    Marigold petals contain numerous antioxidative flavonoids and carotenoids that can be affected by environmental stressors. There is yet no detailed study on the relationship between phytochemical accumulation and stressors in marigold petals. This study evaluated quercetin derivatives and antioxidant activity in marigold petals in response to ultraviolet-B (UV-B) irradiation and methyl jasmonate (MeJA) treatment. The limiting UV-B radiation intensity and MeJA dose that caused no wilting damage under 1-h daily treatment for 10 days were <2 W∙m−2∙s−1 and <10 mM, respectively. Marigold petals contained three major flavonoids, quercetin-7-O-glucoside (Q7G, 6.6 mg∙g−1dw), quercetin-3-O-glucoside (Q3G, 62.7 mg), and quercetin (26.6 mg), possessing different antioxidant potential and exhibiting the highest power in quercetin and next value in Q7G. Single UV-B irradiation exerted a limited effect on the changes in the content of the three quercetin derivatives, whereas combined treatment with 1 W UV-B radiation and 5 mM MeJA resulted in the highest total quercetin content, showing >20% increase compared to that without treatment. This increase primarily resulted in an increase in quercetin content. MeJA treatment positively affected the increase in Q3G and Q7G contents in a dose-dependent manner during the 10-d experimental period but exerted no considerable effect on quercetin accumulation. The antioxidant activity was increased when flowers were exposed to mild MeJA treatment of 5–10 mM. UV-B irradiation decreased the antioxidant activity of marigold petals, but this decrease could be compensated by MeJA treatment

    Impact of Dry Processing on Secondary Metabolites in the Petals of Marigold (<i>Tagetes</i> spp.) Cultivar

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    The edible flowers of marigold (Tagetes spp.) are cultivated for their aesthetic appeal and high utility as functional health food ingredients. Carotenoid and flavonoid contents in marigold petals highlight the importance of selecting the appropriate cultivar and its processing methods for their industrial applications. The comparative understanding of the effects of dry processing on functional components across different marigold cultivars is still lacking. Therefore, this study investigated functional compound changes in the dry processing effect on four marigold cultivars with distinct flower shapes (Durango, Inca) and colors (yellow, orange). The petals in hot air drying (HAD) with 30, 60, and 90 Ā°C applications were analyzed for the measurement of their individual secondary metabolite contents, total phenolic and flavonoid contents, and antioxidant activities. In freeze drying (FD), the lutein content varied significantly based on flower color, exhibiting higher levels in cultivars with orange petals. Otherwise, the levels of quercetin derivatives displayed distinct differences based on varieties other than color, with Inca cultivars demonstrating higher levels of quercetin 7-O-glucoside (Q7G) than Durango cultivars. In HAD, the lutein levels show a tendency to increase above 60 Ā°C regardless of the cultivar. The content of quercetin glycosides decreased, while the aglycone increased in HAD treatments, regardless of the temperatures. Correlation and PCA results highlighted the impact of phenol compounds on antioxidant activity. Overall, these findings underscore the significance of variety and color in determining the chemical composition and antioxidant properties of marigold flowers
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