Publications by authors named "Yeong-Hun Song"

Background: Assessing tau accumulation in early affected areas like the lateral entorhinal cortex (EC) and inferior temporal gyrus (ITG) enables early prediction of disease progression and cognitive decline. However, positron emission tomography (PET) imaging poses radiation exposure and cost concerns. This research aims to develop a deep learning model predicting tau positivity in these regions using MRI.

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Background: Brain connectivity is useful for deciphering complex brain dynamics controlling interregional communication. Identifying specific brain phenomena based on brain connectivity and quantifying their levels can help explain or diagnose neurodegenerative disorders.

Objective: This study aimed to establish a unified framework to identify brain connectivity-based biomarkers associated with disease progression and summarize them into a single numerical value, with consideration for connectivity-specific structural attributes.

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Structural changes in the brain due to Alzheimer's disease dementia (ADD) can be observed through brain T1-weighted magnetic resonance imaging (MRI) images. Many ADD diagnostic studies using brain MRI images have been conducted with machine-learning and deep-learning models. Although reliability is a key in clinical application and applicability of low-resolution MRI (LRMRI) is a key to broad clinical application, both are not sufficiently studied in the deep-learning area.

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Citrus fruits undergo significant metabolic profile changes during their development process. However, limited information is available on the changes in the metabolites of during fruit development. Here, we analyzed the total phenolic content (TPC), total carotenoid content (TCC), antioxidant activity, and metabolite profiles in fruit flesh during different stages of fruit development and evaluated their correlations.

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is a genus of plants containing multiple species with well-documented medicinal effects. and are among the best-studied species, and previous works have established flavones to be the primary source of their bioactivity. Recent genomic and biochemical studies with and have advanced our understanding of flavone biosynthesis in .

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In this study, the changes in free amino acids of soybean leaves after ethylene application were characterized based on quantitative and metabolomic analyses. All essential and nonessential amino acids in soybean leaves were enhanced by fivefold (250 to 1284 mg/100 g) and sixfold (544 to 3478 mg/100 g), respectively, via ethylene application. In particular, it was found that asparagine is the main component, comprising approximately 41% of the total amino acids with a twenty-five fold increase (78 to 1971 mg/100 g).

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Plants produce diverse secondary metabolites. Although each metabolite is made through its respective biosynthetic pathway, plants coordinate multiple biosynthetic pathways simultaneously. One example is an interaction between glucosinolate and phenylpropanoid pathways in .

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The chromenone derivatives (1-4) from the root part of Flemingia philippinensis showed a significant inhibition against bacterial neuraminidase (NA) which plays a pivotal role in a cellular interaction including pathogenesis of bacterial infection and subsequent inflammation. The compounds 1 and 2 were the new compounds, philippin D (1) and philippin E (2). In particular, compounds (1-3) exhibited sub micromolar levels of IC values with 0.

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Pectin methylesterases (PMEs) catalyze pectin demethylation and facilitate the determination of the degree of methyl esterification of cell wall in higher plants. The regulation of PME activity through endogenous proteinaceous PME inhibitors (PMEIs) alters the status of pectin methylation and influences plant growth and development. In this study, we performed a PMEI screening assay using a chemical library and identified a strong inhibitor, phenylephrine (PE).

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This research was the first to demonstrate changes in nutritional compositions (isoflavone and CLA) from the 50% methanol extracts of soy-powder milk (SPM) and soy-powder yogurt (SPY) through fermentation using Lactobacillus plantarum S48 and P1201 strains. The radical scavenging activities and protective effects against oxidative stress in LLC-PK cells were also investigated. The average physicochemical characteristics including acidity and viable cell number as well as β-glucosidase activity increased with 0.

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s Merr. et Rolfe has been cultivated on a large scale and is widely consumed by local inhabitants as an important nutraceutical, especially against rheumatism which has a deep connection with antioxidants. In this study, a total of 18 different phenolic metabolite compounds in s were isolated and identified, and evaluated for their antioxidant and DNA damage protection potential.

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Flemingia philippinensis has been used throughout history to cure rheumatism associated with neutrophil elastase (NE). In this study, we isolated sixteen NE inhibitory flavonoids (1-16), including the most potent and abundant prenyl isoflavones (1-9), from the F. philippinensis plant.

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Diabetes mellitus is one of a major worldwide concerns, regulated by either defects in secretion or action of insulin, or both. Insulin signaling down-regulation has been related with over activity of protein tyrosine phosphatase 1B (PTP1B) enzyme, which has been a promising target for the treatment of diabetes mellitus. Herein, activity guided separation of methanol extract (95%) of aerial parts afforded nine (-) polyphenolic compounds, all of them were identified through spectroscopic data including 2D NMR and HREIMS.

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Four new caged xanthones (1-4) and two known compounds (5, 6) were isolated from the roots of Cratoxylum cochinchinense, a polyphenol rich plant, collected in China. The structures of the isolated compounds (1-6) were characterized by obtaining their detailed spectroscopic data. In particular, compounds 1 and 6 were fully identified by X-ray crystallographic data.

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Cratoxylum cochinchinense displayed significant inhibition against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase, both of which are key target enzymes to attenuate diabetes and obesity. The compounds responsible for both enzymes inhibition were identified as twelve xanthones (1-12) among which compounds 1 and 2 were found to be new ones. All of them simultaneously inhibited PTP1B with ICs of (2.

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Protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase are important targets to treat obesity and diabetes, due to their deep correlation with insulin and leptin signalling, and glucose regulation. The methanol extract of Paulownia tomentosa fruits showed potent inhibition against both enzymes. Purification of this extract led to eight geranylated flavonoids (1-8) displaying dual inhibition of PTP1B and α-glucosidase.

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Members of the genus Limonium are widely used as medicinal herbs due to their health-promoting effects, such as an ability to improve blood circulation by inhibiting angiotensin I converting enzyme (ACE). While the potential of L. michelsonii Lincz.

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Protein tyrosine phosphatase 1B (PTP1B) plays important role in diabetes, obesity and cancer. The methanol extract of the gum resin of Garcinia hanburyi (G. hanburyi) showed potent PTP1B inhibition at 10µg/ml.

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Dietary isoflavones, daidzein and genistein are of huge interest in the nutraceutical field due to their practical application to postmenopause complications. This study is the first report an efficient method to prepare isoflavone rich soybean leaves (soyleaves) which is an edible food stuff in Asian countries. The preharvest treatment of ethylene highly stimulated the level of isoflavone in soyleaves.

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Campylotropis hirtella is used as a food supplement in the subtropical region of China. In an intensive hunt for human neutrophil elastase inhibitors, we isolated eight flavonoids from C. hirtella three of which (1-3) emerged to be elastase inhibitors.

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Ethnopharmacological Relevance: P. cuspidatum is a popular Chinese medicinal herb, having a long history of usage in traditional Chinese medicine for the treatment of several inflammatory diseases in the form of powders and decoctions. Similarly there are many reports that P.

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The α-glucosidase inhibitory potential of Tribulus terrestris extracts has been reported but as yet the active ingredients are unknown. This study attempted to isolate the responsible metabolites and elucidate their inhibition mechanism of α-glucosidase. By fractionating T.

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Tyrosinase inhibition may be a means to alleviate not only skin hyperpigmentation but also neurodegeneration associated with Parkinson's disease. In the course of metabolite analysis from tyrosinase inhibitory methanol extract (80% inhibition at 20 μg/ml) of Campylotropis hirtella, we isolated fourteen phenolic compounds, among which neorauflavane 3 emerged as a lead structure for tyrosinase inhibition. Neorauflavane 3 inhibited tyrosinase monophenolase activity with an IC50 of 30 nM.

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Protein tyrosine phosphatase 1B (PTP1B) is an important target to treat obesity and diabetes due to its key roles in insulin and leptin signaling. The MeOH extracts of the root bark of Flemingia philippinensis yielded eight inhibitory molecules (1-8) capable of targeting PTP1B. Three of them were identified to be novel compounds, philippin A (1), philippin B (2), and philippin C (3) which have a rare 3-phenylpropanoyl chromenedione skeleton.

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