Publications by authors named "Ki Yong Lee"

As cellular senescence, reactive oxygen species (ROS) accumulate excessively, causing cellular damage. Flavonoids derived from natural products are known for their antioxidant effects and their ability to delay cellular senescence. Previous studies have attempted to mitigate cellular senescence using flavonoids from natural sources.

View Article and Find Full Text PDF

Interleukin (IL)-33, a member of the IL-1 cytokine family, plays a vital role in immune system regulation and inflammation, with oxidative stress being implicated in its expression. During the search for compounds from natural sources with potential as therapeutic agents for allergic diseases via IL-33 signal modulation, we discovered significant IL-33 inhibitory activity in the methanol extract of (sword bean) pods. Through chromatographic separation and liquid chromatography-mass spectrometry, we isolated 11 compounds (-) from the methanol extract.

View Article and Find Full Text PDF
Article Synopsis
  • Understanding plant metabolites across the plant kingdom is challenging due to their vast diversity.
  • Researchers created the plantMASST reference database with data from 19,075 plant extracts, covering 246 botanical families, 1,469 genera, and 2,793 species.
  • This database enhances research on plant molecules, supporting drug discovery, biosynthesis, taxonomy, and ecology related to herbivore interactions.*
View Article and Find Full Text PDF

Laser-based additive manufacturing processes, particularly direct energy deposition (DED), have gained prominence for fabricating complex, functionally graded, or customized parts. DED employs a high-powered heat source to melt metallic powder or wire, enabling precise control of grain structures and the production of high-strength objects. However, common defects, such as a lack of fusion and pores between layers or beads, can compromise the mechanical properties of the printed components.

View Article and Find Full Text PDF

Viral hemorrhagic septicemia causes considerable economic losses for Korea's olive flounder (Paralichthys olivaceus) aquaculture farms; therefore, effective antiviral agents for controlling viral hemorrhagic septicemia virus (VHSV) infection are imperative. The present study implemented a Box-Behnken design and cytopathic reduction assay to derive an optimized extract of Sanguisorba officinalis L. roots (OE-SOR) with maximum antiviral activity against VHSV.

View Article and Find Full Text PDF

The identification of molecular structure is essential for understanding chemical diversity and for developing drug leads from small molecules. Nevertheless, the structure elucidation of small molecules by Nuclear Magnetic Resonance (NMR) experiments is often a long and non-trivial process that relies on years of training. To achieve this process efficiently, several spectral databases have been established to retrieve reference NMR spectra.

View Article and Find Full Text PDF

High thermal conductivity steel (HTCS-150) is deposited onto non-heat-treated AISI H13 (N-H13) via powder-fed direct energy deposition (DED) based on the response surface methodology (RSM) to enhance the mechanical properties and thermal conductivity of N-H13, which is generally used as a hot-work tool steel. The main process parameters of the powder-fed DED are priorly optimized to minimize defects in the deposited regions and, therefore, to obtain homogeneous material properties. The deposited HTCS-150 is comprehensively evaluated through hardness, tensile, and wear tests at the different temperatures of 25, 200, 400, 600, and 800 °C.

View Article and Find Full Text PDF

Cordycepin, also known as 3'-deoxyadenosine, is a major active ingredient of with diverse pharmacological effects. Due to its limited supply, many attempts have been conducted to enhance the cordycepin content. As part of this study, eight medicinal plants were supplemented with cultivation substrates of to increase the cordycepin content.

View Article and Find Full Text PDF
Article Synopsis
  • * The ethanol extract from DC. var. Pit. significantly reduced nitric oxide levels in vitro, and researchers identified 11 compounds, including a new one named gouanioside A.
  • * The study suggests that gouanioside A could be a potential treatment for inflammatory diseases, as it affects nitric oxide synthesis in immune cells.
View Article and Find Full Text PDF

Species belonging to the (Asteraceae), the largest genus in the tribe Vernonieae (consisting of about 1,000 species), are widely used in food and medicine. These plants are rich sources of bioactive sesquiterpene lactones and steroid saponins, likely including many as yet undiscovered chemical components. A phytochemical investigation resulted in the separation of three new stigmastane-type steroidal saponins (1 - 3), designated as vernogratiosides A-C, from whole plants of .

View Article and Find Full Text PDF
Article Synopsis
  • The study investigated the biological activity and chemical constituents of kuding tea (ssp. Gogel) from Southeast Asia, revealing its antioxidant and α-glucosidase inhibitory properties.
  • Analysis showed significant differences in metabolite profiles between its roots, leaves, and stems, with 25 compounds isolated, including 18 xanthones and 5 flavonoids.
  • Optimized extraction conditions (using methanol in ethyl acetate) yielded high biological activity, with potential applications for combating oxidative stress-related metabolic diseases.
View Article and Find Full Text PDF

The cell extraction method coupled with LC-QTOF-MS/MS is a biological screening technique in which cells are incubated with extracts of natural products, which results in potential bioactive compounds selectively combining with various extracellular and intracellular targets. Although the neuroprotective effects of the plant Polygonum tinctorium are unknown, the ethyl acetate (EtOAc) fraction exhibits significant neuroprotective effects against ʟ-glutamate-induced cytotoxicity in HT22 cells. In this study, we attempted to identify the neuroprotective compounds in the EtOAc fraction of P.

View Article and Find Full Text PDF

In our previous research on Vietnamese medicinal plants, we found that the ethanolic extract of the aerial parts of Paris polyphylla var. chinensis exhibited cytotoxic effects in vitro in the MCF-7 human cancer cell line. Here, we used combined chromatographic separations to isolate six compounds including a new steroid glycoside, paripoloside A (3), and five known compounds, from the butanol extract of the aerial parts of P.

View Article and Find Full Text PDF
Article Synopsis
  • The study explored how skin microbiota is crucial for skin health and how disturbances can lead to harmful microorganisms, aiming to create a red ginseng formulation that promotes good bacteria.
  • Methods involved testing the formulation’s effects on bacterial growth, combining it with preservatives, and conducting a clinical trial with 20 female subjects to assess changes in their skin microbiome.
  • Results showed that the red ginseng formulation improved the growth of beneficial bacteria while reducing overall microbial diversity, indicating its potential for maintaining healthy skin microbiome.
View Article and Find Full Text PDF
Article Synopsis
  • The text discusses a gram-negative pathogen that is opportunistic and can lead to infections, especially in people with weakened immune systems.* -
  • This pathogen forms biofilms and uses a communication system called quorum sensing to produce virulence factors, which helps it resist antibiotics.* -
  • The review focuses on targeting a specific quorum sensing system (RhlI/RhlR) with small molecules to inhibit biofilm formation and features recent studies on potential new anti-biofilm agents.*
View Article and Find Full Text PDF

Phytochemical investigation of the whole plants of Hance. led in the isolation and identification of two new stigmastane-type steroidal glucosides (-), namely vernogratiosides A (), and B (). Their chemical structures were fully elucidated based on 1 D/2D NMR spectroscopic, HR-ESI-MS data analyses, and by producing derivatives by chemical reactions.

View Article and Find Full Text PDF

Breast cancer is one of the most common malignant tumors in women worldwide, and is a major cause of mortality and morbidity in cancer patients. Constitutive activation of STAT3 has been found in a variety of malignant tumors, including breast cancer. Since STAT3 activation is capable of regulating various important features of tumor cells, identification of a novel STAT3 inhibitor is considered a potential strategy for treating breast cancer.

View Article and Find Full Text PDF
Article Synopsis
  • Zoonotic bacteria pose significant health risks in aquaculture, impacting not only fish but also humans through clinical effects.* -
  • A study on 22 isoflavones revealed that adding prenyl groups enhances their antibacterial properties, with some compounds achieving minimum inhibitory concentrations (MIC) of 1.95-500 μg/mL.* -
  • The ripe fruit extracts (MTF) showed the greatest antibacterial activity, optimized via specific extraction conditions, making them potential eco-friendly treatments for streptococcosis in aquaculture.*
View Article and Find Full Text PDF

As the leaf of has shown antioxidant activity, a study was conducted to identify the active ingredients. Forty-eight compounds were isolated from the leaves of through various chromatographic techniques. Further characterization of the structures on the basis of 1D and 2D NMR and MS data identified several aromatic compounds, including phenylpropanoid derivatives, phenolics, coumarins, flavonoids and lignans.

View Article and Find Full Text PDF

Alzheimer's disease (AD) is a severe neurodegenerative disorder. AD is pathologically characterized by the formation of intracellular neurofibrillary tangles, and extracellular amyloid plaques which were comprised of amyloid-beta (Aβ) peptides. Aβ induces neurodegeneration by activating microglia, which triggers neurotoxicity by releasing various inflammatory mediators and reactive oxygen species (ROS).

View Article and Find Full Text PDF

The composition of a plant, together with its efficacy, vary depending on its maturity and plant parts. In this study, the chemical constituents of immature fruits of Maclura tricuspidata (Moraceae) were investigated together with their anti-diabetic and antioxidant effects. A total of 34 compounds were isolated from the immature fruits of M.

View Article and Find Full Text PDF

Baicalein (5,6,7-trihydroxy-2-phenyl-4H-1-benzopyran-4-one), a flavonoid analog from , possesses several pharmacological activities including antioxidant, antiproliferative, and anti-inflammatory activities. We previously reported that baicalein inhibits the thymic stromal lymphopoietin (TSLP)/TSLP receptor (TSLPR) signaling pathways and can be used as an active ingredient in the treatment of asthma and atopic dermatitis. However, baicalein is rapidly metabolized to baicalin and baicalein-6--glucuronide in vivo, which limits its preclinical and clinical use.

View Article and Find Full Text PDF

Interleukin-33 (IL-33) is an epithelial-derived cytokine that plays an important role in immune-mediated diseases such as asthma, atopic dermatitis, and rheumatoid arthritis. Although IL-33 is considered a potential target for the treatment of allergy-related diseases, no small molecule that inhibits IL-33 has been reported. Based on the structure-activity relationship and in vitro 2D NMR studies employing N-labeled IL-33, we identified that the oxazolo[4,5-c]-quinolinone analog 7 c binds to the interface region of IL-33 and IL-33 receptor (ST2), an orphan receptor of the IL-1 receptor family.

View Article and Find Full Text PDF

Thymic stromal lymphopoietin (TSLP) plays an important role in the pathophysiology of various allergic diseases that are mediated by T helper cell type-2 (Th2) responses, including asthma and atopic dermatitis. The primary focus of this study was the identification of potent inhibitors of the TSLP signaling pathway for potential therapeutic use. The 80% methanol extract of bark significantly inhibited the signal transducer and activator of transcription 5 (STAT5) phosphorylation in human mast cell (HMC)-1 cells.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionok03ugj0534iroaq7bjeti53bsnl48an): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once