Publications by authors named "Yoon-Joo Ko"

Anderss (Salicaceae), commonly referred to as Korean willow, is native to East Asia, particularly Korea and China, and it has been used in traditional Korean folk medicine for its potent anti-inflammatory, analgesic, and antioxidant properties. In our ongoing research efforts to discover biologically new natural products, phytochemical analysis on an ethanolic extract of twigs yielded the isolation and identification of ten phenolic compounds (-), including a newly discovered phenolic glycoside () named isograndidentatin D, isolated via HPLC purification. The structure of compound was determined through extensive 1D and 2D NMR spectral data analysis and high-resolution electrospray ionization mass spectrometry (HR-ESIMS).

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, commonly known as the bonnet bellflower or deodeok, is primarily found in Eastern Asia. Its roots have been used traditionally across Asia to treat various ailments such as bronchitis, coughs, asthma, and inflammation. In our ongoing efforts to discover bioactive natural products, a phytochemical investigation of the -BuOH fraction of root extracts led to the isolation and identification of a new indole alkaloid -glycoside, deodeokaloid (D-indole-3-lactic acid -β-D-glucopyranoside) (), alongside known compounds tangshenoside I (), tangshenoside IV (), and chlorogenic acid () through HPLC purification.

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Protectins, 10,17-dihydroxydocosahexaenoic acids (10,17-DiHDHAs), are belonged to specialized pro-resolving mediators (SPMs). Protectins are generated by polymorphonuclear leukocytes in humans and resolve inflammation and infection in trace amounts. However, the quantitative production of protectin DX 10-epimer (10-epi-PDX, 10R,17S-4Z,7Z,11E,13Z,15E,19Z-DiHDHA) has been not attempted to date.

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A targeted metabologenomic method was developed to selectively discover terminal oxazole-bearing natural products from bacteria. For this, genes encoding oxazole cyclase, a key enzyme in terminal oxazole biosynthesis, were chosen as the genomic signature to screen bacterial strains that may produce oxazole-bearing compounds. Sixteen strains were identified from the screening of a bacterial DNA library (1,000 strains) using oxazole cyclase gene-targeting polymerase chain reaction (PCR) primers.

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Kimura, commonly known as pussy willow, is a deciduous shrub and tree belonging to the Salicaceae family. The genus spp. has been known as a healing herb for the treatment of fever, inflammation, and pain relief.

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This work shows that hollow Ru/RuO nanoparticles having nanoparticulate shells (HN-Ru/RuO) can be prepared using hollow microporous organic polymers with Ru species (H-MOP-Ru) as precursors. Using silica spheres as templates, H-MOPs were prepared through the Sonogashira-Hagihara coupling of 1,3,5-triethynylbenzene with 2,3-ethoxymethylenedioxy-1,4-diiodobenzene. Acid hydrolysis of cyclic ethyl orthoformate protecting groups generated catechol moieties to form H-MOP-Cat.

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holds a longstanding place in traditional herbal medicine, primarily utilized for addressing skin infections, acting as antipyretics, diuretics, and purgatives. In this study, our primary objective was to investigate the secondary metabolites present in leaves, with the aim of pinpointing natural compounds exhibiting potential antiviral activities. Five secondary metabolites (-), including an auronol glycoside (), two coumarins ( and ), a chromane () and a gallotannin (), were isolated from leaves.

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A targeted and logical discovery method was devised for natural products containing piperazic acid (Piz), which is biosynthesized from ornithine by l-ornithine -hydroxylase (KtzI) and - bond formation enzyme (KtzT). Genomic signature-based screening of a bacterial DNA library (2020 strains) using polymerase chain reaction (PCR) primers targeting identified 62 strains (3.1%).

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Article Synopsis
  • A new targeted discovery method was developed to efficiently identify natural macrolactams, using a combination of genomic and spectroscopic techniques to screen bacterial DNA libraries.
  • Out of 1,188 strains tested, 43 were identified as potential macrolactam producers, leading to the discovery of known and previously unreported macrolactams.
  • The method revealed significant cytotoxic properties in one compound against cancer cells, demonstrating its potential for discovering new natural products with bioactive properties.
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Various factors related to growing conditions can influence the nutritional quality of plants, including vegetable crops, especially the contents of health-promoting phytochemicals. In this study, the phytochemical contents of spinach (Spinacia oleracea) cultivated under greenhouse and open field conditions were comparatively analyzed using a metabolomic approach with Mass Profiler Professional (MPP) software. S.

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Three isoindolinone alkaloids (-), including one new isoindolinone-type alkaloid, meyeroguilline E (), and six other known compounds (-) were isolated from the poisonous mushroom (Agaricaceae). The structure of the new compound was determined using extensive spectroscopic analyses via one-dimensional (1D) and two-dimensional (2D) NMR data interpretation and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). To the best of our knowledge, compound is the first example of a natural isoindolinone with a butanoic acid moiety, and this study is the first to detect the other known compounds (-) in .

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This work shows that hydroboration can be efficiently applied to the postsynthetic modification (PSM) of the Sonogashira-Hagihara coupling-based microporous organic polymers (MOPs). Hollow MOPs (H-MOPs) were prepared by template synthesis through the Sonogashira-Hagihara coupling of tetra(4-ethynylphenyl)methane with 1,4-diiodobenzene. The H-MOPs were used as platforms in the PSM-based functionalization.

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Embedding metal-halide perovskite particles within an insulating host matrix has proven to be an effective strategy for revealing the outstanding luminescence properties of perovskites as an emerging class of light emitters. Particularly, unexpected bright green emission observed in a nominally pure zero-dimensional cesium-lead-bromide perovskite (CsPbBr) has triggered intensive research in better understanding the serendipitous incorporation of emissive guest species within the CsPbBr host. However, a limited controllability over such heterostructural configurations in conventional solution-based synthesis methods has limited the degree of freedom in designing synthesis routes for accessing different structural and compositional configurations of these host-guest species.

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Article Synopsis
  • - The study investigated the traditional use of the fruit known as Fructus for treating gastric issues, focusing on its antibacterial properties against unspecified strains.
  • - Nine chemical compounds were isolated from the ethanol extract of Fructus, with one compound demonstrating strong antibacterial activity, comparable to metronidazole.
  • - Techniques like NMR and mass spectrometry were used to determine the structure and absolute configuration of the compounds, revealing a potential for further research on their medicinal properties.
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As part of ongoing systematic research into the discovery of bioactive secondary metabolites with novel structures from Korean wild mushrooms, we investigated secondary metabolites from a poisonous mushroom, (Kawam.) Kirchm. & O.

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Phenalenone derivatives sourced from fungi are polyketides that have attracted significant interest because of their diverse chemical structures and potential bioactivities. As part of our ongoing quest to discover novel natural products with biological properties from diverse natural resources, three unreported phenalenone derivatives (1-3), named ent-12-methoxyisoherqueinone (1), (-)-scleroamide (2), and (+)-scleroamide (3), together with four known phenalenone derivatives, ent-atrovenetinone (4), isoherqueinone (5), herqueinone (6), and ent-peniciherquinone (7) were isolated from the Hawaiian soil fungus Penicillium herquei FT729, collected on the Big Island, Hawaii. Compounds 2 and 3 were enantiomers, which were separated using a chiral-phase HPLC column, which provided optically pure compounds 2 and 3.

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(Scop.) Sing., a mushroom of the family , has been used in traditional oriental medicine to treat cholecystitis, improve bile secretion, and regulate bile-duct pressure.

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Lipoxygenases (LOXs) biosynthesize lipid mediators (LMs) as human signaling molecules. Among LMs, specialized pro-resolving mediators (SPMs) are involved in the resolution of inflammation and infection in humans. Here, the putative LOX from the bacterium Sphingopyxis macrogoltabida was identified as arachidonate 9S-LOX.

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Eight compounds (1-8) including one novel nitrophenyl glycoside, ginkgonitroside (1) were isolated from the leaves of Ginkgo biloba, a popular medicinal plant. The structure of the new compound was characterized using extensive spectroscopic analyses via 1D and 2D NMR data interpretations, HR-ESIMS, and chemical transformation. To the best of our knowledge, the present study is the first to report the presence of nitrophenyl glycosides, which are relatively unique phytochemicals in natural products, in G.

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(-)-α-Bisabolol is a functional ingredient in various health and cosmetic products and has antibacterial, anti-inflammatory, and wound healing properties. (-)-α-Bisabolol is chemically synthesized and produced by steam distillation of essential oils extracted from Brazilian Candeia (). To sustainably produce pure (-)-α-bisabolol, we previously engineered to produce 9.

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Rechargeable calcium batteries have attracted increasing attention as promising multivalent ion battery systems due to the high abundance of calcium. However, the development has been hampered by the lack of suitable cathodes to accommodate the large and divalent Ca ions at a high redox potential with sufficiently fast ionic conduction. Herein, we report a new intercalation host which presents 500 cycles with a capacity retention of 90% and a remarkable power capability at ~3.

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Telomeric repeat binding factor a (Terfa) derived from zebrafish is a homologous protein with human telomeric repeat binding factor 2 (TRF2). Terfa is known as a senescence-associated biomarker in various research through the zebrafish animal model. In addition, according to the findings so far, it has been confirmed that human or plant telomere binding proteins bind to telomeric DNA specialized for each species, but, in our result, Terfa shows it strongly binds to both human or plant type telomeric DNA.

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Ginkgo biloba (Ginkgoaceae), commonly known as "ginkgo", is called a living fossil, and it has been cultivated early in human history for various uses in traditional medicine and as a source of food. As part of ongoing research to explore the chemical diversity and biologically active compounds from natural resources, two new coumaric acid-aliphatic alcohol hybrids, ginkwanghols A (1) and B (2) were isolated from the leaves of G. biloba.

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This work shows that hollow microporous organic polymer (H-MOP-A) with activated internal alkynes as IR probes can be prepared by template synthesis based on acyl Sonogashira-Hagihara coupling at room temperature. The H-MOP-A is a versatile platform in the main chain PSM based on nonradical thiol-yne click reaction. Moreover, an IR peak of internal alkynes in the H-MOP-A is very intense and could be utilized in the monitoring of thiol-yne click-based main chain PSM.

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Rhubarb is a well-known herb worldwide and includes approximately 60 species of the genus. One of the representative plants is , which is prescribed as official rhubarb due to its pharmacological potential in the Korean and Chinese pharmacopoeia. In our bioactive screening, we found out that the EtOH extract of inhibited hepatic stellate cell (HSC) activation by transforming growth factor β1 (TGF-β1).

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