Publications by authors named "Jae-Seoun Hur"

Continuous use of synthetic fungicides has led to explosive emergence of fungicide-resistant microbes. Therefore, there are urgent needs for environmentally friendly antimicrobial agents with novel modes of action. This study investigated endolichenic fungi (ELF) as a source of antimicrobial compounds against various plant pathogens.

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An endophytic fungus, sp. NG-25, produces a set of structurally related polyketides including cercosporamide, phomodione, and usnic acid, among which, cercosporamide has been reported to have strong antifungal and anticancer activities. In this study, sp.

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Background: Lichens, traditionally considered as a simple partnership primarily between mycobiont and photobiont, are, in reality, complex holobionts comprised of a multitude of microorganisms. Lichen mycobiome represents fungal community residing within lichen thalli. While it is acknowledged that factors like the host lichen species and environmental conditions influence the structure of the lichen mycobiome, the existing research remains insufficient.

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A depside derivative, named pericodepside (), along with the known depside proatranorin III (), was isolated from the solid cultivation of an strain that heterologously expresses and that are involved in the biosynthesis of atranorin in a fruticose lichen, . The structure of was determined by 1D and 2D NMR and MS spectroscopic data. The structure of consisted of a depside-pericosine conjugate, with the depside moiety being identical to that found in , suggesting that acted as an intermediate during the formation of through the esterification process.

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Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content.

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Background: Lichens are symbiotic organisms composed of a fungus and a photosynthetic partner, which are key ecological bioindicators due to their sensitivity to environmental changes. The endolichenic fungi (ELF) living inside lichen thalli, are an important but understudied component of playing crucial ecological roles such as nutrient cycling and protection against environmental stressors. Therefore ELF community investigation is vital for fostering sustainable ecosystems and leveraging their ecological benefits.

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Article Synopsis
  • Lichens are made up of fungi and tiny plants that work together, and they also have other fungi living inside them called endolichenic fungi, which help the lichen survive in different ways.
  • Researchers studied two types of lichens and found out that the endolichenic fungi are less diverse and different from the fungi that live on the bark of trees nearby.
  • The endolichenic fungi have a simpler structure compared to the surrounding fungi, which helps scientists understand how these tiny ecosystems work.
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A recently bioinformatic analysis of genomic sequences of fungi indicated that fungi are able to produce more secondary metabolites than expected. Despite their potency, many biosynthetic pathways are silent in the absence of specific culture conditions or chemical cues. To access cryptic metabolism, 108 fungal strains isolated from various sites were cultured with or without sp.

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Lung cancer has the highest mortality rates worldwide. The disease is caused by environmental pollutants, smoking, and many other factors. Recent treatments include immunotherapeutics, which have shown some success; however, the search for new therapeutics is ongoing.

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Daldipyrenones A-C (-), three unprecedented caged xanthone [6,6,6,6,6] polyketides featuring a spiro-azaphilone unit, were discovered from an endolichenic fungus, 047188. The structures of - were determined by using spectroscopic analysis and chemical derivatization. Daldipyrenones are likely derived by combining a chromane biosynthesis intermediate, 1-(2,6-dihydroxyphenyl)but-2-en-2-one, and a spiro-azaphilone, pestafolide A, via radical coupling or Michael addition to form a bicyclo[2.

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Feature-based molecular networking analysis suggested the presence of naphthol tetramers in 047219, the same species but a different strain from one used previously for the discovery of naphthol trimers promoting adiponectin synthesis. The new tetramers were composed of 5-methoxy-4-naphthol, each of which was connected to one another in various positions. Targeted isolation afforded six previously unreported naphthol tetramers (-) together with 13 known polyketides (-) including naphthol monomers, dimers, and trimers.

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Lichens are known to produce many novel bioactive metabolites. To date, approximately 1,000 secondary metabolites have been discovered, which are predominantly produced by the lichen mycobionts. However, despite the extensive studies on production of lichen secondary metabolites, little is known about the responsible biosynthetic gene clusters (BGCs).

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Endolichenic fungi (ELF) produce specialized metabolites that have various medicinal properties. Inhibition of tumor angiogenesis efficaciously suppresses many types of cancer. This study aimed to discover novel antiangiogenic agents from specialized metabolite extracts of ELF strains isolated from Korean lichens.

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Since the floristic study of lichens at the Barton and Weaver Peninsulas of King George Island in 2006, there have been intense investigations of the lichen flora of the two peninsulas as well as that of Fildes Peninsula and Ardley Island in Maxwell Bay, King George Island, South Shetland Islands, maritime Antarctic. In this study, a total of 104 species belonging to 53 genera, are identified from investigations of lichens that were collected in austral summer seasons from 2008 to 2016. Phenotypic and molecular analyses were incorporated for taxonomic identification.

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Article Synopsis
  • Atraric acid (AA) is a phenolic compound that shows anti-androgen properties, making it suitable for a new topical treatment for alopecia.
  • The optimized formulation, AA-TF#15, demonstrated significantly improved absorption and drug deposition in the skin compared to a conventional AA solution, specifically showing an 8.77-fold increase in skin flux.
  • Tested on mice, AA-TF#15 resulted in a substantial 58.0% increase in hair regrowth compared to minoxidil and showed enhanced expression of proteins related to hair growth, indicating its potential as an effective treatment for androgenic alopecia.
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Endolichenic fungi are host organisms that live on lichens and produce a wide variety of secondary metabolites. Colorectal cancer stem cells are capable of self-renewal and differentiation into cancer cells, which makes cancers difficult to eradicate. New alternative therapeutics are needed to inhibit the growth of tumor stem cells.

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Colorectal cancer (CRC) is the third most deadly type of cancer in the world and continuous investigations are required to discover novel therapeutics for CRC. Induction of apoptosis is one of the promising strategies to inhibit cancers. Here, we have identified a novel compound, Libertellenone T (), isolated from crude extracts of the endolichenic fungus from sp.

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Adiponectin-synthesis-promoting compounds possess therapeutic potential to treat diverse metabolic diseases, including obesity and diabetes. Phenotypic screening to find adiponectin-synthesis-promoting compounds was performed using the adipogenesis model of human bone marrow mesenchymal stem cells. The extract of the endolichenic fungus 047215 significantly promoted adiponectin production.

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A new secondary metabolite, ulleungdolin (), was isolated from the co-culture of an actinomycete, sp. 13F051, and a fungus, 15S071. Based on the NMR, UV, and MS data, it was deduced that the planar structure of comprised an isoindolinone (IsoID) with an octanoic acid, a tripeptide, and a sugar.

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Endolichenic fungi (ELF), which live the inside the lichen thallus, contain many secondary metabolites that show various biological activities. Recent studies show that lichen and ELF secondary metabolites have antioxidant, antibacterial, antifungal, cytotoxic, and anticancer activities. Here, the effects of an ELF extract and its bioactive compounds were investigated on the H1975 cell line focusing on immune checkpoint marker inhibition.

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Lichen-forming fungi are mutualistic symbionts of green algae or cyanobacteria. We report the comparative analysis of six genomes of lichen-forming fungi in classes Eurotiomycetes and Lecanoromycetes to identify genomic information related to their symbiotic lifestyle. The lichen-forming fungi exhibited genome reduction via the loss of dispensable genes encoding plant-cell-wall-degrading enzymes, sugar transporters, and transcription factors.

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The new genus and species, is described from Jeju Island, Korea. This lichen is characterized by saxicolous, crustose, pale greenish-gray, partly finely filamentous, matt, smooth thallus, prominent convex brown to dark brown ascomata with a concolorous margin constricted at the dark brown base, 300-800 μm diameter, 200-250 μm high, without a distinct proper margin, adhering to the substratum ending in a minute byssoid white external part of cylindrical cells, fusiform 3-5 septate ascospores (17-23 × 4-5 μm). Phylogenetic analyses using ITS and mtSSU sequences place in the (Lecanorales).

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