A5101547427- Microbial Natural Products and Biosynthesis
- Antibiotic Resistance in Bacteria
- Bacterial biofilms and quorum sensing
- Marine Sponges and Natural Products
- Bacterial Genetics and Biotechnology
- Microbial bioremediation and biosurfactants
- Genomics and Phylogenetic Studies
- Insect symbiosis and bacterial influences
- Microbial Community Ecology and Physiology
- Chromium effects and bioremediation
- Natural product bioactivities and synthesis
- Plant and animal studies
- Vibrio bacteria research studies
- Plant biochemistry and biosynthesis
- Insect and Arachnid Ecology and Behavior
- Biological Activity of Diterpenoids and Biflavonoids
- Antimicrobial Peptides and Activities
- Entomopathogenic Microorganisms in Pest Control
- Antibiotics Pharmacokinetics and Efficacy
- Phytochemical compounds biological activities
- Lepidoptera: Biology and Taxonomy
- Synthetic Organic Chemistry Methods
- Bioactive Compounds and Antitumor Agents
- Nutritional Studies and Diet
- Biocrusts and Microbial Ecology
Mokpo National University
2023
Korea University
2015-2021
Seoul National University
1988-2021
St. Vincent's Hospital
2016
Confocal and scanning electron microscopic observations have previously shown the strong bacterial association of Microcystis aeruginosa cells on their surfaces. DNA-based analyses associated communities were carried out using two M. strains grown in laboratory eight newly collected cyanobacterial bloom samples. was most predominant species (66-100%) within phylum Cyanobacteria. Rhizobium, Hydrogenophaga Brevundimonas commonly found, Flavobacterium present all In total, 396 colonies from...
Modification of the outer membrane charge by a polymyxin B (PMB)-induced PmrAB two-component system appears to be dominant phenomenon in PMB-resistant Acinetobacter baumannii. variants and many clinical isolates also appeared produce vesicles (OMVs). Genomic, transcriptomic, proteomic analyses revealed that upregulation pmr operon decreased membrane-linkage proteins (OmpA, OmpW, BamE) are linked overproduction OMVs, which promoted enhanced biofilm formation. The addition OMVs from into...
Coprisidins A and B (1 2) were isolated from a gut-associated Streptomyces sp. in the dung beetle Copris tripartitus. Using combination of spectroscopic techniques, structures compounds determined to be first examples natural naphthoquinone–oxindole alkaloids. Coprisidin was found inhibit action Na+/K+-ATPase, coprisidin showed activity for induction NAD(P)H:quinone oxidoreductase 1.
Summary Acinetobacter oleivorans DR 1 can utilize C 12 –C 30 alkanes as a sole carbon source but not short‐chain (C 6 , 10 ). Two copies of each alkB ‐, almA ‐ and ladA ‐type alkane hydroxylase ( AH ) are present in the genome cells. Expression mutational analyses s showed that alkB1 alkB2 major ‐encoding genes under roles other negligible. Our data suggested AlkB1 is responsible for long‐chain utilization 24 26 ), AlkB2 important medium‐chain 16 metabolism. Phylogenetic revealed large...
Chemical studies of gut bacteria the carpenter ant Camponotus kiusiuensis led to discovery two new alkaloids, camporidines A and B (1 2), from Streptomyces sp. STA1. The structures 1 2 were established as polyketide alkaloids bearing a piperidine–cyclopentene–epoxide 6/5/3 tricyclic system based on NMR spectroscopic mass spectrometric analysis. relative configurations determined by their 1H–1H NOESY/ROESY 1D NOE correlations. experimental ECD spectra compared with calculated assign absolute...
Dumulmycin (1) was isolated from Streptomyces sp. DM28, a bacterial strain riverine sediment sample. The structure of 1 elucidated as bicyclic macrolide possessing 19-membered and 5-membered rings by spectroscopic analysis. stereochemistry determined J-based configuration analysis, ROESY NMR data, DP4 calculations, the modified Mosher's method. Genetic analysis identified trans-acyltransferase polyketide biosynthetic gene cluster for 1. exhibited in vitro antitubercular activity (MIC50 = 27.1 μM).
Difficulties involved in treating drug-resistant pathogens have created a need for new therapies. In this study, we investigated the possibility of using oleanolic acid (OA), natural pentacyclic triterpenoid, as adjuvant antibiotics against Acinetobacter baumannii. High concentrations OA can kill cells, partly because it generates reactive oxygen species. Measurement fractional inhibitory concentration (FIC) and time-kill experiments demonstrated that only synergizes with aminoglycoside...
Salinazinones A (1) and B (2), two unprecedented pyrrolidinyl-oxazinones, were isolated from the culture broth of Streptomyces sp. KMF-004 a solar saltern at Aphae Island, Korea. The structures these salinazinones, which are unusual consist 2-methylpropenyl-1,3-oxazin-6-one bearing 1-oxopyrrolidinyl substituents, assigned by spectral chemical analyses using Mosher's method, circular dichroism (CD), calculated ECD. first examples natural alkaloid class composed an oxazinone–pyrrolidone conjugate.
A new secondary metabolite, actinomadurol (1), was isolated along with the known compound JBIR-65 (2) from a rare actinomycete, Actinomadura strain KC 191. The structure of 1 established as member bacterial C-19 norditerpenoid class by NMR data and ECD calculations. absolute configuration 2, which previously reported without stereochemical analysis, determined using modified Mosher's method Actinomadurol (1) exhibited potent antibacterial activity against pathogenic strains, such...
Bacterial alkane metabolism is associated with a number of cellular stresses, including membrane stress and oxidative stress, the limited uptake charged ions such as sulfate. In present study, genes ssuD tauD in Acinetobacter oleivorans DR1 cells, which encode an alkanesulfonate monooxygenase taurine dioxygenase, respectively, were found to be responsible for hexadecanesulfonate (C16SO3H) metabolism, Cbl was experimentally identified potential regulator expression. The expression occurred...
Two new macrolides, formicolides A (1) and B (2), were isolated from Streptomyces sp. BA01, a gut bacterial strain of the wood ant (Formica yessensis). Their 20-membered macrocyclic lactone structures established using NMR mass spectrometric data. The relative configurations determined by J-based configuration analysis utilizing ROESY, HETLOC, HECADE spectroscopic Genomic bioinformatics enabled us to identify type-I polyketide synthase pathway employing trans-acyltransferase system. absolute...
Formicins A-C (1-3) were discovered from Streptomyces sp. associated with wood ants. The structures of 1 and 2 elucidated as indenone thioesters bearing N-acetylcysteamine based on spectroscopic analysis. configurations 1-3 determined by the analysis ROESY correlations, phenylglycine methyl ester method, chemical derivatization 3 to 2. Formicin A inhibited growth human triple-negative breast cancer cells regulating liver kinase B1-mediated AMPK signaling pathway.
The aceA and glcB genes, encoding isocitrate lyase (ICL) malate synthase, respectively, are not in an operon many bacteria, including Pseudomonas aeruginosa, unlike Escherichia coli. Here, we show that expression of P. aeruginosa is specifically upregulated under H2O2-induced oxidative stress iron-limiting conditions. In contrast, the addition exogenous redox active compounds or antibiotics increases glcB. transcriptional start sites conditions presence iron were found to be identical by 5'...
Indole, which is widespread in microbial communities, has received attention because of its effects on bacterial physiology. Pseudomonas putida and aeruginosa can acquire ampicillin (Amp) resistance during growth indole-Amp agar. Transcriptome, mutant, inhibitor studies have suggested that Amp induced by indole be attributed to increased gene expression ttgAB encoding two genes RND-type multidrug efflux operons an ampC β-lactamase. Expression, enzyme activities, mutational analyses indicated...
Four new prenylated xanthones, cudracuspixanthones A–D (1–4), two benzophenones, cudracuspiphenones A (5) and B (6), 11 known xanthones (7–17) were isolated from the roots of Cudrania tricuspidata. The absolute configurations compounds 2–4 deduced by comparison calculated optical rotation values with measured data. Compounds 1, 5, 6 showed moderate antiproliferative activity on HSC-T6 cells IC50 9.7, 3.3, 7.1 μM, respectively. 2–4, 10, 14–16 had weaker activity. Flow cytometric analysis...
Four new aminoglycolipids, deinococcucins A-D (1-4), were discovered from a Deinococcus sp. strain isolated the gut of queen carpenter ants, Camponotus japonicus. The structures elucidated as combination N-acetyl glucosamine, 2,3-dihydroxypropanoic acid, and an alkyl amine with C16 or C17 hydrocarbon chain primarily based on 1D 2D NMR mass spectroscopic data. exact location olefinic double bond in C D (3 4) was assigned liquid chromatography-mass spectroscopy data obtained after olefin...
Despite numerous efforts to discover novel bioactive products from microorganisms, previously reported compounds are repetitively reisolated. A new polyketide glycoside, gordonic acid (1), isolated the mixed culture of two Gram-positive bacteria, Gordonia sp. KMC005 and Streptomyces tendae KMC006, is reported. The structure 1 was characterized as an acyclic polyene substituted with a β-d-digitoxopyranose through NMR, HR-ESI-QTOF-MS, IR, UV spectral data. stereochemistry for determined by...
A marine-derived Streptomyces strain, SSC21, was isolated from the sediment of Suncheon Bay, Republic Korea. Chemical analysis bacterial strain resulted in isolation four new metabolites, suncheonosides A–D (1–4, respectively), each bearing a sulfur atom. The planar structures were identified as hexasubstituted benzothioate glycosides by combined spectroscopic analyses. Analysis configuration sugar moieties based on ROESY nuclear magnetic resonance correlations, one-bond 1H–13C coupling...