Publications by authors named "Imada C"

Chemical investigation of the fermentation products of a deep sea water-derived actinomycete, sp. KD439, identified seven new angucyclinones, designated as kumemicinones A-G (-), together with the known SF2315B and miaosporone E. NMR and MS spectroscopic analyses, combined with X-ray crystallography and quantum chemical calculations of NMR chemical shifts and electronic circular dichroism (ECD) spectra, uncovered the structures of new angucyclinones as regioisomers of SF2315B at the allyl alcohol unit ( and ), an epoxy ring-opened γ-hydroxy enone isomer (), a B/C-ring-rearranged product (), or dimers with a new mode of bridging (-), adding new structural variation to this antibiotic group.

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This study aimed to investigate the protective effect of the metabolites produced by a new strain BF1-13, isolated from deep seawater (DSW), on the intestinal epithelial barrier against the dysfunction induced by hydrogen peroxide (HO) and to elucidate the mechanism underlying the effect. Protective effect of the metabolites by strain BF1-13 on the barrier function of the intestinal epithelial model treated with HO was investigated by the transepithelial electrical resistance (TEER). The metabolites enhanced the Claudin-4 (CLDN-4) expression, including at the transcription level, indicated by immunofluorescence staining and quantitative RT-PCR.

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Three new tetronate-class polyketides, nomimicins B, C, and D, along with nomimicin, hereafter named nomimicin A, were isolated from the culture extract of sp AKA43 collected from floating particles in the deep-sea water of Sagami Bay, Japan. The structures of nomimicins B, C, and D were elucidated through the interpretation of NMR and MS analytical data, and the absolute configuration was determined by combination of NOESY/ROESY and ECD analyses. Nomimicins B, C, and D showed antimicrobial activity against Gram-positive bacteria, and , with MIC values in the range of 6.

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We performed several experiments using three strains of Virgibacillus salexigens, namely, P2, NT N53, and C-20Mo (DSM 11483), which were isolated from completely different sources, in relation to bacteriocin production ability. Results of whole-genome sequencing analysis revealed that all strains have very similar sequences encoding class IId bacteriocin. Although a partial amino acid sequence of the purified bacteriocin produced by strain P2 isolated from fermented food was previously reported, whole-genome sequencing and the N-terminal sequencing results in this study showed that its complete amino acid sequence consisted of 48 residues, which corresponded to that of the hypothetical bacteriocin encoded by the gene in Virgibacillus massiliensis strain Vm-5 (DSM 28587) isolated from the human gut.

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A new enteromycin-class antibiotic, akazaoxime (), possessing an aldoxime functionality in place of -methyl nitronic acid, was isolated from the cultured extract of a marine-derived actinomycete of the genus , along with known A-76356 (). The structure of , including the absolute stereochemistry of three chiral centers, was established by comprehensive analysis of nuclear magnetic resonance (NMR) and mass spectrometry data coupled with magnetic anisotropy analysis of its phenylglycine methyl ester derivatives. The stereochemistry of , not determined previously, was proven to be the same as that of on the basis of the similarity of their NMR and specific rotation data.

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Article Synopsis
  • *Recent studies have shown that tocilizumab (TCZ), particularly when administered subcutaneously (TCZ-SC), can be effective for treating ASD that does not respond to standard therapies.
  • *In a case series involving three patients, TCZ-SC led to rapid fever resolution and normalization of inflammatory markers without serious side effects, suggesting it could be a viable and cost-effective treatment option for refractory ASD.
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In vivo-mimic silkworm infection models with Mycobacterium avium and Mycobacterium intracellulare were newly established to evaluate the therapeutic effects of anti-M. avium complex (MAC) antibiotics. Silkworms raised at 37°C died within 72 hours of an injection of M.

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A new diketopiperazine-like compound, designated protuboxepin K (1), was isolated together with the known structurally related protuboxepin A (2) from culture broth of the marine-derived fungal strain Aspergillus sp. BFM-0085 isolated from a sediment sample of Tokyo Bay. The structure of protuboxepin K was elucidated by spectroscopic data, including 1D and 2D NMR.

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A novel actinobacterium producing biosurfactant, designated OTB305, was isolated from marine sediment sampled at Otsuchi Bay, Iwate Prefecture, Japan and its taxonomic position was examined using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences exhibited that strain OTB305 was closely related to JCM 19630 (98.8 %) and DSM 42084 (98.

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Four new aromatic polyketides, konamycins A (1) and B (2) and rubromycins CA1 (3) and CA2 (4), were isolated from the culture extract of the tunicate-derived Streptomyces hyaluromycini MB-PO13. Compounds 1 and 2 possess a benzo[ b]fluorene aglycon modified by C-glycosylation with l-amicetose. Compounds 3 and 4 are the new congeners of rubromycin in which a naphthoquinone and carboxylated isocoumarin are joined through a spiroketal carbon.

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Tellurium (Te) has been increasingly used as a semiconductor material in copious amounts, with a concomitant increase in its discharge from industrial effluents and mining wastewater into the environment. However, soluble Te, such as tellurate (VI) and tellurite (IV), is toxic to organisms. Thus, highly efficient technologies need to be developed for a double-benefit detoxification and recovery of soluble Te from industrial and mining wastewater.

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In our screening program on marine-derived actinomycetes, Nonomuraea sp. AKA32 isolated from deep-sea water collected from a depth of 800 m in Sagami Bay, Japan was found to produce compounds cytotoxic to cancer cells. Activity-guided purification led to the isolation of a new aromatic polyketide, akazamicin (1), along with two known compounds, actinofuranone C (2) and N-formylanthranilic acid (3).

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A novel Gram-stain-positive actinobacterium, designated HT7-17T, was isolated from a sediment sample collected from the estuary of the Tama River, Japan, and its taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain HT7-17T was closely related to members of the genus Lysinimicrobium, with a similarity range of 97.1-98.

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A new cytotoxic agent designated isomethoxyneihumicin (1 and 2), a mixture of lactam-lactim tautomers, was isolated along with methoxyneihumicin (3) from the culture broth of the marine Nocardiopsis alba KM6-1. The structures of 1 and 2 were elucidated in spectroscopic analyses (1D and 2D NMR data, and ROESY correlations). Isomethoxyneihumicin (15.

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The distribution and characterization of bacteria including lactic acid bacteria (LAB) in the traditional and popular salted fish yegyo ngapi in Myanmar were studied to clarify the contribution of these bacteria to the curing and ripening of this product. Samples of yegyo ngapi purchased from a market in Yangon were used. Most of the isolates obtained using de Man, Rogosa and Sharpe medium containing 10 % NaCl were identified as coccoid LAB on the basis of their basic phenotypic characteristics.

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A new depsidone, named 7-chlorofolipastatin, and five known structurally related depsidones were isolated from the culture broth of the marine-derived fungus Aspergillus ungui NKM-007 by solvent extraction and HPLC using an octadecylsilyl column. The structure of 7-chlorofolipastatin was elucidated by various spectroscopic data including 1D and 2D NMR spectroscopy. 7-Chlorofolipastatin inhibited sterol O-acyltransferase (SOAT) 1 and 2 isozymes in cell-based and enzyme assays using SOAT1- and SOAT2-expressing Chinese hamster ovary (CHO) cells.

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A natural antibacterial-substance-producing gram-positive bacterium was isolated from terasi shrimp paste, a popular fermented product in Indonesia. This strain, a spore-forming and strictly aerobic bacterium, was identified as Virgibacillus salexigens by 16S rRNA gene sequence analysis. The antibacterial substance purified from the precipitated product in the culture supernatant of the strain using ammonium sulfate showed a broad inhibition spectrum against gram-positive bacteria, including a typical foodborne bacterium, namely, Listeria monocytogenes.

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Marine algae have unique defense strategies against microbial infection. However, their mechanisms of immunity remain to be elucidated and little is known about the similarity of the immune systems of marine algae and terrestrial higher plants. Here, we suggest a possible mechanism underlying algal immunity, which involves hexose oxidase (HOX)-dependent production of hydrogen peroxide (H2O2).

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A novel Gram-stain-positive actinomycete, designated MB-PO13(T), was isolated from a tunicate (Molgula manhattensis) collected in Tokyo Bay, Japan, and its taxonomic position was studied by a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain MB-PO13(T) was closely related to Streptomyces graminisoli JR-12(T) (99.72% 16S rRNA gene sequence similarity) and Streptomyces shenzhenensis 172115(T) (99.

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The aim of the present study was to investigate the bacterial community structures of deep-sea water (DSW) and surface seawater (SSW) samples in Japan by molecular biological techniques. DGGE analyses and pyrosequencing analysis revealed that bacterial community structures of DSW were diverse and differed from those of SSW. This is the first report on the horizontal variation of bacterial community structures of DSW throughout Japan.

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Granulomatosis with polyangiitis (GPA) is primary necrotizing vasculitis, which predominantly affects small to medium vessels. Herein, we describe a case of a 60-year-old female with GPA who developed inflammatory wall thickening localized in the aortic arch, upper abdominal aorta, and pulmonary artery. The wall thickening in the large vessels and other GPA lesions such as lung nodules and orbital mass had failed to respond to high-dose glucocorticoids combined with cyclophosphamide; however, all were successfully treated with rituximab.

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Purpose: The objective of this study was to improve the absorption behavior of N-251, a novel antimalarial drug, by preparing an appropriate self-nanoemulsifying drug delivery system (SNEDDS).

Methods: Two different types of SNEDDS formulations, medium-chain fatty acid-based SNEDDS (MC-SNEDDS) and long-chain fatty acid-based SNEDDS (LC-SNEDDS), were prepared based on pseudo-ternary phase diagram, and examined for their in vivo oral absorption behavior in rats.

Results: Oral dosing of MC-SNEDDS formulations significantly improved the bioavailability (BA) of N-251 compared with N-251 powders.

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Bioremediation technologies have strong potential use in the less costly and more environmentally friendly removal of highly toxic hexavalent-chromium (Cr(VI)) compared with physicochemical technologies. Several Cr(VI)-reducing bacteria have been isolated; however, there are few studies on Cr(VI)-resistant and Cr(VI)-reducing actinomycetes. In this study, Cr(VI)-reducing actinomycetes were screened from estuarine, marine, and terrestrial samples on the basis of Cr(VI)-resistant and Cr(VI)-reducing ability.

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