Publications by authors named "Ohshiro T"

Celludinones A and B, isolated from the fungus Talaromyces cellulolyticus BF-0307, were inhibitors of sterol O-acyltransferase (SOAT). Further searches for their congeners in the culture broth of the fungus by LC/UV and LC/MS analysis resulted in the discovery of four structurally related compounds, including a new dihydroisobenzofuran named celludinone C (1). The structure of 1, including its absolute stereochemistry, was elucidated by 1D/2D NMR and electronic circular dichroism (ECD) spectra.

View Article and Find Full Text PDF

A new drimane sesquiterpene ester, designated insuetusolate (1), and four reported ones (2-5) were isolated from a culture broth of Aspergillus insuetus BF-1613. The chemical structure of 1 was elucidated by extensive spectroscopic analyses, including MS and NMR. Compound 1 has a drimane-type sesquiterpene core with a 2'E,4'E,6'E-octatrienoate side chain.

View Article and Find Full Text PDF

Acetylation of lysine, a component of histones, regulates transcriptional activity. Simple detection methods for acetyl lysine are essential for early diagnosis of diseases and understanding of the physiological effects. We have detected and recognized acetyl lysine at the single-molecule level by combining MCBJ measurement and machine learning.

View Article and Find Full Text PDF

Unlabelled: Mesophilic enzymes, which are active at moderate temperatures, may dominate enzymatic reactions even in the presence of thermophilic crude enzymes. This study was conducted to investigate this hypothesis with mesophilic inositol dehydrogenases (IolG and IolX) produced in HTA426. To ensure the efficient production of mesophilic enzymes, we first screened for promoters induced at moderate temperatures using transcriptome analysis and identified four genes highly expressed at 30°C in the thermophile.

View Article and Find Full Text PDF

Seriniquinone was isolated as a melanoma-selective anti-cancer agent from a culture broth of the marine-derived bacterium Serinicoccus marinus CNJ927 in 2014. It targets the unique small protein, dermcidin, which affects the drug resistance of cancer cells. Due to its significant activity against cancer cells, particularly melanoma, and its unique target, seriniquinone has been developed as a new pharmacophore.

View Article and Find Full Text PDF

Two new cyclic dipeptides, paranazzamides A (1) and B (2) containing a C7-prenylated tryptophan, were isolated from a culture broth of snake fungal disease-isolate Paranannizziopsis sp. UH-21. This is the first report on the new secondary metabolites from Paranannizziopsis sp.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers screened for new anti-mycobacterial agents against Mycobacterium avium complex (MAC) and discovered two new compounds called hydroxycapsimycin and brokamycin, along with ikarugamycin.
  • The structures of hydroxycapsimycin and brokamycin were determined using advanced spectroscopic techniques like 1D and 2D NMR.
  • Hydroxycapsimycin's absolute configuration was confirmed through single-crystal X-ray diffraction, while both brokamycin and ikarugamycin showed moderate effectiveness against drug-resistant strains of MAC.
View Article and Find Full Text PDF
Article Synopsis
  • MAC (Mycobacterium Avium Complex) is a severe disease caused by non-tuberculous mycobacteria (NTM), and recent research has isolated seven new compounds, mavintramycins A-G, from a specific bacterium culture as potential anti-MAC agents.* -
  • Mavintramycin A emerged as the most effective compound, showing strong inhibition against NTM and activity against over 40 strains, including those resistant to multiple drugs, and performing well in models of persistent infection.* -
  • The mechanism of action for mavintramycin A involves binding to 23S ribosomal RNA, thereby inhibiting protein synthesis in NTM, making it a promising candidate for treating MAC
View Article and Find Full Text PDF

Nectriatide 1a, a naturally occurring cyclic tetrapeptide, has been reported to a potentiator of amphotericin B (AmB) activity. In order to elucidate its structure-activity relationships, we synthesized nectriatide derivatives with different amino acids in solution-phase synthesis and evaluated AmB-potentiating activity against Candida albicans. Among them, C-and N-terminal protected linear peptides were found to show the most potent AmB-potentiating activity.

View Article and Find Full Text PDF

Objective: To elucidate the functional role of gamma-aminobutyric acid (GABA)-ergic inhibition in suppressing epileptic brain activities such as spike-wave discharge (SWD), we recorded electroencephalogram (EEG) in knockout rats for (), which encodes one of the two GABA-synthesizing enzymes in mammals. We also examined how anti-epileptic drug valproate (VPA) acts on the SWDs present in rats and affects GABA synthesis in the reticular thalamic nucleus (RTN), which is known to play an essential role in suppressing SWD.

Methods: Chronic EEG recordings were performed in freely moving control rats and homozygous knockout (-/-) rats.

View Article and Find Full Text PDF

Growing evidence of the potential habitability of Ocean Worlds across our solar system is motivating the advancement of technologies capable of detecting life as we know it-sharing a common ancestry or physicochemical origin with life on Earth-or don't know it, representing a distinct emergence of life different than our one known example. Here, we propose the Electronic Life-detection Instrument for Enceladus/Europa (ELIE), a solid-state single-molecule instrument payload that aims to search for life based on the detection of amino acids and informational polymers (IPs) at the parts per billion to trillion level. As a first proof-of-principle in a laboratory environment, we demonstrate the single-molecule detection of the amino acid L-proline at a 10 μM concentration in a compact system.

View Article and Find Full Text PDF

Geobacillus spp. are moderate thermophiles that can efficiently produce recombinant proteins. Considering the protein production exhibited by these species, we searched for robust promoters in Geobacillus kaustophilus HTA426.

View Article and Find Full Text PDF

A new antibiotic named haneummycin (1) was isolated from a culture broth of marine-derived Streptomyces sp. KM77-8 by solvent extraction and HPLC using a C4 column. The structure of 1 was elucidated including relative stereochemistry as a new 22-membered macrolide lactam associated with a cyclopentanone and three sugars by various spectroscopic analyses, such as MS and NMR.

View Article and Find Full Text PDF

Genomic information is essential for human health. Due to its large volume, genomic information can be potentially computed using quantum computers, which are rapidly developing. Genome analysis using quantum computers can accelerate the development of personalized medicine, innovative drugs, and novel diagnostics based on genomic information.

View Article and Find Full Text PDF

In single-molecule measurements, metal nanogap electrodes directly measure the current of a single molecule. This technique has been actively investigated as a new detection method for a variety of samples. Machine learning has been applied to analyze signals derived from single molecules to improve the identification accuracy.

View Article and Find Full Text PDF

The selective and sensitive sensing of neurochemicals is essential to decipher in-brain chemistry underlying brain pathophysiology. The recent development of flexible and multifunctional polymer-based fibers has been shown useful in recording and modulating neural activities, primarily electrical ones. In this study, we were able to realize fiber-based neurochemical sensing with high sensitivity and selectivity.

View Article and Find Full Text PDF

Chemical properties have been based on statistical averages since the introduction of Avogadro's number. The lack of suitable methods for counting identified single molecules has posed challenges to counting statistics. The selectivity, affinity, and mode of hydrogen bonding between base and small molecules that make up DNA, which is vital for living organisms, have not yet been revealed at the single molecule level.

View Article and Find Full Text PDF

Kita-Kyushu lung cancer antigen-1 (KK-LC-1), encoded by , is a cancer/testis antigen (CTA) and an attractive target for immunotherapy. Our previous study demonstrated frequent expression in gastric cancers (GCs) and non-tumor sites of the stomach with tumors. Additionally, there was a correlation with () infection.

View Article and Find Full Text PDF

A cell-based assay was conducted to screen microbial culture broths for potentiators of neutral lipid degradation in Chinese Hamster Ovary K1 cells. A total of 5,363 microbial cultures from fungi and actinomycetes were screened in this assay. Brefeldin A (1) from fungal cultures was found to promote the degradation of triacylglycerol (TG) with an EC of 2.

View Article and Find Full Text PDF

Since 2020, our hospital has introduced nurse practitioners( NP) into cardiovascular surgery with the aim to improve labor efficiency. A cardiovascular surgery NP has both pre- and postoperative roles. An NP is not only involved in a necessary intervention but also in an intervention as the first assistant regardless of regular or emergency surgery.

View Article and Find Full Text PDF

Geobacillus thermodenitrificans K1041 is an unusual thermophile that is highly transformable via electroporation, making it a promising host for screening genetic libraries at elevated temperatures. In this study, we determined its biological properties, draft genome sequence, and effective vectors and also optimized the electroporation procedures in an effort to enhance its utilization. The organism exhibited swarming motility but not detectable endospore formation, and growth was rapid at 60°C under neutral and relatively low-salt conditions.

View Article and Find Full Text PDF

Phenochalasin A, a unique phenol-containing cytochalasin produced by the marine-derived fungus Phomopsis sp. FT-0211, was originally discovered in a cell morphological assay of observing the inhibition of lipid droplet formation in mouse peritoneal macrophages. To investigate the mode of action and binding proteins, phenochalasin A was radio-labeled by I.

View Article and Find Full Text PDF
Article Synopsis
  • Researchers created a comprehensive single-cell atlas of pancreatic ductal adenocarcinoma (PDAC) by analyzing data from over 70 samples and more than 130,000 cells, enhancing understanding of the tumor's complexity and environment.
  • The application of this atlas helped reanalyze existing bulk transcriptomic studies and revealed key relationships between different cell types, indicating that high levels of tumor cells and fibroblasts are linked to worse patient outcomes.
  • The study identified distinct tumor clusters and their interactions with various fibroblast subtypes, providing insights into the signaling pathways that contribute to the heterogeneity within PDAC and offering a valuable reference for future research.
View Article and Find Full Text PDF

In ball games, individuals collaborate to enhance their team's performance by sharing images and ideas that have not been verbalized. One of a coach's roles is to ascertain whether players share a common understanding of their team's images so as to devise tactics. Accordingly, this study aimed to verify the hypothesis that sharing images such as tacit knowledge that has not been verbalized occurs in collective interaction when utterances increase substantially during problem-solving.

View Article and Find Full Text PDF

Fucoidans are hetero-sulfated polysaccharides that are widely distributed in brown algae and have been extensively studied for their various biological activities. The structure-function relationship of fucoidans remains unclear but can be studied using fucoidan-degrading enzymes (fucoidanases). Here, we isolated and identified Flavobacterium sp.

View Article and Find Full Text PDF