研究者業績

臼杵 豊展

ウスキ トヨノブ  (Usuki Toyonobu)

基本情報

所属
上智大学 理工学部物質生命理工学科 教授
学位
学士(理学)(東北大学)
修士(理学)(東北大学)
博士(理学)(東北大学)

連絡先
t-usukisophia.ac.jp
研究者番号
50514535
J-GLOBAL ID
200901076489387829
researchmap会員ID
5000046104

学歴

 3

論文

 113
  • Futa Koyama, Justin Lamb, Moena Hirao, Noriyuki Suzuki, Masahiro Yoshizawa-Fujita, Toyonobu Usuki, Yumiko Suzuki
    Advanced Synthesis & Catalysis 2024年10月4日  
    With a number of biologically active members, 2‐aroylchromones are valuable synthetic targets. A direct route towards 2‐aroylchromones from 2‐(methylsulfonyl)chromones and aldehydes via NHC‐catalyzed C‐C bond formation was developed. Yields of the synthesized 2‐aroylchromones were up to 85%. Chromones with angioprotective or antibacterial properties were easily synthesized using the method developed. Additionally, the synthetic utility of the afforded chromones was demonstrated by using them to synthesize the anticancer compound wrightiadione and analogues of it.
  • Christian Nanga Chick, Francois Eya'ane Meva, Phillippe Belle Ebanda Kedi, Toyonobu Usuki
    2024年7月17日  査読有り責任著者
  • Eri Tanaka, Yukie Yokota, Masamitsu Urakawa, Toyonobu Usuki
    European Food Research and Technology 2024年4月21日  査読有り責任著者
  • Lokadi Pierre Luhata, Yusuke Yoshida, Toyonobu Usuki
    Bioorganic Chemistry 147 107389-107389 2024年4月  査読有り責任著者
  • Organic & Biomolecular Chemistry 22(23) 4637-4640 2024年4月  査読有り責任著者
  • Hiroaki Tanaka, Seiya Miyagi, Tomoko Morita, Hiroaki Ishii, Natsuki Mori, Kaho Oishi, Takemasa Sakaguchi, Toyonobu Usuki
    Helvetica Chimica Acta 107(2) 2024年2月8日  査読有り責任著者
    Abstract Umifenovir is a broad‐spectrum antiviral agent used to treat influenza in China and Russia, and it has been studied as an antiviral agent for the treatment of coronavirus disease 2019 (COVID‐19). We have previously reported the synthesis of novel umifenovir analogues and their biological evaluation with a focus on their inhibitory activity against the binding of the spike glycoprotein (S‐protein) of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) and the angiotensin‐converting enzyme 2 (ACE2) receptor; however, no strong inhibitory activity was observed from these analogues. In the present study, an additional set of umifenovir analogues was synthesized with replacement of the substituents at the 2‐, 3‐, and 4‐positions of the indole, and a cell‐based assay using SARS‐CoV‐2 (B.1.1) was performed to examine the antiviral activity of the analogues. We found that one of the newly synthesized umifenovir analogues exhibited antiviral activity and reduced the viral load to 0.06 % as compared to the control when it was assessed in the presence of nafamostat and marimastat, which inhibit cell‐surface viral entry. In contrast, when this analogue was evaluated without the addition of nafamostat or marimastat, it exhibited less antiviral activity, suggesting that the umifenovir analogue would exert antiviral activity mainly by inhibiting endosome‐mediated viral entry.
  • Ryosuke Tashiro, Riki Anzawa, Tomoo Inoue, Ayame Mikagi, Dan Ozaki, Keita Tominaga, Takashi Inoue, Tomohisa Ishida, Miki Fujimura, Toyonobu Usuki, Hidenori Endo, Kuniyasu Niizuma, Teiji Tominaga
    Bioorganic & medicinal chemistry 100 117602-117602 2024年2月1日  査読有り責任著者
    Moyamoya disease (MMD) is a cerebrovascular disease which is characterized by the chronic progression of steno-occlusive changes at the terminal portion of internal carotid arteries and the development of "moyamoya vessels." Dysregulation of the extracellular matrix is regarded as a key pathophysiology underlying unique vascular remodeling. Here, we measured the concentration of elastin crosslinkers desmosine and isodesmosine in the plasma of MMD patients. We aimed to reveal its diagnostic values of desmosines in the progression of steno-occlusive lesions. The concentrations of plasma desmosines were determined by liquid chromatography-tandem mass spectrometry. The temporal profiles of steno-occlusive lesions on magnetic resonance angiography were retrospectively evaluated, and the correlation between the progression of steno-occlusive changes in intracranial arteries and plasma desmosines concentrations was further analyzed. Plasma desmosines were significantly higher in MMD patients with disease progression compared to MMD patients without disease progression. Also, the incidence of disease progression was higher in MMD patients with plasma desmosines levels over limit of quantitation (LOQ) than those with plasma desmosines levels below LOQ. In conclusion, plasma desmosines could be potential biomarkers to predict the progression of steno-occlusive changes in MMD patients.
  • Lokadi Pierre Luhata, Yoshiko Iizuka, Ryotaro Eda, Hiroshi Uchida, Christian Nanga Chick, Makoto Kubo, Toyonobu Usuki
    Chemistry Letters 53(2) 2023年12月1日  査読有り責任著者
    Abstract Verbascoside (VB), a phenylpropanoid glycoside found in many medicinal plants, is attracting the attention of researchers due to its significant clinical value. This study, for the first time, attempted the green synthesis of silver nanoparticles (AgNPs) using VB as a reducing and capping agent. The synthesized VB–AgNPs were characterized using ultraviolet–visible, dynamic light-scattering, Fourier-transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray analyses. The cytotoxic potency against LX-2 human hepatic stellate cells was also investigated.
  • Shogo Satoh, Daria Baut, Moena Hirao, Daisuke Watanabe, Rina Suzuki, Toyonobu Usuki
    Synthesis 2023年11月7日  査読有り責任著者
    Elastin is present in the extracellular matrix of various tissues, most abundantly in the aorta and major vascular vessels, and is formed by self-assembly followed by concomitant crosslinkers of tropoelastin, an elastin precursor. Desmosine is a pyridinium-based tetrafunctional amino acid that serves as an important crosslinker to bind the polymeric chains of peptides in the 3D network of elastin. Despite its significance, the detailed structure of elastin has not been elucidated. In this work, we report the synthesis of a cyclic desmosine peptide designed to mimic elastin, which could serve as a compound for mass spectrometric analysis to elucidate crosslinking structures. The synthesis involved stepwise and regioselective palladium-catalyzed cross-couplings, and inter- and intramolecular condensations.
  • Tomoyuki Kojima, Takashi Nakamura, Junichi Saito, Yuko Hidaka, Taisuke Akimoto, Hana Inoue, Christian Nanga Chick, Toyonobu Usuki, Makoto Kaneko, Etsuko Miyagi, Yoshihiro Ishikawa, Utako Yokoyama
    Acta Biomaterialia 171 209-222 2023年11月  査読有り
  • Ryosuke Shigeta, Seiya Miyagi, Toyonobu Usuki
    Tetrahedron Letters 132 154805-154805 2023年11月  査読有り責任著者
  • Lokadi Pierre Luhata, Moena Hirao, Natsuki Mori, Toyonobu Usuki
    90 12-16 2023年7月  最終著者責任著者
  • Christian Nanga Chick, Yusuke Sasaki, Mari Kawaguchi, Eri Tanaka, Takako Niikura, Toyonobu Usuki
    Bioorganic & Medicinal Chemistry 90 117351-117351 2023年7月  査読有り責任著者
  • Kaho Oishi, Natsuki Mori, Riki Anzawa, Toyonobu Usuki
    Archives of biochemistry and biophysics 740 109585-109585 2023年5月15日  査読有り責任著者
    Elastin is an important extracellular matrix protein that contributes to the elasticity of cells, tissues, and organs. Although crosslinking amino acids such as desmosine and isodesmosine have been identified in elastin, details regarding the structure remain unclear. In this study, an elastin crosslinker, lysinonorleucine, was chemically synthesized and detected in hydrolyzed bovine ligament and eggshell membrane samples utilizing tandem mass spectrometry. Merodesmosine, another crosslinker of elastin, was also measured in the same samples using the same analytical method. The resulting data should aid in the elucidating the crosslinking structure of elastin and eggshell membranes.
  • Hiroaki Tanaka, Toyonobu Usuki
    HETEROCYCLES 106(7) 2023年5月  査読有り責任著者
  • Lokadi Pierre Luhata, Zixin Deng, Eri Tanaka, Toyonobu Usuki
    Journal of oleo science 72(5) 571-576 2023年4月28日  査読有り責任著者
    An ethyl acetate leaf extract from Odontonema strictum has been reported to have potent antihypertensive activity by inhibiting coronary artery contractions in porcine heart. However, the phytochemistry of the active fraction was unknown. Here we report, for the first time, the isolation and characterization of four known α-pyrones from the active fraction. The antioxidant activity of umuravumbolide (IC50 = 55.7±0.027 µg/mL), deacetylumuravumbolide (IC50 = 0.24±0.0002 µg/mL), dideacetylboronolide (IC50 = 149±0 µg/mL) and deacetylboronolide (IC50 = 24±0 µg/mL) was evaluated in vitro against 2,2-diphenyl-1-picrylhydrazyl radicals. Ascorbic acid was used as a positive control (IC50 = 1.73×10-3±0.3 µg/mL). The presence of 6-substituted 5,6-dihydro-α-pyrones and phenylpropanoid glucosides in the active fraction was suggested to be responsible for the antihypertensive activity. This is the first time that the antioxidant potential of these phytochemicals has been evaluated, and the results indicate that O. strictum has potential as an herbal medicine. Thus, further chemotaxonomic studies among the genera Odontonema and Tetradenia, a known source of α-pyrones, are recommended.
  • Christian Nanga Chick, Tomoo Inoue, Natsuki Mori, Eri Tanaka, Mari Kawaguchi, Toshiyuki Takahashi, Junya Hanakita, Manabu Minami, Ryo Kanematsu, Toyonobu Usuki
    Bioorganic & medicinal chemistry 82 117216-117216 2023年3月15日  査読有り責任著者
    Ligamentum flavum (LF) pathologies often lead to severe myelopathy or radiculopathy characterized by reduced elasticity, obvious thickening, or worsened ossification. Elastin endows critical mechanical properties to tissues and organs such as vertebrae and ligaments. Desmosine (DES) and isodesmosine (IDES) are crosslinkers of elastin monomers called tropoelastin. These crosslinkers are potential biomarkers of chronic obstructive pulmonary disease. As a biological diagnostic tool that supplements existing symptomatic, magnetic resonance imaging scanning or radiological imaging diagnostic measures for LF hypertrophy and associated pathologies, an isotope-dilution liquid chromatography-tandem mass spectrometry method with selected reaction monitoring mode for the quantitation of DESs in human plasma, urine, cerebrospinal fluid (CSF), and yellow ligamentum was investigated. Isotopically labeled IDES-13C3,15N1 was used as an internal standard (ISTD) for DES quantitation for the first time. The samples plus ISTD were hydrolyzed with 6 N hydrochloric acid. Analytes and ISTD were extracted using a solid phase extraction cellulose cartridge column. The assays were repeatable, reproducible, and accurate with % CV ≤ 7.7, ISTD area % RSD of 7.6, and % AC ≤ (101.2 ± 3.90) of the calibrations. The ligamentum samples gave the highest average DES/IDES content (2.38 μg/mg) on a dry-weight basis. A high percentage of the CSF samples showed almost no DESs. Urine and plasma samples of patients showed no significant difference from the control (p-value = 0.0519 and 0.5707, respectively). Microscopy of the yellow ligamentum samples revealed dark or blue-colored zones of elastin fibers that retained the hematoxylin dye and highly red-colored zones of collagen after counterstaining with van Gieson solution. Thus, we successfully developed a method for DES/IDES quantitation in clinical samples.
  • 臼杵豊展
    有機合成化学協会誌 81(3) 213-219 2023年3月1日  責任著者
  • Riki Anzawa, Eri Shiratsuchi, Kenji Miyanari, Christian Nanga Chick, Ayame Mikagi, Michio Yamada, Toyonobu Usuki
    249(3) 829-834 2022年12月1日  査読有り責任著者
  • Akane Yamagishi, Yuki Egoshi, Makoto T. Fujiwara, Noriyuki Suzuki, Tohru Taniguchi, Ryuuichi D. Itoh, Yumiko Suzuki, Yoshiro Masuyama, Kenji Monde, Toyonobu Usuki
    Chemistry – A European Journal 2022年11月10日  査読有り責任著者
  • Ayame Mikagi, Ryosuke Tashiro, Tomoo Inoue, Riki Anzawa, Akiho Imura, Takahiro Tanigawa, Tomohisa Ishida, Takashi Inoue, Kuniyasu Niizuma, Teiji Tominaga, Toyonobu Usuki
    RSC advances 12(49) 31769-31777 2022年11月3日  査読有り責任著者
    Utilizing chemically synthesized an isotopically labeled internal standard, isodesmosine-13C3,15N1, an isotope-dilution LC-MS/MS method was established. Concentrations of desmosine and isodesmosine in plasma of acute cerebral stroke patients and healthy controls were determined. The concentration of desmosines was markedly higher in plasma from acute stroke patients compared with healthy controls. Desmosines are thus novel biomarkers for evaluating the extent of vascular injury after acute cerebral stroke.
  • Tamao Saito, Tomoyuki Iijima, Kohei Koyama, Tomonori Shinagawa, Ayaka Yamanaka, Tsuyoshi Araki, Noriyuki Suzuki, Toyonobu Usuki, Robert R. Kay
    Proceedings of the Royal Society B: Biological Sciences 289(1983) 2022年9月28日  査読有り
    The soil is a rich ecosystem where many ecological interactions are mediated by small molecules, and in which amoebae are low-level predators and also prey. The social amoeba Dictyostelium discoideum has a high genomic potential for producing polyketides to mediate its ecological interactions, including the unique ‘Steely’ enzymes, consisting of a fusion between a fatty acid synthase and a chalcone synthase. We report here that D. discoideum further increases its polyketide potential by using the StlB Steely enzyme, and a downstream chlorinating enzyme, to make both a chlorinated signal molecule, DIF-1, during its multi-cellular development, and a set of abundant polyketides in terminally differentiated stalk cells. We identify one of these as a chlorinated dibenzofuran with potent anti-bacterial activity. To do this, StlB switches expression from prespore to stalk cells in late development and is cleaved to release the chalcone synthase domain. Expression of this domain alone in StlB null cells allows synthesis of the stalk-associated, chlorinated polyketides. Thus, by altered expression and processing of StlB, cells make first a signal molecule, and then abundant secondary metabolites, which we speculate help to protect the mature spores from bacterial infection.
  • Kogaku Kimura, Toyonobu Usuki
    Tetrahedron Letters 107 154102-154102 2022年9月  査読有り責任著者
  • Kaho Oishi, Nao Tanaka, Toyonobu Usuki
    Tetrahedron Letters 107 154106-154106 2022年9月  最終著者責任著者
  • Hiroaki Tanaka, Seiya Miyagi, Yusuke Yoshida, Justin Steven Lamb, Christian Nanga Chick, Lokadi Pierre Luhata, Mizuho Shibata, Eri Tanaka, Yumiko Suzuki, Toyonobu Usuki
    ChemistrySelect 7(30) 2022年8月12日  査読有り最終著者責任著者
  • Lokadi Pierre Luhata, Christian Nanga Chick, Natsuki Mori, Kunihito Tanaka, Hiroshi Uchida, Takashi Hayashita, Toyonobu Usuki
    Molecules (Basel, Switzerland) 27(10) 2022年5月17日  査読有り責任著者
    The aqueous extract of the leaves of Odontonema strictum (OSM) is used in folk medicine for its antihypertensive properties, and it contains a wide range of secondary metabolites, mostly polyphenols such as verbascoside and isoverbascoside, which could play a major role in the preparation of silver nanoparticles. In this study, we aimed to prepare AgNPs for the first time using the OSM leaf extract (OSM-AgNPs) to investigate their free radical-scavenging potency against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2). Dynamic light scattering (DLS), UV/Vis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS) were used to characterize the OSM-AgNPs. With a size around 100 nm and a ζ-potential of -41.1 mV, OSM-AgNPs showed a good stability and a better colloidal property due to electrostatic repulsion and the dispersity. The strong absorption peak at 3 keV in the EDX spectra indicated that silver was the major constituent. Additionally, the existence of silver atoms was confirmed by the Ag 3d5/2 peak around 367 eV in the XPS spectra. IC50 values of 116 μg/mL and 4.4 μg/mL were obtained for the scavenging activities of DPPH and H2O2, respectively. The synthetic OSM-AgNPs can be further exploited as potential antioxidant agents.
  • Natsuki Mori, Toyonobu Usuki
    Phytochemical analysis : PCA 2022年5月12日  査読有り責任著者
    INTRODUCTION: The essential oils of tea tree (Melaleuca alternifolia) leaves mainly contain eucalyptol, α-terpinene, γ $$ \gamma $$ -terpinene, and terpinen-4-ol and have anti-bacterial, anti-fungal, anti-infective, and anti-inflammatory actions. The essential oils of lemon grass (Cymbopogon citratus) leaves mainly contain neral, geranial, and geraniol and have anti-microbial and anti-fungal activities and hypocholesterolemic effect. OBJECTIVES: The present study describes the use of low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for efficient extraction of essential oils from tea tree and lemon grass. H2 O and EtOH were used for extraction as control methods. METHODOLOGY: Quantitative analysis was performed using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring mode. Scanning electron micrography (SEM) and antioxidant assays for extracted samples were also conducted. RESULTS: The results indicated that extraction for tea tree using betaine/sucrose (molar ratio 2:1) improved the yields of terpinolene and eucalyptol 2.5- and 1.9-fold, respectively, compared with the control method. In lemon grass, extraction using betaine/sucrose (molar ratio 2:1) improved the yields of neral and geranial 1.9- and 1.7-fold, respectively, compared with the control method. CONCLUSION: These results demonstrated the effective extraction of essential oils from plant leaves under milder conditions than those needed for the conventional methods. The environmentally benign DESs for the extraction would be applicable to the food and cosmetic industries.
  • Seiya Miyagi, Reiko Yokoo, Takahiro Tanigawa, Dinda B. Pitna, Mika Hirose, Toyonobu Usuki
    Tetrahedron Letters 90 153616-153616 2022年2月  査読有り責任著者
  • Lokadi Pierre Luhata, Toyonobu Usuki
    Bioorganic & medicinal chemistry letters 59 128528-128528 2022年1月6日  査読有り責任著者
    The aqueous extract of the leaves of Odontonema strictum, a plant from tropical regions, is used by traditional physicians in Burkina Faso for its antihypertensive properties. Verbascoside and isoverbascoside, known phenylpropanoid glycosides with high solubility in water, have been isolated from the leaves. We evaluated their antioxidant properties in vitro by radical scavenging using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide (H2O2). Verbascoside and isoverbascoside demonstrated high levels of DPPH radical scavenging activity, with IC50 values of 0.09±0.03 μg/mL and 0.16±0.07 μg/mL, respectively, compared to 0.05±0.0 μg/mL for ascorbic acid as a control. These two phenylpropanoid glycosides were also more potent (2.6±0.36 μg/mL and 3.0±0.01 μg/mL) in scavenging H2O2 than the ascorbic acid control (4.1±0.97 µg/mL). This is the first time that the antioxidant properties of verbascoside and isoverbascoside from O. strictum have been evaluated. These results can explain the use of this plant for hypertension in folk medicine.
  • Toyonobu Usuki, Takahiro Suzuki, Nao Tanaka, Hiroaki Tanaka
    HETEROCYCLES 104(5) 961-961 2022年  最終著者責任著者
  • Mika Hirose, Toyoaki Kobayashi, Nao Tanaka, Ayame Mikagi, Hiroshi Wachi, Yuki Mizutani, Toyonobu Usuki
    Bioorganic & medicinal chemistry 52 116519-116519 2021年12月15日  査読有り責任著者
    Desmosine and isodesmosine are crosslinking amino acids of elastin, which is an essential component of the dermal extracellular matrix protein. Quantitative analysis of crosslinker desmosines in human skin dermis has not been fully achieved due to the insoluble nature of elastin protein. In the present study, chemical synthesis of isotopically labeled desmosine, desmosine-13C3,15N1, was carried out via isoChichibabin pyridinium synthesis starting from corresponding isotopically labeled amino acids. Isotope-dilution LC-MS/MS analysis of desmosine and isodesmosine utilizing synthetic desmosine-13C3,15N1 enabled the quantitative analysis of desmosines in human skin for the first time. Thus, ca. 1.43 μg of desmosines was detected from analysis of 1 mg of dry human skin.
  • Mika Hirose, Nao Tanaka, Toyonobu Usuki
    Bioorganic & medicinal chemistry letters 46 128165-128165 2021年8月15日  最終著者責任著者
    Ma'edamines C and D were isolated from an Okinawan marine sponge and exhibited a unique tetrasubstituted pyridinium skeleton. The proposed biosynthetic pathway is similar to that of desmosine and isodesmosine, which are elastin-crosslinking amino acids. In this study, first total synthesis of ma'edamines C and D was achieved via Pr(OTf)3-promoted Chichibabin/isoChichibabin pyridinium synthesis starting from the corresponding aldehydes and amine.
  • Rina Yasutomi, Riki Anzawa, Masamitsu Urakawa, Toyonobu Usuki
    Molecules 26(14) 4271-4271 2021年7月14日  査読有り招待有り責任著者
    The essential oils of hinoki (Chamaecyparis obtusa) leaves have anti-bacterial, anti-fungal, and relaxation properties that are likely associated with the major components such as sabinene, α-terpinyl acetate, limonene, elemol, myrcene, and hibaene. The present study describes the use of a cellulose-dissolving ionic liquid (IL) [C2mim][(MeO)(H)PO2] and low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for the efficient extraction of hinoki essential oils. As a control method, organic solvent extraction was performed using either hexane, ethyl acetate (EtOAc), or acetone at 30 °C for 1 h. Both the experimental and control methods were conducted under the same conditions, which relied on partial dissolution of the leaves using the IL and DESs before partitioning the hinoki oils into the organic solvent for analysis. Quantitative analysis was performed using gas chromatography–mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The results indicated that extraction using the [C2mim][(MeO)(H)PO2]/acetone bilayer system improved the yields of limonene and hibaene, 1.5- and 1.9-fold, respectively, when compared with the control method. In addition, extraction using betaine/l-lactic acid (molar ratio 1:1) gave the greatest yields for both limonene and hibaene, 1.3-fold and 1.5-fold greater, respectively, than when using an organic solvent. These results demonstrate the effective extraction of essential oils from plant leaves under conditions milder than those needed for the conventional method. The less toxic and environmentally begin DESs for the extraction are also applicable to the food and cosmetic industries.
  • Dinda B. Pitna, Nao Tanaka, Toyonobu Usuki
    Journal of Heterocyclic Chemistry 2021年7月9日  査読有り責任著者
  • Lokadi Pierre Luhata, Toyonobu Usuki
    Bioorganic & medicinal chemistry letters 48 128248-128248 2021年7月9日  査読有り責任著者
    The observation of a dog eating the roots of Odontonema strictum in 2008 in Lubumbashi (DR. Congo) was the starting point of this research which later led to the isolation of β-sitosterol (BSL), a known phytosterol, isolated for the first time from the leaves of this tropical plant which has a large range of medicinal properties including anti-inflammation, anti-hypertension and antibacterial. The analysis of the 1H NMR spectrum showed that the active compound contains 60% of BSL and 40% of stigmasterol. With a melting point (m.p.) of 134-136 °C and the Rf value 0.55 in EtOAc-hexane (1:3) on silica gel TLC, the active compound was confirmed to be BSL. Here, we determined the minimal inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of BSL on Staphylococcus aureus by the broth dilution method. The MIC and MBC were found to be 1.24 mg/mL and 2.208 mg/mL, respectively. For the crude extract, the MIC and MBC were 4.33 mg/mL and the MBC was 7.66 mg/mL, respectively. The Total antibacterial activity underlined the fact that the crude extract from 1 g of plant materials could be diluted 65 times and still retains the ability to inhibit the growth of S. aureus. This is the first report of the antibacterial activity of BSL from this plant.
  • Tenma Nakamura, Dinda B. Pitna, Kogaku Kimura, Yukiko Yoshimoto, Tomoya Uchiyama, Takaya Mori, Ryosuke Kondo, Shihori Hara, Yuki Egoshi, Shoya Yamaguchi, Noriyuki Suzuki, Yumiko Suzuki, Toyonobu Usuki
    Organic & Biomolecular Chemistry 19(27) 6038-6044 2021年4月30日  査読有り責任著者
    <p>Cynaropicrin is found in artichoke (<italic>Cynara scolymus</italic>) and is the source of its bitter taste and is a sesquiterpene lactone with a 5-7-5 tricyclic skeleton, six chiral centers, and four...</p>
  • Yuki Mizukawa, Mayumi Ikegami-Kawai, Masako Horiuchi, Marcel Kaiser, Masayoshi Kojima, Seiki Sakanoue, Seiya Miyagi, Christian Nanga Chick, Hiroyuki Togashi, Masayoshi Tsubuki, Masataka Ihara, Toyonobu Usuki, Isamu Itoh
    Bioorganic & Medicinal Chemistry 33 116018-116018 2021年3月  査読有り
  • Natsima Viriyaadhammaa, Aroonchai Saiai, Waranya Neimkhum, Wariya Nirachonkul, Wantida Chaiyana, Sawitree Chiampanichayakul, Singkome Tima, Toyonobu Usuki, Suwit Duangmano, Songyot Anuchapreeda
    Molecules 25(22) 5476-5476 2020年11月23日  査読有り
  • Aisya Syahmina, Toyonobu Usuki
    ACS Omega 5(45) 29618-29622 2020年11月17日  査読有り責任著者
  • Christian Nanga Chick, Tomoyo Misawa-Suzuki, Yumiko Suzuki, Toyonobu Usuki
    Bioorganic & Medicinal Chemistry Letters 30(22) 127526-127526 2020年11月  査読有り責任著者
  • Nao Tanaka, Toyonobu Usuki
    European Journal of Organic Chemistry 2020(34) 5514-5522 2020年9月14日  査読有り責任著者
  • Songyot Anuchapreeda, Riki Anzawa, Natsima Viriyaadhammaa, Waranya Neimkhum, Wantida Chaiyana, Siriporn Okonogi, Toyonobu Usuki
    Bioorganic & Medicinal Chemistry Letters 30(14) 127256-127256 2020年7月  査読有り責任著者
  • Mika Hirose, Reiko Yokoo, Daisuke Watanabe, Rina Suzuki, Miho Tanigawa, Toyonobu Usuki
    ChemistrySelect 5(13) 3843-3846 2020年4月7日  査読有り責任著者
  • Daria A. Baut, Nao Tanaka, Reiko Yokoo, Toyonobu Usuki
    Chirality 32 431-436 2020年4月  査読有り招待有り
  • Songyot Anuchapreeda, Fah Chueahongthong, Natsima Viriyaadhammaa, Pawaret Panyajai, Riki Anzawa, Singkome Tima, Chadarat Ampasavate, Aroonchai Saiai, Methee Rungrojsakul, Toyonobu Usuki, Siriporn Okonogi
    25(6) 1300-1300 2020年3月12日  査読有り責任著者
  • Toyonobu Usuki, Yukiko Yoshimoto, Makiko Sato, Tae Takenaka, Ryota Takezawa, Yusuke Yoshida, Masayuki Satake, Noriyuki Suzuki, Daisuke Hashizume, Sergei V. Dzyuba
    Bioorganic and Medicinal Chemistry 28(2) 2020年1月15日  査読有り責任著者
    Ginkgo biloba extracts have been postulated to beneficial for improving cognitive function and as such they have been used as a potential treatment of Alzheimer's disease. The main active ingredients of the extract are terpene trilactones (TTLs), such as bilobalide (BB) and ginkgolides. Several structure–activity relationship (SAR) studies using ginkgolide scaffolds produced more biologically potent species by modification of the lactone moieties. However, modifications of BB scaffold have been limited, and no SAR studies on BB have been accomplished to date. Thus, the aim of this study was to elucidate how the modification of the lactone moieties of BB would affect their biological activities in a number of assays, including proliferating cell activity, neuroprotective effects against Aβ (1–40) peptides, and neurite outgrowth effects in PC12 neuronal cells. It appeared that the derivatives containing lactone groups showed similar biological activity to native BB, while those that possessed no lactone moieties exhibited lower neurite outgrowth effects. Thus, the results suggested that the lactone moieties of BB played an important role in exerting neurite outgrowth effects in PC12 cells.
  • Nao Tanaka, Toyonobu Usuki
    Natural Product Communications 14(1934578X19849967) 1934578X1984996-1934578X1984996 2019年6月6日  査読有り責任著者
  • Jing Li, Yusuke Yoshida, Manami Kurita, Toyonobu Usuki
    Bioorganic & Medicinal Chemistry Letters 29(12) 1518-1521 2019年6月  査読有り責任著者
  • Hitomi Mizuno, Hibiki Yoshikawa, Toyonobu Usuki
    Natural Product Communications 14(1934578X19845816) 2019年5月17日  査読有り責任著者
  • Quang Thuong Tran, Loan Thi, Thanh Vu, Tram Huyen Le, Ly Thi Phuong Giang, Toyonobu Usuki
    Asian Journal of Chemistry 31(5) 1045-1048 2019年3月28日  査読有り責任著者

MISC

 2

書籍等出版物

 2

講演・口頭発表等

 281

共同研究・競争的資金等の研究課題

 22

その他

 7