Details of a Researcher - Toshima, Kazunobu

Papers - Toshima, Kazunobu

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Designed Mannosylerythritol Lipid Analogues Exhibiting both Selective Cytotoxicity against Human Skin Cancer Cells and Recovery Effects on Damaged Skin Cells

Jikun Meng, Chihiro Yasui, Mai Shida, Kazunobu Toshima, *DAISUKE TAKAHASHI

Chemistry A European Journal 2024.05

Research paper (scientific journal), Corresponding author, Accepted

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Photo-Induced Glycosylation Using the Edible Polyphenol Curcumin

Satomi Goi, Hidenari Shigeta, DAISUKE TAKAHASHI, *Kazunobu Toshima

(Organic & Biomolecular Chemistry ) 2024.05

Last author, Corresponding author, Accepted

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Discovery of a Novel Photosensitizer Based on the Enediyne Antibiotic N1999A2 and Its Application as a Glutathione-Activatable Theranostic Agent

Kotono Matsunaga, Minami Takahashi, Tugumi Kagaya, DAISUKE TAKAHASHI, *Kazunobu Toshima

Bulletin of the Chemical Society of Japan 97卷 ( 5号 ) uoae057頁 2024.05

Research paper (scientific journal), Last author, Corresponding author, Accepted

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Synthesis and Immunological Evaluation of Escherichia coli O1- Derived Oligosaccharide–Protein Conjugates toward Avian Pathogenic Escherichia coli O1 Vaccine Development

Katsunori Seki, Takumi Makikawa, *Kazunobu Toshima, *DAISUKE TAKAHASHI

Synthesis (Georg Thieme Verlag KG ) 56巻 ( 06号 ) 953頁 - 965頁 2023.08

Research paper (scientific journal), Joint Work, Corresponding author, Accepted, ISSN 0039-7881

Abstract
Avian pathogenic Escherichia coli O1 (APEC O1) is a pathogenic bacterium that causes significant economic losses in the poultry industry and raises concerns about zoonotic infections. The development of effective vaccines against APEC O1 is essential due to antibiotic resistance and the potential for severe symptoms in both chickens and humans. In this context, we have been focusing on the O1A, O1B, and O1C antigen structures derived from E. coli O1 lipopolysaccharide (LPS). In this study, the first synthesis of the pentasaccharide repeating units of the O1B and O1C antigens was successfully achieved. The synthesis and immunological evaluation of their conjugates with bovine serum albumin (BSA) were conducted. Only the O1A-pentasaccharide structure is a glycotope candidate for APEC O1. Keyhole limpet hemocyanin (KLH)–O1A-pentasaccharide conjugate was also synthesized, and its immunogenicity was evaluated by the ELISA assay. The efficient production of antibodies capable of binding to both APEC O1 LPS and the O1A-pentasaccharide structure was observed, indicating that O1A-pentasaccharide is a promising vaccine candidate against APEC O1.

Regioselective and Stereospecific β‐Arabinofuranosylation by Boron‐Mediated Aglycon Delivery

Kazuki Inaba, Yuna Naito, Mina Tachibana, *Kazunobu Toshima, *DAISUKE TAKAHASHI

ANGEWANDTE CHEMIE - INTERNATIONAL EDITION (Wiley ) 2023.07

Joint Work, Corresponding author, Accepted, ISSN 14337851

Regio- and stereoselective formation of the 1,2-cis-furanosidic linkage has been in great demand for efficient synthesis of biologically active natural glycosides. In this study, we developed a regioselective and β-stereospecific d-/l-arabinofuranosylation promoted by a boronic acid catalyst under mild conditions. The glycosylations proceeded smoothly for a variety of diols, triols, and unprotected sugar acceptors to give the corresponding β-arabinofuranosides (β-Arbf) in high yields with complete β-stereoselectivity and high regioselectivity. The regioselectivity was completely reversed depending on the optical isomerism of the donor used and was predictable a priori using predictive models. Mechanistic studies based on DFT calculations revealed that the present glycosylation occurs through a highly dissociative concerted SNi mechanism. The usefulness of the glycosylation method was demonstrated by the chemical synthesis of trisaccharide structures of arabinogalactan fragments.

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Photoinduced Glycosylation Using a Diarylthiophene as an Organo Lewis Photoacid Catalyst

Naoki Otani, Kohei Higashiyama, Hayato Sakai, Taku Hasobe, *DAISUKE TAKAHASHI, *Kazunobu Toshima

European Journal of Organic Chemistry (Wiley) 26巻 2023.04

Research paper (scientific journal), Last author, Corresponding author, Accepted, ISSN 1434193X

Here reports an photoinduced glycosylation of trichloroacetimidate donors and several alcohols using 3,11-dimethoxydinaphthothiophene as an organo Lewis photoacid catalyst upon long-wavelength UV-LED light (385 nm) irradiation. The reaction proceeded under mild reaction conditions smoothly to give the corresponding glycosides in good to high yields. In addition, the present glycosylation method was applicable to a wide range of trichloroacetimidate donors and acceptors. Furthermore, the dinaphthothiophene catalyst could be recovered and reused without any loss of efficiency. Moreover, this glycosylation method was applied successfully to the total synthesis of a biologically active natural product, cholesteryl 6-O-myristoyl-α-glucoside.

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Destabilization of vitelline membrane outer layer protein 1 homolog (VMO1) by <i>C</i> ‐mannosylation

Satoshi Yoshimoto, Takehiro Suzuki, Naoki Otani, DAISUKE TAKAHASHI, Kazunobu Toshima, Naoshi Dohmae, Siro Simizu

FEBS Open Bio (Wiley) 13 ( 3 ) 490 - 499 2023.01

Accepted, ISSN 2211-5463

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Photoinduced Glycosylation Using a Diarylthiophene as an Organo Lewis Photoacid Catalyst

Naoki Otani, Kohei Higashiyama, Hayato Sakai, Taku Hasobe, *DAISUKE TAKAHASHI, *Kazunobu Toshima

European Journal of Organic Chemistry (Wiley) 2023

Last author, Corresponding author, Accepted, ISSN 1434193X

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Synthesis of Mannosylerythritol Lipid Analogues and their Self-Assembling Properties, Recovery Effects on Damaged Skin Cells, and Antibacterial Activity.

Takanori Kondo, Chihiro Yasui, Ikkei Miyajima, Taisuke Banno, Kouichi Asakura, Tokuma Fukuoka, Kazunori Ushimaru, Maito Koga, Azusa Saika, Tomotake Morita, Yoshiaki Takahashi, Chigusa Hayashi, Masayuki Igarashi, *DAISUKE TAKAHASHI, *Kazunobu Toshima

CHEMISTRY-A EUROPEAN JOURNAL (Chemistry - A European Journal) 28 ( 55 ) 2022.10

Last author, Corresponding author, Accepted, ISSN 09476539

Synthesis of three types of purpose-designed mannosylerythritol lipid (MEL)-D analogues with decanoyl groups (C10), β-GlcEL-D, α-GlcEL-D, and α-MEL-D, was accomplished utilizing our boron-mediated aglycon delivery (BMAD) methods. Their self-assembling properties, recovery effects on damaged skin cells, and antibacterial activity were evaluated. It was revealed, for the first time, that α-GlcEL-D and α-MEL-D only generated giant vesicles, indicating that slight differences in the steric configuration of an erythritol moiety and fatty acyl chains affect the ability to form vesicles. Analogue α-MEL-D exhibited significant recovery effects on damaged skin cells. Furthermore, α-MEL-D exhibited antibacterial activity as high as that for MEL-D, indicating that α-MEL-D is a promising artificial sugar-based material candidate for enhancing the barrier function of the stratum corneum, superior to a known cosmetic ingredient, and possesses antibacterial activity.

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Efficient Strategy for the Preparation of Chemical Probes of Biologically Active Glycosides Using a Boron-Mediated Aglycon Delivery (BMAD) Method

Kosuke Kimura, Takeshi Yasunaga, Takumi Makikawa, *DAISUKE TAKAHASHI, *Kazunobu Toshima

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN (The Chemical Society of Japan) 95 ( ７ ) 1075 - 1082 2022.07

Accepted, ISSN 00092673

Development of an efficient method for the analysis and identification of the target proteins with which biologically active glycosides directly interact is highly desirable in many research fields. In this article, we report an efficient strategy for the preparation of chemical probes of biologically active glycosides using a reaction sequence of i) a boron-mediated aglycon delivery (BMAD) with an N3-functionalized 1,2-anhydroglu-cose donor, ii) deprotection, and iii) strain-promoted azidealkyne cycloaddition. Using the synthesized chemical probes, we successfully demonstrated that the target proteins of a cardiac glycoside, lanatoside C (1), can be visualized and identified in human colon cancer HCT116 cells.

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Self-Assembling Properties and Recovery Effects on Damaged Skin Cells of Chemically Synthesized Mannosylerythritol Lipids.

Takanori Kondo, Chihiro Yasui, Taisuke Banno, Kouichi Asakura, Tokuma Fukuoka, Kazunori Ushimaru, Maito Koga, Hiroyuki Minamikawa, Azusa Saika, Tomotake Morita, Daisuke Takahashi, Kazunobu Toshima

Chembiochem : a European journal of chemical biology (ChemBioChem) 23 ( 2 ) e202100631 2022.01

Last author, Corresponding author, Accepted, ISSN 14394227

Mannosylerythritol lipids (MELs), which are one of the representative sugar-based biosurfactants (BSs) produced by microorganisms, have attracted much attention in various fields in the sustainable development goals (SDGs) era. However, they are inseparable mixtures with respect to the chain length of the fatty acids. In this study, self-assembling properties and structure-activity relationship (SAR) studies of recovery effects on damaged skin cells using chemically synthesized MELs were investigated. It was revealed, for the first time, that synthetic and homogeneous MELs exhibited significant self-assembling properties to form droplets or giant vesicles. In addition, a small difference in the length of the fatty acid chains of the MELs significantly affected their recovery effects on the damaged skin cells. MELs with medium or longer length alkyl chains exhibited much higher recovery effects than that of C18-ceramide NP.

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Hypocrellin B-based activatable photosensitizers for specific photodynamic effects against high H2O2-expressing cancer cells.

Takashi Kitamura, Hirotaka Nakata, Daisuke Takahashi, Kazunobu Toshima

Chemical communications (Cambridge, England) (Chemical Communications) 58 ( 2 ) 242 - 245 2022.01

Last author, Corresponding author, Accepted, ISSN 13597345

A novel tumor-related biomarker, a H2O2-activatable photosensitizer 4 based on the 1,3-dicarbonyl enol moieties of hypocrellin B (3), was designed and synthesized. The photosensitizer 4 showed a blue-shifted absorption band compared with 3, and showed negligible photosensitizing ability without H2O2. However, the release of 3 from 4 by the reaction with H2O2 regenerated the photosensitizing ability. Furthermore, 4 exhibited selective and effective photo-cytotoxicity against high H2O2-expressing cancer cells upon photo-irradiation with 660 nm light, which is inside the phototherapeutic window.

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Synthesis of low-molecular weight fucoidan derivatives and their binding abilities to SARS-CoV-2 spike proteins

Tatsuki Koike, Aoi Sugimoto, Shuhei Kosono, Sumika Komaba, Yuko Kanno, Takashi Kitamura, Itsuki Anzai, Tokiko Watanabe, Daisuke Takahashi, Kazunobu Toshima

RSC Medicinal Chemistry (Royal Society of Chemistry (RSC)) 12 ( 12 ) 2016 - 2021 2021.12

Last author, Corresponding author, Accepted, ISSN 26328682

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Synthesis of a Pentasaccharide Repeating Unit of Lipopolysaccharide Derived from Virulent E. coli O1 and Identification of a Glycotope Candidate of Avian Pathogenic E. coli O1

Nobuya Nishi, Katsunori Seki, *Daisuke Takahashi, *Kazunobu Toshima

Angewandte Chemie - International Edition (Angewandte Chemie - International Edition) 60 ( 4 ) 1789 - 1796 2021.01

Research paper (scientific journal), Accepted, ISSN 14337851

© 2020 Wiley-VCH GmbH Avian pathogenic Escherichia coli (APEC) is a common bacterial pathogen infecting chickens, resulting in economic losses to the poultry industry worldwide. In particular, APEC O1, one of the most common serotypes of APEC, is considered problematic due to its zoonotic potential. Therefore, many attempts have been made to develop an effective vaccine against APEC O1. In fact, the lipopolysaccharide (LPS) O-antigen of APEC O1 has been shown to be a potent antigen for inducing specific protective immune responses. However, the detailed structure of the O-antigen of APEC O1 is not clear. The present study demonstrates the first synthesis of a pentasaccharide repeating unit of LPS derived from virulent E. coli O1 and its conjugate with BSA. ELISA tests using the semi-synthetic glycoconjugate and the APEC O1 immune chicken serum revealed that the pentasaccharide is a glycotope candidate of APEC O1, with great potential as an antigen for vaccine development.

This paper was press-released from Keio University. (https://www.keio.ac.jp/ja/press-releases/2020/11/16/28-76321/)
This paper was selected as a Hot Paper.
This paper was selected as an inside back cover.

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Diboron-Catalyzed Regio- and 1,2-cis-α-Stereoselective Glycosylation of trans-1,2-Diols.

Shunpei Tomita, Masamichi Tanaka, Michitaka Inoue, Kazuki Inaba, *Daisuke Takahashi, *Kazunobu Toshima

THE JOURNAL OF ORGANIC CHEMISTRY (American Chemical Society) 85 ( 24 ) 16254 - 16262 2020.12

Research paper (scientific journal), Joint Work, Accepted

Regio- and 1,2-cis-α-stereoselective glycosylations were investigated using 1,2-anhydroglucose donors and trans-1,2-diol sugar acceptors in the presence of a diboron catalyst. The reactions proceeded smoothly to provide the corresponding 1,2-cis-α-glycosides with consistently very high stereoselectivity and were regioselectivity controlled by the protecting groups of the acceptor. The present glycosylation method was applied successfully to the efficient synthesis of α-1,3-glucan pentasaccharide.

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2-Naphthol Moiety of Neocarzinostatin Chromophore as a Novel Protein-Photodegrading Agent and Its Application as a H<inf>2</inf>O<inf>2</inf>-Activatable Photosensitizer

Takashi Kitamura, Saori Shiroshita, *Daisuke Takahashi *Kazunobu Toshima

Chemistry - A European Journal (Wiley-VCH ) 26 ( 63 ) 14351 - 14358 2020.11

Research paper (scientific journal), Joint Work, Accepted, ISSN 09476539

© 2020 Wiley-VCH GmbH A 2-naphthol derivative 2 corresponding to the aromatic ring moiety of neocarzinostatin chromophore was found to degrade proteins under photo-irradiation with long-wavelength UV light without any additives under neutral conditions. Structure–activity relationship studies of the derivative revealed that methylation of the hydroxyl group at the C2 position of 2 significantly suppressed its photodegradation ability. Furthermore, a purpose-designed synthetic tumor-related biomarker, a H2O2-activatable photosensitizer 8 possessing a H2O2-responsive arylboronic ester moiety conjugated to the hydroxyl group at the C2 position of 2, showed significantly lower photodegradation ability compared to 2. However, release of the 2 from 8 by reaction with H2O2 regenerated the photodegradation ability. Compound 8 exhibited selective photo-cytotoxicity against high H2O2-expressing cancer cells upon irradiation with long-wavelength UV light.

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Total Synthesis of Terpioside B

Kazuki Inaba, Masato Endo, Naoto Iibuchi, Daisuke Takahashi, *Kazunobu Toshima

Chemistry - A European Journal (Wiley-VCH ) 26 ( 45 ) 10222 - 10225 2020.08

Research paper (scientific journal), Joint Work, Accepted, ISSN 09476539

© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The first total synthesis of terpioside B (1) has been accomplished. Key steps include the stereoselective installments of a set of challenging 1,2-cis-glycosidic linkages. Thus, α(1,4)-linked d-galactoside was effectively constructed from a 1,2-anhydrogalactose donor and an unprotected 1,6-anhydrogalactose acceptor by using a boron-mediated aglycon delivery (BMAD) method. In addition, α-l-fucofuranosides were stereoselectively and simultaneously constructed by remote group-assisted 1,2-cis-α-stereoselective glycosylations.

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Diastereoselective desymmetric 1,2-cis-glycosylation of meso-diols via chirality transfer from a glycosyl donor

Tanaka M., Sato K., Yoshida R., Nishi N., Oyamada R., Inaba K., *Takahashi D., *Toshima K.

Nature Communications (Springer Nature) 11 ( 1 ) 2431 2020.05

Research paper (scientific journal), Joint Work, Accepted

© 2020, The Author(s). Chemical desymmetrization reactions of meso-diols are highly effective for the precise and efficient synthesis of chiral molecules. However, even though enzyme-catalyzed desymmetric glycosylations are frequently found in nature, there is no method for highly diastereoselective desymmetric chemical glycosylation of meso-diols. Herein, we report a highly diastereoselective desymmetric 1,2-cis-glycosylation of meso-diols found in myo-inositol 1,3,5-orthoesters using a boronic acid catalyst based on predictions of regioselectivity by density functional theory (DFT) calculations. The enantiotopic hydroxyl groups of the meso-diols are clearly differentiated by the stereochemistry at the C2 position of the glycosyl donor with excellent regioselectivities. In addition, the present method is successfully applied to the synthesis of core structures of phosphatidylinositolmannosides (PIMs) and glycosylphosphatidylinositol (GPI) anchors, and common β-mannoside structures of the LLBM-782 series of antibiotics.

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Photo-induced glycosylation using a diaryldisulfide as an organo-Lewis photoacid catalyst

Iibuchi N., Eto T., Aoyagi M., Kurinami R., Sakai H., Hasobe T., *Takahashi D., * Toshima K

Organic and Biomolecular Chemistry (The Royal Society of Chemistry) 18 ( 5 ) 851 - 855 2020.01

Research paper (scientific journal), Joint Work, Accepted, ISSN 14770520

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Total Synthesis and Structure–Activity Relationship Study of Vineomycin A₁

Yuka Matsumoto, Hajime Kuriki, Takashi Kitamura, *Daisuke Takahashi, , *Kazunobu Toshima

THE JOURNAL OF ORGANIC CHEMISTRY 84 ( 22 ) 14724 - 14732 2019.10

Research paper (scientific journal), Joint Work, Accepted

The first total synthesis of vineomycin A1 (1) has been accomplished. Structure–activity relationship studies for cytotoxicity against human breast cancer MCF-7 cells using several synthetic vineomycin A1 analogues differing in the number and position of glycon moieties revealed that the cytotoxicity increased as the number of glycon moieties increased. The position of the glycon moiety was one of the key factors for the cytotoxicity of 1. Moreover, in vitro analysis of the cytotoxicity of 1 against MCF-7 cells indicated for the first time that 1 effectively induced cancer cell death by apoptosis, not by acting as a DNA intercalating agent.

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