Research Achievements - Original paper -

Total synthesis of selaginellin A

K. Fujiwara, T. Itagaki, T. Tokiwano

Tetrahedron Letters ( Tetrahedron Letters )  79   153295   2021.08  [Refereed]

Research paper (journal)   Domestic Co-author

The total synthesis of selaginellin A, isolated from Selaginella tamariscina, was achieved through an eight-step process including a Diels-Alder reaction, formation of a quinone methide moiety and dehydrogenative aromatization. The NMR spectra collected for different samples of synthetic selaginellin A initially showed irregular peak shapes and variable chemical shifts for the signals of the phenol-substituted quinone methide moiety under neutral conditions. After detailed NMR analysis, it was found that the addition of a trace amount of trifluoroacetic acid accelerated the tautomerism of the phenol-substituted quinone methide moiety and improved the reproducibility of the chemical shifts of synthetic selaginellin A.

DOI

4-(2,5-Dimethyl-1H-pyrrol-1-yl)-N-(2,5-dioxopyrrolidin-1-yl) benzamide improves monoclonal antibody production in a Chinese hamster ovary cell culture

Y. Aki, Y. Katsumata, H. Kakihara, K. Nonaka, K. Fujiwara

PLoS ONE ( PLoS ONE )  16 ( 4 April 2021 ) e0250416   2021.04  [Refereed]

Research paper (journal)   Domestic Co-author

There is a continuous demand to improve monoclonal antibody production for medication supply and medical cost reduction. For over 20 years, recombinant Chinese hamster ovary cells have been used as a host in monoclonal antibody production due to robustness, high productivity and ability to produce proteins with ideal glycans. Chemical compounds, such as dimethyl sulfoxide, lithium chloride, and butyric acid, have been shown to improve monoclonal antibody production in mammalian cell cultures. In this study, we aimed to discover new chemical compounds that can improve cell-specific antibody production in recombinant Chinese hamster ovary cells. Out of the 23,227 chemicals screened in this study, 4-(2,5-dimethyl-1H-pyrrol-1-yl)-N-(2,5-dioxopyrrolidin-1-yl) benzamide was found to increase monoclonal antibody production. The compound suppressed cell growth and increased both cell-specific glucose uptake rate and the amount of intracellular adenosine triphosphate during monoclonal antibody production. In addition, the compound also suppressed the galactosylation on a monoclonal antibody, which is a critical quality attribute of therapeutic monoclonal antibodies. Therefore, the compound might also be used to control the level of the galactosylation for the N-linked glycans. Further, the structure-activity relationship study revealed that 2,5-dimethylpyrrole was the most effective partial structure of 4-(2,5-dimethyl-1H-pyrrol-1-yl)-N-(2,5-dioxopyrrolidin-1-yl) benzamide on monoclonal antibody production. Further structural optimization of 2,5-dimethylpyrrole derivatives could lead to improved production and quality control of monoclonal antibodies.

DOI PubMed

Total synthesis of selaginellin S

Kenshu Fujiwara, Takaya Itagaki, Yoshihiko Kondo, Uichi Akiba, Tetsuo Tokiwano

Tetrahedron Letters ( Tetrahedron Letters )  61 ( 25 ) 152031   2020.06  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

An Approach to a 2-Hydroxy-3-phenyldibenzofuran Skeleton Based on Rh(PPh₃)₃Cl-Catalyzed [2+2+2] Cycloaddition Between a 1-Ethynyl-2-(Ethynyloxy)benzene and an (Alkoxyethynyl)benzene

Daisuke Sato, Kenshu Fujiwara, Yoshihiko Kondo, Uichi Akiba, Tetsuo Tokiwano

HETEROCYCLES   101 ( 2 ) 417 - 422   2020.01  [Refereed]

Research paper (journal)   Domestic Co-author

Molecular Wires with Controllable π‐Delocalization Incorporating Redox‐Triggered π‐Conjugated Switching Units.

Wataru Nojo, Hitomi Tamaoki, Yusuke Ishigaki, Ryo Katoono, Kenshu Fujiwara, Takanori Fukushima, Takanori Suzuki

ChemPlusChem   84 ( 6 ) 634 - 642   2019.07  [Refereed]

Research paper (journal)   Domestic Co-author

Total synthesis of kehokorins A and B.

Kenshu Fujiwara, Ryosuke Motousu, Daisuke Sato, Yoshihiko Kondo, Uichi Akiba, Takanori Suzuki, Tetsuo Tokiwano

Tetrahedron Letters   60   1299 - 1301   2019.03  [Refereed]

Research paper (journal)   Domestic Co-author

Synthesis of the cyclohexene segment of portimine.

Takafumi Saito, Kenshu Fujiwara, Yoshihiko Kondo, Uichi Akiba, Takanori Suzuki

Tetrahedron Letters   60   386 - 389   2019.01  [Refereed]

Research paper (journal)   Domestic Co-author

Transmission of Point Chirality to Axial Chirality for Strong Circular Dichroism in Triarylmethylium- o,o -Dimers.

Yusuke Ishigaki, Tomohiro Iwai, Yuki Hayashi, Aiichiro Nagaki, Ryo Katoono, Kenshu Fujiwara, Jun-ichi Yoshida, Takanori Suzuki

Synlett   29 ( 16 ) 2147 - 2154   2018.06  [Refereed]

Research paper (journal)   Domestic Co-author

Enhanced Circular Dichroism at Elevated Temperatures through Complexation-Induced Transformation of a Three-Layer Cyclophane with Dualistic Dynamic Helicity.

Ryo Katoono, Yudai Obara, Kenshu Fujiwara, Takanori Suzuki

Chemical Science   9   2222 - 2229   2018.04  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Supramolecular chiroptical switching of helical-sense preferences through the two-way intramolecular transmission of a single chiral source

R. Katoono, K. Kusaka, Y. Tanaka, K. Fujiwara, T. Suzuki

Organic & Biomolecular Chemistry   16 ( 7 ) 1167 - 1171   2018.03  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

An improved synthesis of the C42-C52 segment of ciguatoxin 3C.

T. Saito, K. Fujiwara, Y. Sano, T. Sato, Y. Kondo, U. Akiba, Y. Ishigaki, R. Katoono, T. Suzuki

Tetrahedron Letters   59 ( 14 ) 1372 - 1376   2018.03  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Double bond formation based on nitroaldol reaction and radical elimination: a prototype segment connection method for the total synthesis of nigricanoside A dimethyl ester.

T. Tsunoda, K. Fujiwara, S. Okamoto, Y. Kondo, U. Akiba, Y. Ishigaki, R. Katoono, T. Suzuki

Tetrahedron Letters   59 ( 19 ) 1846 - 1850   2018.03  [Refereed]

Research paper (journal)   Domestic Co-author

DOI

Oxidative desulfurization of electron-donating 5,5,7,7-tetraaryl-5,7-dihydrodibenzo[c,e] thiepins and the related heterocycles: Generation of dicationic dyes upon two-electron oxidation.

T. Suzuki, T. Kuroda, H. Tamaoki, S, Higasa, T. Nehira, R. Katoono, Y. Ishigaki, K. Fujiwara, T. Fukushima, H. Yamada

Heterocycles   95 ( 2 ) 816 - 829   2017.11  [Refereed]

Research paper (journal)   Domestic Co-author

High selectivity and extractability of palladium from chloride leach liquors of an automotive catalyst residue by azothiacalix(4)arene derivative.

K. Senthil, U. Akiba, K. Fujiwara, F. Hamada, Y. Kondo

Hydrometallurgy   169   478 - 487   2017.10  [Refereed]

Research paper (journal)   Domestic Co-author

Highly Selective Separation and Recovery of Pd(II) from the Automotive Catalyst Residue with the Thiocarbamoyl substituted Azothiacalix[4]arene Derivative

K. Senthil, U. Akiba, K. Fujiwara, Y. Kondo

Separation Science and Technology (Philadelphia)   52 ( 8 ) 1365 - 1376   2017.02  [Refereed]

Research paper (journal)   Domestic Co-author

Synthesis of the ABCDEF-ring of ciguatoxin 3C

T. Sato, K. Fujiwara, K. Nogoshi, A. Goto, D. Domon, N. Kawamura, Y. Nomura, D. Sato, H. Tanaka, A. Murai, Y. Kondo, U. Akiba, R. Katoono, H. Kawai, T. Suzuki

Tetrahedron   73 ( 6 ) 703 - 726   2017.02  [Refereed]

Research paper (journal)   Domestic Co-author

Bis(diarylethenyl)-thiophenes, -bithiophenes, and -terthiophenes: a new series of electrochromic systems that exhibit a fluorescence response

Y. Ishigaki, H. Kawai, R. Katoono, K. Fujiwara, H. Higuchi, H. Kikuchi, T. Suzuki

Canadian Journal of Chemistry   95 ( 3 ) 243 - 252   2017.01  [Refereed]

Research paper (journal)   Domestic Co-author

New Heterocyclic Dithioether Ligands for Highly Selective Separation and Recovery of Pd(II) from Acidic Leach Liquors of Spent Automobile Catalyst

K. Senthil, U. Akiba, K. Fujiwara, F. Hamada, Y. Kondo

Industrial and Engineering Chemistry Research   56 ( 4 ) 1036 - 1047   2017.01  [Refereed]

Research paper (journal)   Domestic Co-author

Biological Activities of p-Terphenyl Compounds Isolated from Edible Mushrooms

T. Norikura, K. Fujiwara, H. Matsue, K. Iwai

FFI Journal   221 ( 3 ) 232 - 238   2016.08  [Refereed]

Research paper (journal)   Domestic Co-author

Redox-induced Conformational Changes in 1,3-Propylene- and m-Xylylenebis[5-(10-butyl-5,10-dihydrobenzo[a]indolo[2,3-c]carbazole)]: Twin-BIC Donors that Form Sandwich-like Dimeric Cations Exhibiting NIR Absorption

T. Suzuki, W. Nojo, Y. Sakano, R. Katoono, Y. Ishigaki, H. Ohno, K. Fujiwara

Chem. Lett.   45 ( 7 ) 720 - 722   2016.07  [Refereed]

Research paper (journal)   Domestic Co-author