Toyonobu Usuki

Prof. Dr. Toyonobu Usuki

Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University,Tokyo, Japan
orcid

Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 August 2011 in Chemical Communications
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Journal Article
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Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki
NYNanae Yasuda
Nanae Yasuda
Masahiro Yoshizawa-FujitaMasahiro Yoshizawa-Fujita
Masahiro Yoshizawa-Fujita
MRMasahiro Rikukawa
Masahiro Rikukawa
Shikimic acid, the starting material in the commercial synthesis of oseltamivir phosphate (Tamiflu®), was efficiently extracted and isolated from Ginkgo biloba leaves utilizing the ionic liquid 1-butyl-3-methylimidazolium chloride ([bmim]Cl), which dissolves cellulose.

1 September 2021 in Bioorganic & Medicinal Chemistry Letters
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Journal Article
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LLLokadi Pierre Luhata
Lokadi Pierre Luhata
Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki

5 March 2014 in Organic Letters
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Journal Article
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Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki
TSTakanori Sugimura
Takanori Sugimura
AKAkira Komatsu
Akira Komatsu
YKYohei Koseki
Yohei Koseki

18 June 2020 in European Journal of Organic Chemistry
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Journal Article
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NTNao Tanaka
Nao Tanaka
Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki
Hydrogenation of over a dozen aromatic compounds, including both heteroarenes and arenes, over palladium on carbon (Pd/C, 1–100 mol%) with H2‐balloon pressure at room temperature is reported. Analyses using pyridine as a model substrate revealed that acetic acid was the best solvent, as using only 1 mol% Pd/C provided piperidine quantitatively. Substrate scope analysis and density functional theory calculations indicated that reaction rates are highly dependent on frontier molecular orbital characteristics and the steric bulkiness of substituents. Moreover, the established method was used for the concise synthesis of the anti‐Alzheimer drug donepezil (Aricept®).

30 January 2012 in Chemical Communications
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Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki
HYHaruka Yamada
Haruka Yamada
THTakahiro Hayashi
Takahiro Hayashi
HYHiroto Yanuma
Hiroto Yanuma
YKYohei Koseki
Yohei Koseki
YLYong Y. Lin
Yong Y. Lin
Desmosine, a crosslinking amino acid of elastin, is an attractive biomarker for diagnosis of chronic obstructive pulmonary disease (COPD). In this study, the first total synthesis of (+)-desmosine was achieved in 11% overall yield in 13 steps utilizing stepwise and regioselective Sonogashira cross-coupling reactions.

21 March 2014 in Molecules
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SZStefanie Zimmermann
Stefanie Zimmermann
GFGerda Fouché
Gerda Fouché
MMMaria De Mieri
Maria De Mieri
YYYukiko Yoshimoto
Yukiko Yoshimoto
Toyonobu UsukiToyonobu Usuki
Toyonobu Usuki
MAMichael Adams
Michael Adams
Sesquiterpene lactones (STLs) are natural products that have potent antitrypanosomal activity in vitro and, in the case of cynaropicrin, also reduce parasitemia in the murine model of trypanosomiasis. To explore their structure-antitrypanosomal activity relationships, a set of 34 natural and semi-synthetic STLs and amino-STLs was tested in vitro against T. b. rhodesiense (which causes East African sleeping sickness) and mammalian cancer cells (rat bone myoblast L6 cells). It was found that the α-methylene-γ-lactone moiety is necessary for both antitrypanosomal effects and cytotoxicity. Antitrypanosomal selectivity is facilitated by 2-(hydroxymethyl)acrylate or 3,4-dihydroxy-2-methylenebutylate side chains, and by the presence of cyclopentenone rings. Semi-synthetic STL amines with morpholino and dimethylamino groups showed improved in vitro activity over the native STLs. The dimethylamino derivative of cynaropicrin was prepared and tested orally in the T. b. rhodesiense acute mouse model, where it showed reduced toxicity over cynaropicrin, but also lost antitrypanosomal activity.