M
Masashi Yokoya
Researcher at Meiji Pharmaceutical University
Publications - 23
Citations - 138
Masashi Yokoya is an academic researcher from Meiji Pharmaceutical University. The author has contributed to research in topics: Uncaria tomentosa & Tetrahydroisoquinoline. The author has an hindex of 7, co-authored 23 publications receiving 122 citations. Previous affiliations of Masashi Yokoya include Chiba University.
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A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, from Peruvian Uña de Gato (Uncaria tomentosa).
Mariko Kitajima,Ken-ichiro Hashimoto,Masashi Yokoya,Hiromitsu Takayama,Norio Aimi,Shin-ichiro Sakai +5 more
TL;DR: A new gluco indole alkaloid was obtained from Peruvian Uña de Gato and a characteristic feature of the compound was the quick replacement of the methylene hydrogens on C-14 with deuterium that was observed when it was dissolved in CD3OD.
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Synthesis and absolute configuration of a new 3,4-dihydro-β-carboline-type alkaloid, 3,4-dehydro-5(S)-5-carboxystrictosidine, isolated from Peruvian Uña de Gato (Uncaria tomentosa)
TL;DR: The structure including the absolute configuration of a new glucoalkaloid, 3,4-dehydro-5(S)-5-carboxystrictosidine, isolated from Peruvian Uña de Gato (Cat's Claw), was confirmed by synthesis starting from secologanin and L-tryptophan.
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Two New 19-Hydroxyursolic Acid-type Triterpenes from Peruvian ‘Uña de Gato’ (Uncaria tomentosa)
TL;DR: In this paper, two triterpenes having a 19-hydroxyursolic acid skeleton were isolated from Uncaria tomentosa, a traditional herbal medicine in Peru, by spectroscopic analyses and chemical conversion.
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Enantioselective Synthesis of ent-Sedridine and (+)-Coniine via Proline-Catalyzed Mannich Reaction
TL;DR: Proline-catalyzed three component Mannich reaction using 5-hydroxypentanal as a substrate was achieved in high enantioselectivity to construct a chiral center at C-2 position of 2-substituted piperidine alkaloids as mentioned in this paper.
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Synthesis of tetrahydroisoquinoline antitumor natural products: construction of tricyclic lactams through Pictet-Spengler-type cyclization of N-methyl-3-arylmethylpiperazine-2,5-dione with ethyl diethoxyacetate
TL;DR: The Pictet-Spengler-type cyclization of the O,N-acetal of 3-arylmethylpiperazine-2,5-dione (8) in high yield was used for the total synthesis of renieramycin G and cribrostatin 4.