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Biomedical subjects

Naonobu Tanaka

Publications and source records attributed to Naonobu Tanaka.

7 recordsLinked to original sources

Xanthones from stems of Hypericum chinense.

Six new xanthones, 4,6-dihydroxy-2,3-dimethoxyxanthone (1), 2,6-dihydroxy-3,4-dimethoxyxanthone (2), 6-hydroxy-2,3,4-trimethoxyxanthone (3), 3,6-dihydroxy-1,2-dimethoxyxanthone (4), 4,7-dihydroxy-2,3-dimethoxyxanthone (5), and 3,7-dihydroxy-2,4-dimethoxyxanthone (6) were isolated from the stems of Hypericum chinense, together with four known xanthones. Their structures were established based on spectroscopic studies.

Chromatography, High Pressure Liquid↗

Xanthones from Hypericum chinense.

Six xanthones, 1,3,7-trihydroxy-2-(2-hydroxy-3-methyl-3-butenyl)-xanthone (1), 1,7-dihydroxy-2,3-[2''-(1-hydroxy-1-methylethyl)-dihydrofurano]-xanthone (2), 1,3,7-trihydroxy-5-methoxyxanthone (3), 1,7-dihydroxy-5,6-dimethoxyxanthone (4), 4,5-dihydroxy-2,3-dimethoxyxanthone (5), 1,3-dihydroxy-2,4-dimethoxyxanthone (6) and 21 known xanthones were isolated from the leaves and stems of Hypericum chinense. Their structures were established based on spectroscopic studies.

Hypericum↗

Chemical constituents from the peels of Citrus sudachi.

A methanol extract of the peels of Citrus sudachi gave five new compounds (1-5) and 27 known compounds. The structures were elucidated on the basis of spectroscopic evidence. Several of these compounds were assayed for antimicrobial activity against methicillin-resistant Staphylococcus aureus and Helicobacter pylori, and sudachitin (6) and 3'-demethoxysudachitin (7) were the most active.

Anti-Bacterial Agents↗

Biyouyanagin A, an anti-HIV agent from Hypericum chinense L. var. salicifolium.

[structure: see text] A structurally unique hydrophobic compound, biyouyanagin A, was isolated from the MeOH extract of the leaves of Hypericum chinense L. var. salicifolium. The structure of biyouyanagin A was elucidated on the basis of spectroscopic evidence. Biyouyanagin A showed a significant activity against HIV and inhibited cytokine production.

Anti-HIV Agents↗

Kaurane and abietane diterpenoids from Tripterygium doianum (Celastraceae).

Extraction of Tripterygium doianum (Celastraceae) afforded five new diterpenoids and 11 known diterpenoids belonging to the ent-kaurane and abietane families. Their structures were established based on spectroscopic studies. The isolated compounds showed moderate cytotoxicity against human tumor cell assays.

Abietanes↗

Prenylated benzophenones and xanthones from Hypericum scabrum.

Two new polyprenylated benzophenones, a new polyprenylated phloroglucinol, and six new xanthone derivatives were isolated from the aerial parts of the Uzbekistan medicinal plant Hypericum scabrum. Their structures were elucidated on the basis of spectroscopic evidence. The isolated compounds showed moderate cytotoxicity for human tumor cells.

Antineoplastic Agents, Phytogenic↗

Terpenoids from Tripterygium doianum (Celastraceae).

The extract of Tripterygium doianum (Celastraceae) afforded three triterpenoids [3beta-acetoxy-11-ursen-13alpha,30-olide, 25-chloro-24-hydroxytirucall-7-en-3-one and tirucall-7-en-3,24-dione], two sesquiterpenoids [5alpha-acetoxy-1beta,8alpha-bis-cinnamoyl-4alpha-hydroxydihydroagarofuran and 5alpha-acetoxy-1beta-benzoyl-8alpha-cinnamoyl-4alpha-hydroxydihydroagarofuran] and nine known triterpenoids. Their structures were established based on spectroscopic studies.

Magnetic Resonance Spectroscopy↗