論文 - 末永　聖武

Biselides A-E: novel polyketides from the Okinawan ascidian Didemnidae sp.

Teruya Toshiaki, Suenaga Kiyotake, Maruyama Sakiko, Kurotaki Mineko, Kigoshi Hideo

Tetrahedron 61 （ 27 ） 6561 - 6567 2005年07月

査読有り,  ISSN  0040-4020

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<p>Five new polyketides, biselides A (1), B (2), C (3), D (4), and E (5), were isolated from the Okinawan ascidian Didemnidae sp. Their structures were determined by spectroscopic analysis. Biselides A (1), B (2), and C (3) showed cytotoxicity against human cancer cells NCI-H460 and MDA-MB-231.</p>

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Phormidinines A and B, novel 2-alkylpyridine alkaloids from the cyanobacterium Phormidium sp.

Teruya Toshiaki, Kobayashi Keiko, Suenaga Kiyotake, Kigoshi Hideo

Tetrahedron Letters 46 （ 23 ） 4001 - 4003 2005年06月

査読有り,  ISSN  0040-4039

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<p>Novel 2-alkylpyridine alkaloids, phormidinines A (1) and B (2), were isolated from cyanobacterium Phormidium sp. Their structures were determined by spectroscopic analysis. The absolute stereochemistry of 1 was established by the modified Mosher's method.</p>

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Formal synthesis of optically active ingenol via ring-closing olefin metathesis

Watanabe Kazushi, Suzuki Yuto, Aoki Kenta, Sakakura Akira, Suenaga Kiyotake, Kigoshi Hideo

Journal of Organic Chemistry 69 （ 23 ） 7802 - 7808 2004年11月

査読有り,  ISSN  0022-3263

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<p>The construction of strained carbon skeletons by ring-closing olefin metathesis (RCM) was investigated. With well-designed diene 4, RCM was found to be applicable to the formation of a highly strained inside-outside bicyclo[4.4.1]undecane skeleton of ingenol, a bioactive diterpenoid, and formal total synthesis of optically active ingenol (1) was achieved. The key features of this synthesis are construction of an A-ring by spirocyclization of the ketone with an allylic chloride unit, 26, and ring closure of a B-ring by olefin metathesis. Starting from Funk's keto ester 6, the key intermediate aldehyde 9 in Winkler's total synthesis was synthesized in eight steps in 12.5% overall yield. This strategy of direct cyclization of a strained inside-outside skeleton provided the first easy access to optically active ingenol.</p>

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Spongiacysteine, a novel cysteine derivative from marine sponge Spongia sp.

Kobayashi Keiko, Shimogawa Hiroki, Sakakura Akira, Teruya Toshiaki, Suenaga Kiyotake, Kigoshi Hideo

Chemistry Letters 33 （ 10 ） 1262 - 1263 2004年10月

査読有り,  ISSN  0366-7022

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<p>A novel cysteine derivative, spongiacysteine (1), was isolated from marine sponge Spongia sp. The gross structure was elucidated by detailed spectroscopic analysis, and the absolute stereostructure was established by its total synthesis. This compound showed moderate antimicrobial activity against rice blast fungus Pyricularia oryzae.</p>

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Aurilide, a cytotoxic depsipeptide from the sea hare Dolabella auricularia: isolation, structure determination, synthesis, and biological activity

Suenaga Kiyotake, Mutou Tsuyoshi, Shibata Takunobu, Itoh Takashi, Fujita Tatsuya, Takada Noboru, Hayamizu Kozue, Takagi Masaki, Irifune Taiji, Kigoshi Hideo, Yamada Kiyoyuki

Tetrahedron 60 （ 38 ） 8509 - 8527 2004年09月

査読有り,  ISSN  0040-4020

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<p>The bioassay-guided fractionation of the cytotoxic constituents of the Japanese sea hare Dollabella auricularia led to the isolation of aurilide (1), a 26-membered cyclodepsipeptide. The gross structure of 1 was established by spectroscopic analysis including 2D NMR techniques. The absolute stereostructure was determined by chiral HPLC analysis of acid hydrolysates of 1 and by the enantioselective synthesis of a degradation product arising from a dihydroxylated fatty acid portion. The enantioselective synthesis of 1 was achieved in 12% overall yield (16 steps) and confirmed the absolute stereostructure of 1. The cytotoxicity of 1 was evaluated using a synthetic sample, which was found to exhibit potent cytotoxicity against HeLa S ₃ cells with an IC₅₀ of 0.011 μg/mL. Further biological and pharmacological studies of 1 have been carried out by using synthetic 1. Graphical abstract.</p>

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Biselides A and B, novel macrolides from the okinawan ascidian didemnidae sp.

Teruya Toshiaki, Shimogawa Hiroki, Suenaga Kiyotake, Kigoshi Hideo

Chemistry Letters 33 （ 9 ） 1184 - 1185 2004年09月

査読有り,  ISSN  0366-7022

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<p>Two new macrolides, biselides A (1) and B (2), were isolated from the Okinawan ascidian Didemnidae sp. Their structures were determined by spectroscopic analysis.</p>

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Total synthesis of (-)-ent-jolkinolide D

Suenaga Kiyotake, Takayanagi Yui, Yamaura Masashi, Kigoshi Hideo

Chemistry Letters 33 （ 7 ） 918 - 919 2004年07月

査読有り,  ISSN  0366-7022

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<p>The first total synthesis of the enantiomer of jolkinolide D, a bioactive diterpene from Euphorbia jolkini Boiss, was achieved from abietic acid. The enantiomer did not exhibit the biological activities that the natural jolkinolide D possesses.</p>

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Synthesis and actin-depolymerizing activity of mycalolide analogs

Suenaga Kiyotake, Miya Saori, Kuroda Takeshi, Handa Tomohisa, Kanematsu Kengo, Sakakura Akira, Kigoshi Hideo

Tetrahedron Letters 45 （ 28 ） 5383 - 5386 2004年07月

査読有り,  ISSN  0040-4039

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<p>Mycalolide analog 4, consisting only of the side chain of mycalolide B (2), was stereoselectively synthesized and was found to have strong actin-depolymerizing activity.</p>

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Inducing substance for abalone larval metamorphosis from the crustose coralline alga Hydrolithon samoense

Suenaga Kiyotake, Hori Hidenari, Ishida Hitoshi, Nukaya Haruo, Roberts Rodney D., Tsuji Kuniro

Fisheries Science 70 （ 2 ） 342 - 344 2004年04月

査読有り,  ISSN  0919-9268

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Bioorganic Studies on Marine Natural Products with Bioactivity, Such as Antitumor Activity and Feeding Attractance

Suenaga Kiyotake

Bulletin of the Chemical Society of Japan 77 （ 3 ） 443 - 451 2004年03月

査読有り,  ISSN  0009-2673

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<p>This account describes bioorganic studies on marine natural products with bioactivity, such as antitumor activity and feeding attractance. Chemical studies on the following bioactive compounds of marine origin have been carried out: 1) feeding attractants for the starfish Acanthaster planci, 2) potent toxins from shellfish of the genus Pinna that cause food poisoning, and 3) a variety of cytotoxic and antitumor compounds from marine invertebrates including sea hares, Dolabella auricularia and Aplysia kurodai. Their isolation, structure elucidation, synthesis, and some aspects of their biological activities are summarized.</p>

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Isolation of tribromoacetamide from an okinawan alga and biological activities of its analogs

Kigoshi Hideo, Ichino Takao, Takada Noboru, Suenaga Kiyotake, Yamada Akihiro, Yamada Kaoru, Uemura Daisuke

Chemistry Letters 33 （ 2 ） 98 - 99 2004年02月

査読有り,  ISSN  0366-7022

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<p>Tribromoacetamide was isolated from the Okinawan alga Wrangelia species, and the biological activities of this compound and its analogs were investigated.</p>

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Nakiterpiosin, a novel cytotoxic C-nor-D-homosteroid from the Okinawan sponge Terpios hoshinota

Teruya Toshiaki, Nakagawa Satoru, Koyama Tomoyuki, Suenaga Kiyotake, Kita Masaki, Uemura Daisuke

Tetrahedron Letters 44 （ 28 ） 5171 - 5173 2003年07月

査読有り,  ISSN  0040-4039

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<p>A novel cytotoxic compound, nakiterpiosin (1), was isolated from the Okinawan sponge Terpios hoshinota. Its structure was determined by spectroscopic analysis. The absolute stereostructure of 1 was also determined by a modified Mosher's method. Nakiterpiosin showed potent cytotoxicity against P388 cells.</p>

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Haterumaimides J and K, potent cytotoxic diterpene alkaloids from the ascidian Lissoclinum species

Uddin M. Jasim, Kokubo Susumu, Ueda Katsuhiro, Suenaga Kiyotake, Uemura Daisuke

Chemistry Letters  （ 10 ） 1028 - 1029 2002年10月

査読有り,  ISSN  0366-7022

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<p>Two unique cytotoxic diterpene alkaloids, haterumaimides J and K, were isolated from the ascidian Lissoclinum sp. Their structures were elucidated by an extensive analysis of spectral data. Haterumaimides J and K showed potent cytotoxicity against P388 cells, with IC₅₀ values of 0.23 ng/mL and 0.45 ng/mL, respectively.</p>

Hedathiosulfonic acids A and B, novel thiosulfonic acids from the deep-sea urchin Echinocardium cordatum

Kita Masaki, Watanabe Masami, Takada Noboru, Suenaga Kiyotake, Yamada Kaoru, Uemura Daisuke

Tetrahedron 58 （ 32 ） 6405 - 6412 2002年08月

査読有り,  ISSN  0040-4020

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<p>Hedathiosulfonic acids A and B were isolated from the deep-sea urchin Echinocardium cordatum and were determined to be novel 6-undecanethiosulfonic acids by 2D NMR, HRMS, and methylation reaction. The stereostructure of hedathiosulfonic acid A was determined by the analysis of its degradation product, a cyclic β-hydroxysulfone. Hedathiosulfonic acids exhibited acute toxicity. We carried out various model reactions of the olefinic compounds with thiosulfonic acids and proved that, as is the case with natural products, synthesized thiosulfonic acid possessing a carbon-carbon double bond was converted into β-hydroxysulfone in the presence of oxygen.</p>

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Total synthesis of attenols A and B

Araki Keisuke, Suenaga Kiyotake, Sengoku Tetsuya, Uemura Daisuke

Tetrahedron 58 （ 10 ） 1983 - 1995 2002年03月

査読有り,  ISSN  0040-4020

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<p>The enantioselective synthesis of attenols A and B, cyclic polyethers of marine origin, was accomplished on a semigram scale by using diastereoselective hydroboration, coupling with lithium acetylide, Lindlar reduction and acid-catalyzed acetal formation. The configuration of the remaining undetermined spiro acetal carbon was unambiguously determined to be 11S using this ample supply of attenol A. The antitumor activities of synthetic attenol A were also examined.</p>

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Cytotoxicity and actin-depolymerizing activity of aplyronine A, a potent antitumor macrolide of marine origin, and its analogs

Kigoshi Hideo, Suenaga Kiyotake, Takagi Masaki, Akao Atsushi, Kanematsu Kengo, Kamei Noriyuki, Okugawa Youko, Yamada Kiyoyuki

Tetrahedron 58 （ 6 ） 1075 - 1102 2002年02月

査読有り,  ISSN  0040-4020

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<p>Artificial analogs of aplyronine A (1), a potent antitumor macrolide, were synthesized and structure-activity (cytotoxicity and actin-depolymerizing activity) relationships were investigated; the side-chain in 1 was found to play a key role in both biological activities.</p>

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Terpiodiene, a Novel Tricyclic Alcohol from the Okinawan Sponge Terpios hoshinota.

Teruya Toshiaki, Nakagawa Satoru, Koyama Tomoyuki, Suenaga Kiyotake, Uemura Daisuke

Chemistry Letters  （ 1 ） 38 - 39 2002年01月

査読有り,  ISSN  0366-7022

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<p>Terpiodiene (1), a novel tricyclic alcohol, was isolated from the Okinawan sponge Terpios hoshinota, which overgrows and kills corals. Its structure was determined by spectroscopic analysis and the modified Mosher's method. This compound exhibited moderate cytotoxicity against P388 cells.</p>

Arachidonic acid and α-linolenic acid, feeding attractants for the crown-of-thorns sea star Acanthaster planci, from the sea urchin Toxopneustes pileolus

Teruya Toshiaki, Suenaga Kiyotake, Koyama Tomoyuki, Nakano Yoshikatsu, Uemura Daisuke

Journal of Experimental Marine Biology and Ecology 266 （ 2 ） 123 - 134 2001年12月

査読有り,  ISSN  0022-0981

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<p>In the tropical zones of the Indo-Pacific Oceans, the crown-of-thorns sea star Acanthaster planci, as the predator of corals, destroys coral reefs. We recently found that viscera of the sea urchin Toxopneustes pileolus produced a feeding attractant for this sea star. Using our simple bioassay system, we isolated arachidonic acid and α-linolenic acid as feeding attractants from T. pileolus. This is the first report about the sea star A. planci being attracted to unsaturated fatty acids. Interestingly, other unsaturated fatty acids such as eicosapentaenoic acid, docosahexaenoic acid and linoleic acid showed no activity. Our preliminary experiments indicated that these attractants have an attractive effect for the sea star both in the aquarium and in the sea. We anticipated that these attractants could be used to control A. planci. In addition, we verified the existence of arachidonic acid in the coral as one of the feeding attractants.</p>

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Auriculol, a cytotoxic oxygenated squalene from the Japanese sea hare Dolabella auricularia

Kigoshi Hideo, Itoh Takashi, Ogawa Takafumi, Ochi Kenya, Okada Mayuko, Suenaga Kiyotake, Yamada Kiyoyuki

Tetrahedron Letters 42 （ 42 ） 7461 - 7464 2001年10月

査読有り,  ISSN  0040-4039

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<p>Auriculol, a cytotoxic oxygenated squalene, was isolated from the Japanese sea hare Dolabella auricularia, and its stereostructure was elucidated by spectral analysis and organic synthesis.</p>

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Catharsitoxins from the Chinese remedy qiung laug

Suenaga Kiyotake, Shimogawa Hiroki, Nakagawa Satoru, Uemura Daisuke

Tetrahedron Letters 42 （ 40 ） 7079 - 7081 2001年10月

査読有り,  ISSN  0040-4039

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<p>Novel imidazole compounds, catharsitoxins A, B, C, D, E and F, were isolated from the Chinese remedy qiung laug. Their structures were determined by 2D NMR. To confirm their structures and to ensure an adequate supply for further biological studies, catharsitoxins A and D were synthesized.</p>

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