論文 - 末永　聖武

Dolabelides C and D, cytotoxic macrolides isolated from the sea hare Dolabella auricularia

Suenaga Kiyotake, Nagoya Tomohiro, Shibata Takunobu, Kigoshi Hideo, Yamada Kiyoyuki

Journal of Natural Products 60 （ 2 ） 155 - 157 1997年02月

査読有り,  ISSN  0163-3864

　概要を見る

<p>Two new cytotoxic 24-membered macrolides, dolabelides C and D, were isolated from the Japanese sea hare Dolabella auricularia. Their gross structures were deduced by spectroscopic analysis including the 2D NMR technique, and their absolute stereochemistry was determined by means of chemical correlation with the known dolabelide A. Dolabelides C and D exhibited cytotoxicities against HeLa S₃ cells with IC₅₀ values of 1.9 and 1.5 μg/mL, respectively.</p>

• Access to Document (DOI)

Isolation and stereostructure of aurilide, a novel cyclodepsipeptide from the Japanese sea hare Dolabella auricularia

Suenaga Kiyotake, Mutou Tsuyoshi, Shibata Takunobu, Itoh Takashi, Kigoshi Hideo, Yamada Kiyoyuki

Tetrahedron Letters 37 （ 37 ） 6771 - 6774 1996年09月

査読有り,  ISSN  0040-4039

　概要を見る

<p>Aurilide (1), a new 26-membered cyclodepsipeptide, has been isolated from the Japanese sea hare Dolabella auricularia. The gross structure of 1 was established by spectroscopic analysis. The absolute stereostructure of 1 was determined by HPLC analysis of amino acid components and isoleucic acid obtained from acidic hydrolysis of 1 and by the enantioselective synthesis of the tris(p-bromobenzoate) 3 derived from the dihydroxy acid moiety.</p>

• Access to Document (DOI)

Aplyronine A, a potent antitumor substance of marine origin, aplyronines B and C, and artificial analogues

Kigoshi Hideo, Suenaga Kiyotake, Mutou Tsuyoshi, Ishigaki Takeshi, Atsumi Toshiyuki, Ishiwata Hiroyuki, Sakakura Akira, Ogawa Takeshi, Ojika Makoto, Yamada Kiyoyuki

Journal of Organic Chemistry 61 （ 16 ） 5326 - 5351 1996年08月

査読有り,  ISSN  0022-3263

　概要を見る

<p>The enantioselective total synthesis of aplyronine A (1), a potent antitumor substance of marine origin, was achieved by a convergent approach. Three segments 4, 5, and 6, corresponding to the C5-C11, C21-C27, and C28-C34 portions of aplyronine A (1), were prepared using the Evans aldol reaction and the Sharpless epoxidation as key steps. The coupling reaction of 4 with iodide 7 followed by Julia olefination with sulfone 8 gave the C5-C20 segment 9, while the Julia coupling reaction between segments 5 and 6 provided the C21-C34 segment 10. Julia olefination between segments 9 and 10 and the subsequent four-carbon homologation reaction led to seco acid 83, which was converted into aplyronine A (1) by Yamaguchi lactonization followed by the introduction of two amino acids. The use of the [(3,4-dimethoxybenzyl)oxy]methyl group as a protecting group for the hydroxyl at C29 was crucial for this synthesis. The enantioselective synthesis of two natural congeners, aplyronines B (2) and C (3), was also carried out using the intermediates for the synthesis of 1, which determined the absolute stereostructures of 2 and 3 unambiguously. To study the structure-cytotoxicity relationships of aplyronines, artificial analogues of 1 were synthesized and their cytotoxicities were evaluated: the trimethylserine moiety, two hydroxyl groups, and the side chain portion in 1 turned out to be important in the potent cytotoxicity shown by 1. Biological studies with aplyronine A (1) showed that 1 inhibited polymerization of G-actin to F-actin and depolymerized F-actin to G-actin.</p>

• Access to Document (DOI)

Auripyrones A and B, cytotoxic polypropionates from the sea hare Dolabella auricularia

Suenaga Kiyotake, Kigoshi Hideo, Yamada Kiyoyuki

Tetrahedron Letters 37 （ 29 ） 5151 - 5154 1996年07月

査読有り,  ISSN  0040-4039

　概要を見る

<p>Two new polypropionates, auripyrones A (1) and B (2), have been isolated as cytotoxins from the sea hare Dolabella auricularia. The gross structures of 1 and 2 were determined by spectroscopic analysis, and their relative stereochemistry except for the ester moiety of 2 was established on the basis of the NOESY data.</p>

• Access to Document (DOI)

Absolute stereochemistry and synthesis of aplyronines B and C, the congeners of aplyronine A, a potent antitumor substance of marine origin

Suenaga Kiyotake, Ishigaki Takeshi, Sakakura Akira, Kigoshi Hideo, Yamada Kiyoyuki

Tetrahedron Letters 36 （ 28 ） 5053 - 5056 1995年07月

査読有り,  ISSN  0040-4039

　概要を見る

<p>Synthesis of aplyronines B and C, the congeners of aplyronine A, was achieved enantioselectively, which established their stereostructures.</p>

• Access to Document (DOI)

Total synthesis of aplyronine A, a potent antitumor substance of marine origin

Kigoshi Hideo, Ojika Makoto, Ishigaki Takeshi, Suenaga Kiyotake, Mutou Tsuyoshi, Sakakura Akira, Ogawa Takeshi, Yamada Kiyoyuki

Journal of the American Chemical Society 116 （ 16 ） 7443 - 7444 1994年08月

査読有り,  ISSN  0002-7863

Synthetic Studies on Aplyronine A, a Potent Antitumor Substance of Marine Origin

Kigoshi Hideo, Ojika Makoto, Suenaga Kiyotake, Mutou Tsuyoshi, Hirano Junko, Sakakura Akira, Ogawa Takeshi, Nisiwaki Masanori, Yamada Kiyoyuki

Tetrahedron Letters 35 （ 8 ） 1247 - 1250 1994年02月

査読有り,  ISSN  0040-4039

　概要を見る

<p>The C21-C34 segment 2 of aplyronine A (1), a potent antitumor substance of marine origin, was synthesized enantioselectively in 25 steps (17% overall yield) from imide 11.</p>

• Access to Document (DOI)