Faculty Profiles - KUBOTA Takaaki

P-33 Nagelamides K, M, and N, Novel Bromopyrrole Alkaloids from Okinawan Marine Sponge Agelas sp(Poster Presentation)

Araki Atsushi, Yasuda Tetsuro, Kubota Takaaki, Mikami Yuzuru, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 0 ( 50 ) 361 - 366 2008.9

Language：Japanese Publisher：Symposium on the chemistry of natural products

DOI： 10.24496/tennenyuki.50.0_361

ナガサキオトギリ由来の新規フロログルシノール誘導体petiolin Dの構造

田中直伸, 久保田高明, 石山玄明, 小林淳一, 柏田良樹, 高石喜久, 伊藤淳二, 三上襄, 城始勇

日本生薬学会年会講演要旨集 55th 188 2008.9

沖縄産海綿由来の新規ブロモピロールアルカロイドの構造

荒木敦, 安田鉄郎, 久保田高明, 三上襄, 小林淳一

天然有機化合物討論会講演要旨集 50th ( 50 ) 361-366 - 366 2008.9

Language：Japanese Publisher：Symposium on the chemistry of natural products

Bromopyrrole alkaloids are known to be one of the most common metabolites contained in marine sponges. During our search for bioactive substances from marine organisms, we have isolated bromopyrrole alkaloids with unique cyclic skeletons from sponges of the genus Agelas or Hymeniacidon. Recently, three new bromopyrrole alkaloids, nagelamides K, M, and N (1-3), have been isolated from an Okinawan marine sponge Agelas sp. (SS-1134). The structures and relative stereochemistry of 1〜3 were elucidated on the basis of spectroscopic data. Nagelamide K (1) is a new dimeric bromopyrrole alkaloid possessing a rare piperidinoiminoimidazolone ring with an aminoimidazole ring and a taurine unit. Nagelamide M (2) is a novel bromopyrrole alkaloid possessing an 2-amino-octahydropyrrolo[2,3-d]imidazol ring with a taurine unit, while nagelamide N (3) is a new bromopyrrole alkaloid consisting of an 2-amino-tetrahydroimidazol-4-one ring with a taurine unit and 3-(dibromopyrrole-2-carboxamido)propanoic acid moiety. Nagelamides K, M, and N (1-3) showed modest antimicrobial activity.

DOI： 10.24496/tennenyuki.50.0_361

シマサルスベリより単離した新規Lythraceaeアルカロイドの構造

久保田高明, 渡辺梢, 小林淳一, 新里孝和, 伊藤淳二, 三上襄

日本生薬学会年会講演要旨集 55th 219 2008.9

ナガサキオトギリより単離した新規フロログルシノール誘導体petiolin A‐Cの構造

田中直伸, 久保田高明, 荒木敦, 柏田良樹, 高石喜久, 三上襄, 小林淳一

日本薬学会年会要旨集 128th ( 2 ) 11 2008.3

沖縄産海綿Spongia sp.由来の新規テルペノイドMetachromin R〜Tの構造

山田美香, 高橋洋平, 久保田高明, 小林淳一

日本薬学会年会要旨集 128th ( 2 ) 11 2008.3

ユズリハ科植物由来の新規アルカロイドCalyciphylline H〜Mの構造

八幡弘子, 齊藤静夏, 久保田高明, 小原祐太郎, 中畑則道, 小林淳一

日本薬学会年会要旨集 128th ( 2 ) 12 2008.3

沖縄産海綿Amphimedon sp.由来の新規アルカロイドNakinadine Aの構造

久保田高明, 西貴美, 佐々木琢磨, 小林淳一

日本薬学会年会要旨集 128th ( 2 ) 12 2008.3

Multi Phenotypic Screeningによる生理活性物質の作用解析

風見紗弥香, 風見紗弥香, 臼井健郎, 臼井健郎, 久保田高明, 小林淳一, 長田裕之, 長田裕之

日本農芸化学会大会講演要旨集 2008 9 2008.3

アスヒカズラより単離した新規アルカロイドの構造

久保田高明, 八幡弘子, 石内勘一郎, 小林淳一

日本生薬学会年会講演要旨集 54th 226 2007.9

P-11 Calyciphyllines C〜G, Novel Daphniphyllum Alkaloids from Daphniphyllum calycinum

Saito Shizuka, Kubota Takaaki, Fukushi Eri, Kawabata Jun, Zhang Huiping, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 0 ( 49 ) 271 - 276 2007.8

Language：Japanese Publisher：Symposium on the chemistry of natural products

DOI： 10.24496/tennenyuki.49.0_271

ユズリハ科植物由来の新規アルカロイドcalyciphylline C〜Gの構造と生物活性

齊藤静夏, 久保田高明, 福士江里, 川端潤, ZHANG Huiping, 小林淳一

天然有機化合物討論会講演要旨集 49th ( 49 ) 271-276 - 276 2007.8

Language：Japanese Publisher：Symposium on the chemistry of natural products

Daphniphyllum alkaloids are a structually diverse group of natural products with unique fused-heterocyclic skeletons, which are elaborated by trees of the genus Daphniphyllum (Daphniphyllaceae). These unusual ring systems have been challenging targets for total synthesis as well as biosynthetic studies. We have isolated novel types of Daphniphyllum alkaloids from Daphniphyllum macropodum, D. humile, D. teijsmanni, and D. glaucescense. In our continuing search for structually unique and biogenetically interesting new alkaloids, calyciphyllines C-G (1-5) have been isolated from D. calycinum, and their structures and relative stereochemistry were elucidated on the basis of spectroscopic data. Calyciphylline C (1) is a novel Daphniphyllum alkaloid with an unprecedented fused-hexacyclic skeleton having an azetidine ring. Calyciphyllines D (2) and F (4) are novel alkaloids containing a unique fused-pentacyclic skeleton with a 8-azatricyclo[4.2.1.0.^<4,8>]nonane ring system. Calyciphylline E (3) is a new alkaloid with a fused-heptacyclic ring system, while calyciphylline G (5) is a novel alkaloid possessing an unprecedented fused-hexacyclic skeleton containg 5-azatricyclo[6.2.1.0]undecane ring system. Effects of these alkaloids on neurotrophic factor biosynthesis in 1321N1 human astrocytoma cells were examined by a semiquantitative RT-PCR method to find that the mRNA expressions for NGF were enhanced.

DOI： 10.24496/tennenyuki.49.0_271

ケミカルバイオロジー研究のフロンティア創薬リードとしての分子標的天然薬物の探索

小林淳一, 久保田高明

現代化学 ( 436 ) 21-26 - 26 2007.7

創薬リードとしての分子標的天然薬物の探索

小林淳一, 久保田高明

現代化学 0 ( 436 ) 21 - 26 2007.7

渦鞭毛藻由来の新規amphidinolide関連化合物の構造

高橋洋平, 久保田高明, 小林淳一

次世代を担う有機化学シンポジウム講演要旨集 5th 6-7 2007.5

免疫抑制物質brasilicardin Aの標的分子同定

臼井健郎, 臼井健郎, 南雲陽子, 南雲陽子, 渡邉愛, 久保田高明, 小林淳一, 長田裕之

日本農芸化学会大会講演要旨集 2007 98 2007.3

1 Agesamides and Nagelamides, Novel Bromopyrrole Alkaloids from Sponge Agelas spp.

Yasuda Tetsuro, Araki Atsushi, Tsuda Masashi, Kubota Takaaki, Fukushi Eri, Kawabata Jun, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 49 ( 0 ) 1 - 6 2007

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

Diffusion-ordered NMR spectroscopy (DOSY) is a versatile and powerful NMR technique and a noninvasive analytical method for mixture analysis that does not require prior physical separation of the analysis. In our search for new metabolites from natural resources, DOSY was applied for constituent analysis of crude bromopyrrole fractions separated from an Okinawan marine sponge Agelas sp. (SS-1056) so that two new bromopyrrole alkaloids, agesamides A (1) and B (2), have been isolated. The structures and relative stereochemistry of 1 and 2 were elucidated fromspectroscopic data. Furthermore, two new bromopyrrole alkaloids, nagelamides J (3) and K (4), have been isolated from another Okinawan marine sponge Agelas sp. (SS-1077), and the structures and relative stereochemistries were elucidated from spectroscopic data. Nagelamide J (3) is the first bromopyrrole alkaloid possessing a cyclopentane ring fused to an amino imidazole ring and nagelamide K (4) is a unique dimeric bromopyrrole alkaloid containing an ester linkage. Nagelamide J (3) exhibited antimicrobial activity against Staphylococcus aureus (MIC, 8.35μg/ml) and antifungal activity against Cryptococcus neoformans (MIC, 16.7μg/ml), while nagelamide K (4) exhibited antimicrobial activity against Micrococcus luteus (MIC, 16.7μg/ml).

DOI： 10.24496/tennenyuki.49.0_1

1 Agesamides and Nagelamides, Novel Bromopyrrole Alkaloids from Sponge Agelas spp.

Yasuda Tetsuro, Araki Atsushi, Tsuda Masashi, Kubota Takaaki, Fukushi Eri, Kawabata Jun, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 49 ( 0 ) 1 - 6 2007

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

DOI： 10.24496/tennenyuki.49.0_1

STRUCTURES AND PLAUSIBLE BIOGENETIC PATHWAY FOR NOVEL ALKALOIDS FROM DAPHNIPHYLLUM SPECIES

MATSUNO YOSUKE, OKAMOTO MARIKO, ZAIMA KAZUMASA, KUBOTA TAKAAKI, KOBAYASHI JUN'ICHI, SHINZATO TAKAKAZU, MORITA HIROSHI

薬学雑誌 126 ( Suppl.5 ) 100-103 - 103 2006.11

ABSOLUTE STEREOCHEMISTRY AND MOLECULAR TARGET OF ANTITUMOR MACROLIDES, IEJIMALIDES

KUBOTA TAKAAKI, NOZAWA KOHEI, TSUDA MASASHI, ISHIYAMA HARUAKI, KAZAMI SAYAKA, USUI TAKEO, OSADA HIROYUKI, KOBAYASHI JUN'ICHI

薬学雑誌 126 ( Suppl.5 ) 222-225 2006.11

アスヒカズラLycopodium complanatum由来の新規アルカロイドの構造と生物活性

石内勘一郎, 久保田高明, 森田博史, 星野智洋, 小原祐太郎, 中畑則道, 小林淳一

天然有機化合物討論会講演要旨集 48th ( 48 ) 493-498 - 498 2006.9

Language：Japanese Publisher：Symposium on the chemistry of natural products

Club moss (Lycopodiaceae) is known to be a rich source of Lycopodium alkaloids posessing unique heterocyclic ring systems such as C_<16>N, C_<16>N_2, and C_<27>N_3, which have attracted great interest from biogenetic, synthetic, and biological points of view. In our continuing efforts to find new Lycopodium alkaloids, lycopladines A-D (1-4), lyconadin B (5), and complanadines C (6), D (7) were isolated from the club moss Lycopodium complanatum. The structures for 1-7 were elucidated on the basis of spectral data. Lycopladine A (1) obtained as colorless amourphous solid, showed the pseudomolecular ion peak at m/z 260 (M+H)^+ in the ESIMS, and the molecular formula, C_<16>H_<21>NO_2, was established by HRESIMS [m/z 260.1653, (M+H)^+, △+0.2mmu]. The gross structure of 1 was elucidated on the basis of 2D NMR data. The relative stereochemistry of 1 was elucidated from NOESY data. Lycopladine A (1) possesses an unprecedented skeleton different from known C_<16>N-type Lycopodium alkaloids. The stuructures of lycopladines B-D (2-4) were elucidated on the basis of spectroscopic data and modified Mosher's method. Lycopladine B (2) was 5-hydroxyl, △_<8,15>, △_<13,14>, and 17-methyl ester form of fawcettidane skeleton. Lycopladine C (3) was assigned as 5-O-acetyl form of 2. Lycopladine D (4) had fawcettidane skeleton with hydroxyl group at C-5 and lactone ring (C-13〜C-16). The absolute stereochemistry of 2 and 4 were elucidated by modified Mosher's method. The absolute configuration at C-5 of 2 and 4 were assigned to be S and R, respectively. Lyconadin B (5) was assigned as dihydro form of lyconadin A. Complanadines C (6) and D (7) were obtained as colorless amorphous solids. The structures and relative stereochmistry of 6 and 7 were elucidated on the basis of spectroscopic data. Complanadine C (6) was assigned as the dimer of 9-keto, △_<10,11> form of lycopodine and △_<9,10> form of lycopodine. The dimer of lycopodane skeleton has not been reported previously. Complanadine D (7) was tetrahydro form of complanadine A. A plausible biogenetic path of lyconadin A (8) was proposed on the basis of structure of lycopladine A (1). Biogenetically, lyconadines A (8) and B (5) might be derived from L-lysine via pelletierine, phlegmarane skeleton, and an intermediate X from which lycopladine A (1) might be provided. Effects of lycopladines A-D (1-4), and lyconadins A (8) and B (5) on neurotrophic factor biosynthesis in 1321N1 human astrocytoma cells were examined. The mRNA expressions of NGF in 1321N1 cells were examined by a semiquantitative RT-PCR method. The mRNA expressions for NGF were enhanced by lyconadins A (8) and B (5).

DOI： 10.24496/tennenyuki.48.0_493

P-16 Structures and Biological Activity of New Lycopodium Alkaloids from Lycopodium complanatum

Ishiuchi Kan'ichiro, Kubota Takaaki, Morita Hiroshi, Hoshino Tomohiro, Obara Yutaro, Nakahata Norimichi, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 0 ( 48 ) 493 - 498 2006.9

Language：Japanese Publisher：Symposium on the chemistry of natural products

DOI： 10.24496/tennenyuki.48.0_493

沖縄産ホヤ由来マクロリド・イエジマリド類の構造と生物活性 (第16回天然薬物の開発と応用シンポジウム講演要旨集)

ヒメユズリハ(Daphniphyllum teijsmannii)より単離した新規アルカロイドDaphtenidine A‐Dの構造

松野陽介, 松野陽介, 久保田高明, 森田博史, 新里孝和, 関口光広, 小林淳一

日本生薬学会年会講演要旨集 53rd 152 - 152 2006.9

アスヒカズラLycopodium complanatum由来の新規アルカロイドの構造と生物活性

石内勘一郎, 久保田高明, 小林淳一, 森田博史, 星野智洋, 小原祐太郎, 中畑則道

日本生薬学会年会講演要旨集 53rd 157 2006.9

放線菌由来細胞毒性物質・ブラシリカルジン類の構造と活性

小林淳一, 久保田高明

日本癌学会学術総会記事 65th 466-467 2006.8

リコポジウムアルカロイドの構造の多様性と生物活性

石内勘一郎, 久保田高明, 小林淳一, 森田博史

万有生命科学振興国際交流財団札幌シンポジウム 18th 42 2006.7

Promising V-ATPase Inhibitors as Drugs for Treatment of Osteoporosis and Tumor.

KOBAYASHI JUN'ICHI, KUBOTA TAKAAKI

化学 61 ( 6 ) 68-69 2006.6

沖縄産海綿Cribrochalina sp.より単離した新規ピリジンアルカロイドPyrinadine Aの構造

久保田高明, 仮屋佑子, 小林淳一

日本薬学会年会要旨集 126th ( 4 ) 86 2006.3

Iejimalidesの標的分子の同定

風見紗弥香, 臼井健郎, 室井誠, 久保田高明, 小林淳一, 長田裕之

日本農芸化学会大会講演要旨集 2006 11 2006.3

久保田高明, 野沢耕平, 津田正史

薬学雑誌 126 ( 0 ) 222 - 225 2006

海洋渦鞭毛藻由来の新規ポリケチドの探索

久保田高明, 佐久間裕介, 新保和高, 津田正史, 小林淳一

マリンバイオテクノロジー学会大会講演要旨集 8th 109 2005.5

27 Structure Elucidation and Biosynthetic Studies of Amphezonol A, a Novel Polyhydroxyl Metabolite from Symbiotic Marine Microalga

Kubota Takaaki, Sakuma Yusuke, Shimbo Kazutaka, Tsuda Masashi, Uozumi Yasuhiro, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 47 ( 0 ) 151 - 156 2005

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

Amphezonol A (1), a novel polyhydroxyl compound, was isolated from a marine dinoflagellate Amphidinium sp. (Y-72), and the structure was elucidated on the basis of 2D NMR data including HSQC-TOCSY and INADEQUATE spectra (920MHz) using the ^<13>C-enriched sample. Amphezonol A (1), C_<62>H_<114>O_<24>, was the first member of a new class of polyketide natural products consisting of a C_<60>-linear aliphatic chain with twenty-one hydroxyl groups, and two tetrahydropyran and a tetrahydrofuran rings. Cloning of polyketide synthase (PKS) gene from a dinoflagellate Amphidinium sp. was attempted and PKS gene fragments were obtained by PCR amplification from degenerated primer sets designed on the basis of the conserved amino acid sequences in known type I PKSs. The PCR analysis, using primer sets designed from these PKS gene fragments, revealed that these DNA sequences exist only in the dinoflagellates producing polyketides.

DOI： 10.24496/tennenyuki.47.0_151

27 Structure Elucidation and Biosynthetic Studies of Amphezonol A, a Novel Polyhydroxyl Metabolite from Symbiotic Marine Microalga

Kubota Takaaki, Sakuma Yusuke, Shimbo Kazutaka, Tsuda Masashi, Uozumi Yasuhiro, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 47 ( 0 ) 151 - 156 2005

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

DOI： 10.24496/tennenyuki.47.0_151

Absolute Stereochemistry of Amphidinolide E.

KUBOTA TAKAAKI, TSUDA MASASHI, KOBAYASHI JUN'ICHI

日本化学会講演予稿集 81st ( 2 ) 707 2002.3

Studies on biosynthesis of amphidinolides.

TSUDA MASASHI, KUBOTA TAKAAKI, SHIMBO KAZUTAKA, HORIGUCHI TAKEO, KATSUMATA KAZUHITO, KOBAYASHI JUN'ICHI

日本化学会講演予稿集 80th 3 2001.9

沖縄産海綿Suberea sp.より単離した新規ブロモチロシンアルカロイドMa′edamine AとBの構造

久保田高明, 津田正史, 平野敬子, 渡部賢二, 小林淳一

日本薬学会年会要旨集 121年会 ( 2 ) 119 - 119 2001.3

17 Stereochemistry of Amphidinolides C and T1〜T5

Kubota Takaaki, Tsuda Masashi, Endo Tetsuya, Shiro Motoo, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 43 ( 0 ) 97 - 102 2001

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

Amphidinolide C (1) is a unique 25-membered macrolide isolated from a marine dinoflagellate Amphidinium sp. (strain Y-5). The gross structure of 1 has been elucidated by 2D-NMR data, whereas the stereochemistry remains undefined. During our search for bioactive metabolites from marine dinoflagellates, relatively large amounts of 1 have been recently isolated from two strains (Y-56 and Y-71) of the genus Amphidinium, which allowed us to investigate the stereochemistry of 1 Absolute configurations at C-12, C-13, C-20, C-23, C-24, and C-29 of amphidinolide C (1) were assigned by combination of NMR analyses including J-based configuration analysis and Mosher's method, while absolute configurations at C-7 and C-8 of 1 were assigned by application of Mosher's method for erythro glycol and comparison of ^1H-NMR data of natural specimen with those of synthetic C-1-C-10 segments. Absolute configurations at C-3, C-4, C-6, and C-16 of 1 were elucidated by comparison of NMR data of degradation products of 1 with synthetic C-1-C-7 and C-16-C-18 segments. On the other hand, five new 19-membered macrolides amphidinolides T1-T5 (2-6) have been isolated from the Y-56 and Y-71 strains of the genus Amphdinium. The gross structures were elucidated by 2D-NMR analyses. Absolute configurations at C-2, C-13, C-14, and C-18 of amphidinolide T1 (2) were assigned on the basis of NMR data of the MTPA esters of 2 and those of degradation products of 2, while absolute configurations at C-7, C-8, and C-10 of 2 were elucidated by comparison of ^1H-NMR data of C-1-C-12 segment with those of synthetic model compounds for tetrahydrofuran portion. The absolute stereochemistry of amphidinolides T2-T5 (3-6) were also elucidated by similar methods. The stereostructure of 2 was also confirmed by a single crystal X-ray diffraction analysis.

DOI： 10.24496/tennenyuki.43.0_97

17 Stereochemistry of Amphidinolides C and T1〜T5

Kubota Takaaki, Tsuda Masashi, Endo Tetsuya, Shiro Motoo, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 43 ( 0 ) 97 - 102 2001

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

DOI： 10.24496/tennenyuki.43.0_97

Two New Cyclic Depsipeptides from Okinawan Marine Sponge Theonella sp.

SHIMBO KAZUTAKA, KUBOTA TAKAAKI, TSUDA MASASHI, KOBAYASHI JUN'ICHI

日本化学会講演予稿集 78th ( 2 ) 849 2000.3

Amphidinolide V, Novel 14-Membered Macrolide from Marine Dinoflagellate Amphidinium sp.

KUBOTA TAKAAKI, TSUDA MASASHI, KOBAYASHI JUN'ICHI

日本化学会講演予稿集 78th ( 2 ) 884 2000.3

100(P48) Colopsinols A and B, Novel Polyhydroxyl Metabolites from Marine Dinoflagellate Amphidinium sp.

Kubota Takaaki, Tsuda Masashi, Takahashi Miho, Ishibashi Masami, Kobayashi Jun'ichi, Naoki Hideo

Symposium on the Chemistry of Natural Products, symposium papers 41 ( 0 ) 595 - 600 1999

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

Marine dinoflagellates of the genus Amphidinium have been recognized as a rich source of novel bioactive substances with unique structures. We previously isolated a series of cytotoxic macrolides, designated amphidinolides, possessing unique structural features from several strains of the dinoflagellates Amphidinium sp., among which the strain Y-5 was the richest source of the amphidinolides. Further search for metabolites from the strain Y-5, which was a symbiont of Okinawan marine acoel flatworm Amphiscolops sp., resulted in the isolation of two novel polyhydoroxyl compounds, colopsinols A (1) and B (2), belonging to a new class of polyketide metabolites. The structures of 1 and 2 were elucidated on the basis of extensive NMR techniques including a newly developed 2D NMR experiments such as CH_2-selected editing HSQC (E-HSQC) as well as FABMS/MS data. Colopsinols A (1) and B (2) are new class of polyketide natural products consisting of C_<56> and C_<53>-liner carbon chains, respectively, possessing a gentiobioside (β-D-glucopyranosyl-(1-6)-β-D-glucopyranoside) moiety and a sulfate ester. From this strain (Y-5), 13 cytotoxic macrolides, amphidinolides A-D, J, K, and M-S, have been isolated so far. Biosynthetically it is interesting that quite different type of polyketides such as colopsinols and amphidinolides are produced from the same dinoflagellate. Colopsinol A (1) showed inhibitory activity against DNA polymerase α and β with IC_<50> values of 13 and 7μM, respectively.

DOI： 10.24496/tennenyuki.41.0_595

100(P48) Colopsinols A and B, Novel Polyhydroxyl Metabolites from Marine Dinoflagellate Amphidinium sp.

Kubota Takaaki, Tsuda Masashi, Takahashi Miho, Ishibashi Masami, Kobayashi Jun'ichi, Naoki Hideo

Symposium on the Chemistry of Natural Products, symposium papers 41 ( 0 ) 595 - 600 1999

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

DOI： 10.24496/tennenyuki.41.0_595

Structure of new polyol compound Luteophanol B isolated from Gonyaulax Amphidinium species.

KUBOTA TAKAAKI, TSUDA MASAFUMI, DOI YUKIKO, NAKAMICHI HIROKO, ISHIBASHI MASAMI, KOBAYASHI JUN'ICHI

日本薬学会年会要旨集 118th ( 2 ) 108 1998.3

80(P63) Luteophanols B and C, New Polyhydroxyl Compounds from Marine Dinoflagellate

Kubota Takaaki, Tsuda Masashi, Doi Yukiko, Takahashi Ayako, Nakamichi Hiroko, Ishibashi Masami, Fukushi Eri, Kawabata Jun, Kobayashi Jun'ichi

Symposium on the Chemistry of Natural Products, symposium papers 40 ( 0 ) 473 - 478 1998

Language：Japanese Publisher：Symposium on the Chemistry of Natural Products Steering Committee

During our continuing search for structurally unique secondary metabolites from marine dinoflagellates, we previously isolated a series of cytotoxic macrolides, amphidinolides, from dinoflagellates Amphidinium sp. Recently we investigated another strain of Amphidinium sp. (strain number Y-52), which was isolated from the inside cells of the Okinawan marine acoel flatworm Pseudaphanostoma luteocoloris, and isolated two new polyhydroxyl compounds, luteophanols B (1) and C (2), both consisting of a C_<64>-linear aliphatic chain. The structure elucidation of 1 and 2 were elucidated on the basis of chemical degradation and newly developed 2D NMR experiments, E-HSQC and E-HSQC-TOCSY. E-HSQC and E-HSQC-TOCSY are very useful techniques for structure elucidations of complex natural products possessing many aliphatic methine and methylene carbons such as luteophanols B (1) and C (2). CH_2-selected E-HSQC-TOCSY^6 experiments seem to be suitable to assign very closely resonated carbon signals, since this method affords the high resolution in F_1 axis by limiting the F_1 spectral width, in which sp^2 methylene carbons are resonated.

DOI： 10.24496/tennenyuki.40.0_473