研究者詳細 - 久保田　高明

P-33 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(ポスター発表の部)

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 0 ( 50 ) 361 - 366 2008年9月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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年9月

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年9月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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年9月

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年3月

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年3月

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年3月

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年3月

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年3月

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年9月

P-11 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(ポスター発表の部)

齊藤静夏, 久保田高明, 福士江里, 川端潤, 張恵平, 小林淳一

天然有機化合物討論会講演要旨集 0 ( 49 ) 271 - 276 2007年8月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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年8月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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年7月

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年7月

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年5月

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年3月

1 Agelas属海綿由来の新規アルカロイドagesamide類およびnagelamide類の構造(口頭発表の部)

安田鉄郎, 荒木敦, 津田正史, 久保田高明, 福士江里, 川端潤, 小林淳一

天然有機化合物討論会講演要旨集 49 ( 0 ) 1 - 6 2007年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

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 Agelas属海綿由来の新規アルカロイドagesamide類およびnagelamide類の構造(口頭発表の部)

安田鉄郎, 荒木敦, 津田正史, 久保田高明, 福士江里, 川端潤, 小林淳一

天然有機化合物討論会講演要旨集 49 ( 0 ) 1 - 6 2007年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

DOI： 10.24496/tennenyuki.49.0_1

ユズリハ科植物(Daphniphynaceae)に含まれる新規アルカロイドの構造と推定生合成経路

松野陽介, 岡本麻里子, 在間一将, 久保田高明, 小林淳一, 新里孝和, 森田博史

薬学雑誌 126 ( Suppl.5 ) 100-103 - 103 2006年11月

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

久保田高明, 野沢耕平, 津田正史, 石山玄明, 風見紗弥香, 臼井健郎, 長田裕之, 小林淳一

薬学雑誌 126 ( Suppl.5 ) 222-225 2006年11月

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年9月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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 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(ポスター発表の部)

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 0 ( 48 ) 493 - 498 2006年9月

記述言語：日本語出版者・発行元：天然有機化合物討論会

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年9月

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年9月

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年8月

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年7月

骨粗鬆症やがんの治療薬として期待のV‐ATPase阻害剤

小林淳一, 久保田高明

化学 61 ( 6 ) 68-69 2006年6月

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年3月

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年3月

久保田高明, 野沢耕平, 津田正史

薬学雑誌 126 ( 0 ) 222 - 225 2006年

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年5月

27 海洋共生藻由来の新規長鎖ポリヒドロキシ化合物Amphezonol Aの構造と生合成研究(口頭発表の部)

久保田高明, 佐久間祐介, 新保和高, 津田正史, 魚住泰広, 小林淳一

天然有機化合物討論会講演要旨集 47 ( 0 ) 151 - 156 2005年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

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 海洋共生藻由来の新規長鎖ポリヒドロキシ化合物Amphezonol Aの構造と生合成研究(口頭発表の部)

久保田高明, 佐久間祐介, 新保和高, 津田正史, 魚住泰広, 小林淳一

天然有機化合物討論会講演要旨集 47 ( 0 ) 151 - 156 2005年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

DOI： 10.24496/tennenyuki.47.0_151

Amphidinolide Eの立体化学

久保田高明, 津田正史, 小林淳一

日本化学会講演予稿集 81st ( 2 ) 707 2002年3月

Amphidinolide類の生合成に関する研究

津田正史, 久保田高明, 新保和高, 堀口健雄, 勝又和人, 小林淳一

日本化学会講演予稿集 80th 3 2001年9月

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年3月

17 Amphidinolide CおよびT1〜T5の立体構造(口頭発表の部)

久保田高明, 津田正史, 遠藤哲哉, 城始勇, 小林淳一

天然有機化合物討論会講演要旨集 43 ( 0 ) 97 - 102 2001年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

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 Amphidinolide CおよびT1〜T5の立体構造(口頭発表の部)

久保田高明, 津田正史, 遠藤哲哉, 城始勇, 小林淳一

天然有機化合物討論会講演要旨集 43 ( 0 ) 97 - 102 2001年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

DOI： 10.24496/tennenyuki.43.0_97

沖縄産海綿Theonella sp.より単離した新規環状デプシペプチドの構造

新保和高, 久保田高明, 津田正史, 小林淳一

日本化学会講演予稿集 78th ( 2 ) 849 2000年3月

渦鞭毛藻Amphidinium sp.より単離した新規14員環マクロリドAmphidinolide Vの構造

久保田高明, 津田正史, 小林淳一

日本化学会講演予稿集 78th ( 2 ) 884 2000年3月

100(P48) 渦鞭毛藻Amphidinium sp.より単離した新規ポリヒドロキシ化合物Colopsinol AとBの構造(ポスター発表の部)

久保田高明, 津田正史, 高橋美穂, 石橋正己, 小林淳一, 直木秀夫

天然有機化合物討論会講演要旨集 41 ( 0 ) 595 - 600 1999年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

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) 渦鞭毛藻Amphidinium sp.より単離した新規ポリヒドロキシ化合物Colopsinol AとBの構造(ポスター発表の部)

久保田高明, 津田正史, 高橋美穂, 石橋正己, 小林淳一, 直木秀夫

天然有機化合物討論会講演要旨集 41 ( 0 ) 595 - 600 1999年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

DOI： 10.24496/tennenyuki.41.0_595

渦鞭毛藻Amphidinium sp.より単離した新規ポリオール化合物Luteophanol Bの構造

久保田高明, 津田正史, 土居由貴子, 中道寛子, 石橋正己, 小林淳一

日本薬学会年会要旨集 118th ( 2 ) 108 1998年3月

80(P63) 渦鞭毛藻由来の新規ポリヒドロキシ化合物Luteophanol BおよびCの構造(ポスター発表の部)

久保田高明, 津田正史, 土居由貴子, 高橋彩子, 中道寛子, 石橋正己, 福士江里, 川端潤, 小林淳一

天然有機化合物討論会講演要旨集 40 ( 0 ) 473 - 478 1998年

記述言語：日本語出版者・発行元：天然有機化合物討論会実行委員会

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