- Total syntheses of (+)-sesamin and (+)-sesaminol
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Total syntheses of (+)-sesamin (1a ) and (+)-sesaminol (1b), which are major components of sesame lignans derived from Sesamum indicum, were accomplished in a highly stereo-controlled manner. Key steps include an L-proline-catalyzed cross-a ldol reaction, which was accelerated with the aid of bifunctional urea 7, and the construction of a furofuran lignan skeleton through a quinomethide intermediate.
- Ishikawa, Ryo,Yoshida, Naoto,Akao, Yusuke,Kawabe, Yusuke,Inai, Makoto,Asakawa, Tomohiro,Hamashima, Yoshitaka,Kan, Toshiyuki
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- Stable Axially Chiral Isomers of Arylnaphthalene Lignan Glycosides with Antiviral Potential Discovered from Justicia procumbens
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Arylnaphthalene lignans (ANLs) were known to have axial chirality due to the biphenyl skeleton with hindered rotation at the single bond. However, the stable ANL atropisomers have not been isolated from nature until the present study. Phytochemical separation of the methanol extract of the stems and barks of Justicia procumbens led to the isolation of 11 ANL glycosides including four pairs of new atropisomers with stable confirmations at room temperature. Their structures were deduced from elucidation of the extensive spectral data, and their absolute configurations were determined by the circular dichroism, electronic circular dichroism, and X-ray methods as well as the total synthesis of one pair of the atropisomers. The ANL compounds were evaluated for their antiviral potential, and it was found that they displayed great antiviral activity discrepancy between a pair of atropisomers due to the geometric orientation. The 1′P-oriented atropisomers showed much more significant antiviral potency than their corresponding 1′M-oriented counterparts. The biological activity discrepancy caused by the axial chirality will not only inspire synthetic design of novel ANL atropisomers to enrich the structural diversity, but also provide important hints to direct the synthetic approaches toward the antiviral drug development of ANL compounds.
- Zhao, Yang,Ku, Chuen-Fai,Xu, Xin-Ya,Tsang, Nga-Yi,Zhu, Yu,Zhao, Chen-Liang,Liu, Kang-Lun,Li, Chuang-Chuang,Rong, Lijun,Zhang, Hong-Jie
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p. 5568 - 5583
(2021/05/07)
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- Stereocontrolled total syntheses of optically active furofuran lignans
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Plant products (+)-sesamin, (+)-sesaminol, (+)-methylpiperitol, (+)-aschantin, and (+)-5'-hydroxymethylpiperitol were synthesized in a highly stereocontrolled manner through l-proline-catalyzed bifunctional-urea-accelerated cross-aldol reaction, followed by biomimetic construction of the furofuran lignan skeleton through a quinomethide intermediate.
- Inai, Makoto,Ishikawa, Ryo,Yoshida, Naoto,Shirakawa, Nana,Akao, Yusuke,Kawabe, Yusuke,Asakawa, Tomohiro,Egi, Masahiro,Hamashima, Yoshitaka,Kan, Toshiyuki
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p. 3513 - 3521
(2015/11/17)
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- Total synthesis of 60-hydroxyjusticidin A
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The first total synthesis of 6′-hydroxyjusticidin A, isolated from Justicia procumbens L. with good inhibitory activity against cancer cells, has been accomplished. The structure was confirmed by 1H NMR, 13C NMR, and HR-ESI-MS. The key steps involved a Diels-Alder cycloaddition reaction and a reduction in NaBH4.
- Xiong, Lu,Bi, Ming-Gang,Wu, Song,Tong, Yuan-Feng
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p. 322 - 326
(2012/08/28)
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- N-ACYL ANTHRANILIC ACID DERIVATIVE OR SALT THEREOF
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An N-acyl anthranilic acid derivative represented by general formula (1) or a salt thereof is useful for prevention or treatment of diseases associated with excessive production of collagen. (In the formula, R1 represents a carboxyl group or th
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Page/Page column 40-41
(2011/11/13)
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- Asymmetric total synthesis of (+)-pisatin, a phytoalexin from garden peas (Pisum sativum L.)
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A short asymmetric total synthesis of (+)-pisatin is described involving a Sharpless asymmetric dihydroxylation and an 'hydrogenative cyclisation' as key steps.
- Pinard, Emmanuel,Gaudry, Michel,Henot, Frederic,Thellend, Annie
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p. 2739 - 2742
(2007/10/03)
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- Regioselective Synthesis of Prenylisoflavones. Syntheses of Lupiwighteone, Lupiwighteone Hydrate and Related Compounds
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The palladium-catalyzed coupling reaction of 4',5.7-tris(benzyloxy)-8-iodoisoflavone 11, synthesized from the 3'-iodochalcone 8, with 2-methyl-3-butyn-2-ol gave the corresponding 8-(3-hydroxy-3-methylbutynyl)isoflavone 12.Catalytic hydrogenation of 12 gav
- Tsukayama, Masao,Li, He,Nishiuchi, Masaki,Takahashi, Masahumi,Kawamura, Yasuhiko
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p. 1181 - 1196
(2007/10/03)
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- Synthetic approaches toward ecteinascidins. Part 1. Preparation of an (E)-2-arylidene-3-benzyl-1,5-imino-3-benzazocin-4-one having a protected phenol in the E-ring
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A synthetic strategy for the preparation of ecteinascidins isolated from the Caribbean tunicate Ecteinascidia turbinata and an efficient synthesis of a key tricyclic lactam intermediate 32 are described.The key step is the intramolecular cyclization of the allylic alcohol 15 to the (E)-1,5-imino-3-benzazocine 16.Cyclization of 15 (R = Me, Bn) afforded the desired product 16 in good yield.However, treatment of 15 (R = MOM) under acidic conditions gave compound 18 in high yield, the structure of which was determined by X-ray crystallography.Finally, 16 was converted into (E)-N-methyltricyclic lactam 32 that can serve as a synthetic precursor of ecteinascidins.
- Saito, Naoki,Tashiro, Kyoichi,Maru, Yukie,Yamaguchi, Kentaro,Kubo, Akinori
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