著者

西沢 麦夫

出版者

The Society of Synthetic Organic Chemistry, Japan

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.51, no.7, pp.631-640, 1993-07-01 (Released:2010-01-28)

参考文献数

51

被引用文献数

1 2

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Significant attentions have been focused on the inclusion chemistry of cyclodextrins and the related compounds and synthetic studies of cyclooligosaccharides have been tarring out intensively. For example, Ogawa and coworkers reported the total synthesis of cyclodextrins and a manno isomer of cyclodextrins by means of phenylselenyl triflate promoted cycloglycosylations. Synthesis of 1-3β linked cycloglucohexaose was reported by Collins' group. Modifications of α-cyclodextrin into trimethyl, 1, 3-anhydro, and a chimera analog have also reported recently. However, cyclooligosaccharide available today is only limited to D series. As we have developed a novel thermal glycosylation procedure, which can be applied to rhamnosylation with high α-selectivity, we designed the synthesis of cyclo-L-rhamnohexaose (40), the first cyclooligosaccharide of L series. On the basis of the area where the compound has been prepared, this compound was named α-cycloawaodorin, which would open a new dimension of the inclusion chemistry.

著者

目 武雄 藤野 明 村井 不二男 鈴井 明男 仏願 保男 西沢 麦夫

出版者

天然有機化合物討論会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

no.50, pp.19-24, 2008-09-01

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Matatabi (Actinidia polygamy Miq., Actinidiaceae) is widely distributed in this country. It is well known from early times that the leaf, the fruit, and the root of this plant show special biological activity in Felidae animals. Although significant chemical studies were carried out, the isolation and structure elucidation of the active principles were not reported until 1959. We isolated two active principles from the methanol extract of the leaf and the fruit of matatabi, a lactone C_<10>H_<16>O_2 named matatabilactone (1), and a base C_<10>H_<13>N named actinidine (2), in 0.0035 and 0.12% yield, respectively. Herein the structure study and the synthesis of 1 and 2 will be discussed.

著者

中野 真代 小田 真隆 永浜 政博 山本 博文 今川 洋 櫻井 純 西沢 麦夫 樽井 敬史 渋谷 昌弘 大林 寿美代 玉城 翔太

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

vol.54, pp.333-338, 2012

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Vizantine (3) is a synthetic derivative of treharose-6,6-dicorynomycolate (TDCM) which was characterized in 1993 as the cell surface glycolipid of Corynebacterium diphtheriae and shows a variety of significant biological activities for adjuvant development. In vitro, vizantine activates not only the macrophages of mice sera, but also induces the release of MIP-1β, IL-6, IL-8 etc. from human acute monocytic leukemia cell line cells (THP-1 cells). Because almost no TNF-α is induced in vivo, the lethal toxicity to animals was found to be ncredibly low. However, oral administration of vizantine to C57BL/6 mouse (p.o. 100 μg x 7 times) inhibits lung metastasis of B16-BL6 melanoma cells (which are classified in highly metastatic tumor cell). In recent years, structural components of the outer surface membrane of bacteria have attracted considerable attention as lead compounds for adjuvant development. However, a concern of the use of these compounds is that they can over-activate innate immune responses leading to the clinical symptoms of septic shock. Therefore, an important issue is a detailed knowledge of the immunostimulatory mechanism to harness beneficial effects without causing toxicity. Here, to advance the mechanistic studies of vizantine, we have synthesized magnetic beads-attached 4 that maintain immunological activities and can therefore act as a molecular probe. Using a pull-down assay of 4 and the extract of HEK-293T cells transfected with plasmid for TLR4 and MD2, vizantine was found to act as a ligand of the Toll-like receptor 4 (TLR4) and MD2 complex. Furthermore, the macrophage from TLR4 knockout (TLR4 -/-) mice showed decreased response to vizantine, but that from TLR2 knockout (TLR2 -/-) mice did not. Taken together the results suggest that vizantine suppresses the tumor lung metastasis through the activation of macrophages via TLR4/MD2 complex.

著者

杉原 多公通 山口 雅彦 西沢 麦夫

出版者

社団法人 有機合成化学協会

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.57, no.3, pp.158-169, 1999-03-01 (Released:2009-11-16)

参考文献数

23

被引用文献数

5 7

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Cyclic cotrimerization of an alkyne, an alkene, and carbon monoxide mediated by dicobalt octacarbonyl, which is well known as the Pauson-Khand reaction, was promoted by the addition of certain Lewis bases. Primary amines with secondary alkyl groups, such as cyclohexylamine, promoted the stoichiometric Pauson-Khand reaction to give the desired cyclopentenones in good yields. The same reaction can be conveniently carried out in 1, 4-dioxane-aqueous NH4OH biphasic system. Some reactive cobalt complexes might be produced as the coproduct in the reaction mixture and decomposed the substrate and/or the product in some cases. To overcome this disadvantage, alkyl methyl sulfides were introduced as the promoter. The catalytic Pauson-Khand reaction was also promoted by the addition of a tiny amount of DME or water. A novel decomplexation method of alkyne-dicobalt hexacarbonyl complexes by using ethylenediamine and a hydrocarbamoylation reaction were also presented.

著者

西沢 麦夫 山田 英俊

出版者

公益社団法人日本薬学会

雑誌

ファルマシア (ISSN:00148601)

巻号頁・発行日

vol.29, no.8, pp.867-872, 1993-08-01

被引用文献数

1

著者

西沢 麦夫 山田 英俊 林 雄二

出版者

天然有機化合物討論会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

no.28, pp.370-376, 1986-09-09

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A sweet principle of Phlomis betonicoides, baiyunoside (1a) reported by Tanaka, is a glycoside of 3-substituted furanoditerpene with labdane skeleton. During the series of our investigation dealing with a biomimetic olefin cyclization using mercury(III) triflate/N,N-dimethylaniline complex (2), we have examined the cyclization of some acyclic furano terpenoid, and observed that the cyclization of ambliofuran (3a) is mainly initiated from an internal double bond (Δ^<10>) to give 4 and 5, whereas the corresponding sulfone 3b affords terminal cyclization products 16, 17, and 18. The latter product 18 is a mixture of three isomeric olefins (Δ^<7,8>:Δ^<8,9>:Δ^<8,17>=9:4:3). Thus, the cyclization control of ambliofuran analog not only the initiation point but also the termination mode is essential in order to promote the selective total synthesis of (±)-baiyunol (1b), an aglycon of a sweet substance 1a. A furano ketone 3d is the best substrate to our purpose which gives Δ^<8,9> bicyclic product 28 in high yield. The resulting organomercuric ketone 28 is efficiently transformed to 1b, and which is identified with (+)-baiyunol derived from natural sweet glycoside. Glycosidation of (±)-baiyunol is currently undertaken.

著者

山田 英俊 西沢 麦夫

出版者

天然有機化合物討論会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

no.29, pp.349-355, 1987-07-25

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Sweet taste is one of the fascinating field of organic chemistry on the basis of social requirements to find low calorie and high quality taste. Baiyunoside (1) has been characterized as a sweet taste principle of chinese drug, Bai-Yun-Shen (Phlomis betonicoides), by Tanaka and co-workers along with the minor sweet glycoside named phlomisoside I (2). We have designed a general approach to this class of sweet glycosides in order to develop high quality artificial sweeteners. We have already reported an efficient total synthesis of (±)-baiyunol (4), the aglycon of 1 and 2 by means of selective olefin cyclization using mercury(II) triflate/N,N-dimethylaniline complex. We disclose herein the first total synthesis of baiyunoside (1) from (±)-baiyunol (4) via a novel 2' discriminated glycosidation using 2' free glycosyl halide. This novel glycosidation does not accompanied any oligosaccharide formation and this result suggests that very severe steric bulk exist at the newly formed 2' hydroxyl moiety of 6a. As is the case, 6a was entirely inert against a variety of Koenigs-Knorr type glycosidation in order to introduce the xylose moiety. However, Noyori's glycosidation based on a strong affinity between silicon and fluorine was efficiently applied to our purpose. When trimethylsilyl ether 16 was treated with fluorosugar 15 in toluene in the presence of catalytic amount of trimethylsilyl triflate afforded disaccharide 17 and 18 in 38: 62 ratio and in 58% yield. Deprotection of the latter afforded baiyunoside (1) and identified with natural product in every respects. Therefore, we have established a general way to prepare a wide variety of baiyunoside analogs in order to evaluate the taste.