著者

海原 浩辰 林 尚毅 横島 聡 藤間 達哉 井上 将行 福山 透

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 第59回天然有機化合物討論会実行委員会 (ISSN:24331856)

巻号頁・発行日

pp.163-168, 2017 (Released:2020-09-20)

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Asymmetric total synthesis of (–)-morphine (1) has been accomplished in 18 steps from commercially available 7-methoxy-2-tetralone (7). Our synthesis features a simple transformation from the readily available chiral intermediate (3), reported earlier by d’Angelo and co-workers. Introduction of the requisite oxygen functionality to the 8-position of the tetralone could be achieved by Friedel-Crafts acylation and ensuing Baeyer-Villiger oxidation. Upon treatment of dienol 15 with acid at 0 °C, a facile cyclization proceeded to form the E-ring (16). The diene thus formed was later converted to γ-hydroxy-α,β-unsaturated ketone 20 by means of photooxygenation and triethylamine. Dehydration of 20 was effected by triflic anhydride and subsequent removal of 2,4-dinitrobenzenesulfonyl group generated a mixture of neopinone (21) and codeinone (22). Conversion of the mixture to (–)-morphine was performed by following the known procedures.

著者

永井 宏史 五十嵐 文子 北谷 龍樹 内田 肇 渡邊 龍一 鈴木 敏之 Masoud Shadi Sedghi 長澤 和夫

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 第59回天然有機化合物討論会実行委員会 (ISSN:24331856)

巻号頁・発行日

pp.585-590, 2017 (Released:2020-09-20)

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Jellyfish, sea anemone and coral are classified as members of the phylum Cnidaria. All cnidarians have a stinging cell, cnidocyte, and its stinging organelle nematocysts. Nematocyst stores venom and coiled needle inside and discharge the needle and inject venom into their prey. Both physical and chemical stimuli trigger nematocyst discharge. A lot of studies on the venom of cnidarians have been accomplished. As the results, it has been revealed that most of cnidarian venoms consisted of proteinaceous toxins. However, there are few studies on the low molecular weight compounds from the cnidarian nematocysts. Therefore, we started the search of low molecular weight compounds in the nematocyst. First target was the venomous jellyfish Chironex yamaguchii (Habu-kurage in Japanese). Nematocysts were isolated from C. yamaguchii tentacles. The isolated nematocyst and C. yamaguchii tentacle without nematocyst were extracted with 1 M NaCl solution using a mini-bead beater machine. The extracts were screened with LC-MS. It was clearly shown that three compounds all of which have [M+H]+ 517 were existed especially in nematocysts. Three compounds were isolated with HPLCs. NMR and MS spectra data of isolated compounds revealed their planar structure as cyclic γ-tetra glutamic acids. The determination of absolute stereochemistry of these compounds was established with organic synthesis, comparing optical rotation values and Marfey’s analysis. Three cyclic γ-tetra glutamic acids were designated as cnidarin4A (1a), cnidarin4B (1b) and cnidarin4C (1c), respectively. Cnidarin4A and cnidarin4B were new compounds. Cnidarin4C was first obtained as the natural product in this study. The existence of these compounds in marine animals has been studied using LC-MS. Cnidarin4s were detected from all the nine tested cnidarians, on the contrary no cnidarin4s were detected from all the seven tested the other phylum animals. Cnidarin4s are especially existed in animals of the phylum Cnidaria. The ecological role of cnidarin4s in cnidarians is a challenging subject to be elucidated.