天然有機化合物討論会講演要旨集

95 γ-ハロエステルの位置選択的開裂反応とその天然物合成への応用(ポスター発表の部)

内藤功一, 山根深一, 森和歌子, 鈴木幸夫, 本多利雄

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セッションID: 95
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_731

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Although development of the chemistry of samarium(II) iodide has been of continuing interest in organic synthesis, little attention has focused on the fragmentation reaction. During the course of our studies directed toward the synthesis of physiologically active natural products utilizing the cyclopentane derivative 1, readily accessible from a monoterpene, carvone, as a chiral starting material, we desired to develop an efficient method for the reductive carbon-carbon bond cleavage reaction regioselectively at the β-position to the ester function. The γ-bromo ester 9, prepared from the cyclopentane 8 by addition of hydrogen bromide in acetic acid, was treated with 3 equimolar amounts of samarium(II) iodide in THE and HMPA (20: 1, v/v) at ambient temperature to afford the desired olefin 10 in 48% yield. Reaction of the γ-chloro compound 12, derived from 8 by treatment with hydrogen chloride in ether, with samarium(II) iodide under the same reaction condition as above provided 10 in 77% yield. Treatment of other various y-halo carbonyl compounds with samarium(II) iodide gave the corresponding fragmentation products. The fragmentation reaction developed above was applied to the enantiospecific syntheses of (+)-eldanolide, a sex attractant pheromone, (-)-cis-whisky lactone known as one of the important flavors of whisky, brandy, and so on, and (-)-oudemansin A isolated from mycerial cultures of Oudemansiella mucida.

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96 インドラクタム類の立体配座 : 予測、実測および生物活性との関連(ポスター発表の部)

遠藤泰之, 大野道博, 平野祐明, 河合隆利, 竹田真由子, 板井昭子, 首藤紘一

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セッションID: 96
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_739

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Indolactam-V(2), which is a mininum structure for the appearance of tumor-promoting activity, has a nine-membered ring and amide bond. Indolactam-V exists in two conformational states in solution, SOFA and TWIST (1: 2 in CD_3OD). The conformation of the nine-membered ring depends on the substituents, and the relative positions of the hetero-atoms and orientations of hydrogen bonding which act significant roles on the recepter. High-temperature molecular dynamics (HTMD) calculation was performed on the simplest indolactam, indolactam-NS (6), in order to cover all the possible ring conformations. They were classified into ten independent ring conformations. In the case of indolactam-V and indolactam-TL (9), the coexistence of the TWIST and SOFA conformations were in good agreement with the calculations. Indolactam-G (7) exist the other conformation in solution and crystal structure, which was assigned FOLD conformation and that was in agreement with the calculation. We also examined the MD calculations, synthesis and conformational analysis by NMR of two designed compounds, methyl-substituted indolactams and simple lactams containing benzene ring.

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97 抗腫瘍活性環状ヘキサペプチドRA類の化学変換と構造活性相関(ポスター発表の部)

糸川秀治, 近藤和行, 一柳幸生, 森田博史, 竹谷孝一

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セッションID: 97
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_747

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A number of antitumor cyclic hexapeptide RA derivatives, including confomation-A and B locked models, were prepared from RA-II (8), RA-V (5), RA-VII (1) and RA-X-OMc (10) for structure-activity relationship studies. Evaluation of cytotoxicity of these compounds revealed that the methoxyl group on the aryl ring of Try3 greatly influenced the activities, while the substituents on the aryl ring of Tyr6 were less important for the activities. The amide bond between D-Alal and Ser2 of RA-III (25) was selectively cleaved via an oxazoline intermediate (28) to afford the seco-RA-III derivative (31). Inactiveness of the seco derivative against tumor cells revealed the importance of 18 membered ring structure, however the observations that the various ring modified derivatives including confomationally locked model compounds showed singnificant cytotoxicities suggested that further study was required for elucidating the biologically active confomation of RAs.

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98 エンジイン化合物の合成とDNA切断(ポスター発表の部)

堺恭大, 寒川克也, 渋谷雅之, 宍戸宏造

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セッションID: 98
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_755

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The new class of antitumor antibiotics esperamicins, calicheamicins, and dynemicin A have attracted considerable attention due to their very high biological activity as well as their potent DNA cleaving activities. We synthesized sulfur containing macrocyclic enediyne compounds (8,11,20,22 and 23) related to above antibiotics and studied on their radical producing reactions. Enediyne 8 and 11 required long reaction time and high temperature to aromatize under neutral conditions, whereas the sulfone 11 cyclized easily to afford benzenoid adduct 14 in the presence of basic catalysts.(table 1) The sulfone derivative 11 exhibited relatively potent activities depending on the drug concentration, reaction time, and pH. In order to develop more powerful agents, we synthesized the hydroxy derivative 34, in which the hydoxy group would be a connecting functionality with suitable DNA binding molecules.

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99 中性子捕捉療法による癌治療のためのホウ素キャリアーの設計と合成(ポスター発表の部)

根本尚夫, 蔡建平, 中村浩之, 岩本聡, 山本嘉則

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セッションID: 99
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_763

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Several new methods for the synthesis of boron-10 carriers have been developed for boron neutron capture therapy (BNCT). Two new methods for the synthesis of nucleosides having arylboronic moiety have been developed (Scheme 1 and 2). Chemistry of o-carborane has been studied since it is a nice candidate for BNCT in order to deliver sufficient quantity of boron atoms to tumor cells. The carbon-carbon bond formation reaction to o-carboranes proceeding under essentially neutral conditions has been accomplished for the first time (Scheme 3). o-Carboranes having a cascade type of polyglycerols 5 have been synthesized since o-carborane itself has strong lipophilic nature which causes a serious problem for the design of its derivatives (Scheme 4). The water solubility of 6 and 7 is 0.67M and 5.44M, respectively. Nucleoside derivatives having o-carborane moiety have been synthesized via palladium catalyzed coupling reaction and o-carborane formation reaction with decaborane-14 (Scheme 5). The biological activity of 11a, and 11b have been examined in vitro using B16 melanoma cells and TIG-I-20 Fibroblast cells. The boron atom is selectively concentrated in B16 Melanoma cells (model of a cancer cell), compared with in Hybroblast cells (model of a normal cell).

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100 高等植物において情報伝達に関与するGTP結合タンパク質(ポスター発表の部)

平田敏文, 泉俊輔, 岩田将和, 谷口博美, 谷口研至, 西森千晴

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セッションID: 100
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_770

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In connection with studies of the molecular mechanism of signal-transduction pathway in plant cells, occurrence of a GTP-binding protein (G protein) in the seedling of soybean (Glycine max) was investigated. Proteins from the seedling of soybean were subjected to SDS-PAGE and Western blot analysis with antibody raised against a GTP binding site of G protein in animal. The antibody was found to bound specifically to a 40 kDa protein (p40). [γ-^<35>S]GPT was incorpolated into p40 specifically. These results show that the G protein is present in seeding of soybean. On the other hand, incorporation of [5-^3H]mevalonic acid to the seedling resulted in formation of radioactive p40, which was hydrolyzed to give radioactive geranylgeraniol. This observation shows that p40 is modified by the C_<20>-prenyl chain.

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101 アブシジン酸(ABA)代謝酵素、ABA-oxygenaseの立体選択性(ポスター発表の部)

岡本昌彦, 中澤宏

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セッションID: 101
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_775

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Differences in catabolism of the enantiomers of abscisic acid (ABA) have been reported. Natural (+)-S-ABA is metabolized rapidly via two major pathways. One route involves the conjugation with glucose to form ABA glucose ester. A second pathway consists of oxidation of ABA by ABA oxygenase, the enzyme that forms 8'-hydroxyABA from ABA, to phaseic and dihydrophaseic acid (PA and DPA). The R-enantiomer metabolized slowly to the conjugates and 7'-hydroxy-(-)-R-ABA but not to PA or DPA. These results indicate that the stereoselectivity of ABA oxygenase is thought to be strict. However, no rigorous evidence has been obtained so far, because there were no analytical methods to establish the optical purity of PA and DPA. Recently we have achieved the direct optical resolution of PA and DPA by HPLC on the chiral stationary phase. To examine the stereoselectivity of ABA oxygenase, the PA and DPA isolated after feeding of (±)-RS-[^2H_6]-ABA to avocado mesocarp were analysed by the chiral HPLC methods. The peaks of unnatural PA and DPA arising from the unnatural enantiomer of ABA could be observed. These results show that the stereoselectivity of ABA oxygenase is not so strict under our experimental conditions.

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102 クワカルスにおけるDiels-Alder型付加化合物の一次代謝物からの生合成過程(ポスター発表の部)

羽野芳生, 鮎川昭男, 野村太郎, 上田伸一

原稿種別: 本文
セッションID: 102
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_780

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Biosynthesis of optically active Diels-Alder type adducts from primary metabolites in Morus alba callus cultures has been examined by the administration of ^<13>C_6-D-glucose and ^<13>C-labeled glycerols. Administration of ^<13>C_6-D-glucose to the M. alba callus cultures revealed that chalcomoracin (1) and kuwanon J (3) originates from two cinnamoylpolyketide + mevalonate units, respectively. In addition, the experiment indicated that the hydroxylation to the A and F rings of 1 corresponding to shikimate moiety takes place non-regioselectively after aromatization of the shikimate moiety. In an analogous experiment with [1,3-^<13>C_2]-glycerol, ^<13>C-labeled positions in the second and the third acetate units constructing the two isoprenyl units of 1 were opposite to those found in the starter acetate unit. The experiment with [2-^<13>C]-glycerol also gave the same result. The reversal way of the ^<13>C-labeling in the acetates constructing the mevalonate moiety has taken place presumably through the pentose phosphate cycle. In the M. alba callus cultures, the mevalonate has thus been biosynthesized from a glycolytically formed acetate as the starter acetate and the two successive acetates from the pentose phosphate cycle.

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103 Neoantimycinの生合成-立体化学的側面(ポスター発表の部)

武田美雄, 松本高志, 寺尾博充, 武智祐介, 新宮徹朗, Heinz G. Floss

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セッションID: 103
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_788

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The biosynthesis of 2,2-dimethy1-3,4-dihydroxy-5-phenylvaleric acid portion of neoantimycin (1), a metabolite of Streptoverticillium orinoci was examined. During the course of the assignments of ^1H- and ^<13>C-NMR signals of 1, the absolute stereochemistry at C-15 and C-16 were assigned as S and S. Feeding experiments of [^<13>C-Me]- methionine, [3-^<13>C]-sodium propionate and [2-^<13>C]-sodium acetate revealed that the C-10-C-13 portion was biosynthesized from propionate and methyl group of methionine and that methyl group of methionine and C-3 carbon of propionate were incorporated stereospecifically into C-12 and C-13, respectively. The chirality of the methyl group of methionine was found to be inversed when incorporated into C-12 as the results of the feeding experiment of [S-^1H, ^2H, ^3H-Me]-methionine followed by Kuhn-Roth oxidation and chiral analysis of resulting acetate. The intervention of phenylpyruvate was also demonstrated by feeding experiment of L-[U-^<14>C,2,3-H_2]-phenylalanine. The structure of a minor metabolite was elucidated as 2 based on its ^1H-COSY, ^1H-^<13>C-COSY and ^1H-^<13>C long range COSY spectra.

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原稿種別: 索引
p. 796-801
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_796

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p. App4-
発行日: 1992/09/10
公開日: 2017/08/18

DOIhttps://doi.org/10.24496/tennenyuki.34.0_App4

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