Molecular mechanism of chemical self-defense of the protozoan ciliates.

在纤毛虫间捕食-被捕食相互作用的持续研究中，我们报道了从一种异毛纤毛虫中分离并鉴定了一种防御毒素。在对纤毛虫Dileptus margaritifer作为捕食者和另一种异毛纤毛虫Sprostomum teres作为捕食者的捕食-被捕食相互作用的初步研究中，我们观察到S.teres对捕食者的逃避行为以及在细胞膜正下方的S.teres中皮质小泡的存在，这表明S.teres对捕食者有一定的毒性物质。本文报道了一种从细菌中分离出的有毒物质螺环素的分离和结构测定。通过过滤和浓缩溶剂去除细胞后，残留物在乙酸乙酯和水中分配。在有机层中，基于对纤毛虫尾部草履虫…的致死毒性的活性部分用1.5%Me0H/CH_2C_(？)lt；12&gt；(Rf值为0.44)洗脱的硅胶层析得到更多的组分。该部位含有一个新的化合物螺孔蛋白(1)，其分子式经HREIMS和^1H及^1H和^&lt；13&gt；C核磁共振确定为C_&lt；16&gt；H_&lt；14&gt；O_5。根据~1H，~(13)&t；~(13)C核磁共振和紫外光谱，确定了螺孔蛋白的结构为spiro[(2，5-dimethy1-5，6，7，8-tetrahydronaphtalene-1，4-dione)-8，6‘-(吡喃-2’，5‘-二酮)，这是一种具有未知碳骨架的螺环化合物。螺孔菌素A和螺孔菌素B的全合成建立了螺孔菌素的相对立体化学结构，并通过圆二色谱和密度泛函理论对螺孔菌素的绝对化学进行了估算。通过分析HMQC、HMBC和用[1-13C]、[2-13C]和[1，2-^&lt；13&gt；C2]醋酸钠加料实验得到的富13C样品的HMQC、HMBC和~(13)C谱，确定了眼睑红素C的核磁共振信号。较少

In the continuing study on predator-prey interaction between ciliates, we reported the isolation and structural determination of a defense toxin climacostol from a heterotrich ciliate Climacostomum virens. On the preliminary study of the predator-prey interaction between ciliates Dileptus margaritifer as a predator and Spirostomum teres an another heterotrich ciliate as a prey, we observed elusive behavior of S.teres from the predator and the presence of the cortical vesicle in S.teres just beneath the cell membrane, which suggested that S.teres had some toxic substance against the predator. We report the isolation and structural determination of a toxic substance spirortomin from S.teres.The whole cells of S.teres were dipped in aqueous 70% EtOH. After removal of the cells by filtration and concentration of the solvent, the residue was partitioned between ethyl acetate and water. From the organic layer, an active fraction based on lethal toxicity against a ciliate Paramecium caudatum … More was obtained by chromatography on silica gel eluted with 1.5% Me0H/CH_2C_<12> (Rf value 0.44). The fraction contained a new compound spirostomin (1), whose molecular formula was estimated to be C_<16>H_<14>O_5 by HREIMS and ^1H and ^<13>C NMR. Based on ^1H, ^<13>C NMR and UV spectra, the structure of spirostomin was established as spiro[(2,5-dimethy1-5,6,7,8-tetrahydronaphtalene-1,4-dione)-8,6'- (pyrane-2',5'-dione)], a spiro compound having a carbon framework hitherto unknown. The relative stereochemistry of spirostomin was established by the total synthesis of spirostomine A and B. The absolute chemistry of spirostomine was also estimated by the CD spectra and the result based on the DFT calculation.Blepharismins, toxic pigments of the ciliate Blepharisma japonicum, are polycyclic ring-condensed compounds. Assignment of ^<13>C NMR signals for blepharismin C, a major constituent of blepharismins, was achieved by analyses of the HMQC, HMBC, and INADEQUATE spectra of 13C-enriched samples obtained by feeding experiments using sodium [1-13C], [2-13C], and [1,2-^<13>C2]acetates. Less