58 沖縄産海綿Luffariella sp.より単離した新規セスタテルペンluffariolide A〜Eの構造(ポスター発表の部)

概要

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During our investigations on bioactive substances from Okinawan marine organisms, we have isolated five new cytotoxic sesterterpenes, named luffariolides A-E (1〜5), with known 6E and 6Z-neomanoalides (6 and 7) from Okinawan marine sponge Luffariella sp. The molecular formulae of 1〜5, C_<25>H_<36>O_3, C_<25>H_<38>O_4, C_<25>H_<40>O_3, C_<25>H_<38>O_4, and C_<25>H_<36>O_4, respectively, were established by HREIMS. The ^1H and ^<13>C NMR spectra of 1〜5 indicated sesterterpenes with cyclohexyl chromophore. The structures of 1〜5 were deduced by a combination of ^1H-^1H COSY, HOHAHA, and J-resolution experiments as well as comparison of physicochemical data of neomanoalides (6 and 7). The NOE experiments of 1 revealed 2Z, 4E and 6E geometries. The rerative stereostructures of 3, 4, and 5 were assigned as 3,4-trans by detailed analyses of ^1H-^1H coupling constants and NOE experiments The absolute stereostructures of 3, 4, and 5 were elucidated as 3Rand 4R by chemical degradations of 4R-luffariolide B (2). Luffariolides A-E (1〜5) exhibited cytotoxities against murine leukemia L1210 cells (IC_<50> 1.1〜7.8 μg/mL) in vitro.
天然有機化合物討論会の論文
1992-09-10