20 海綿由来真菌の新規細胞毒性代謝産物の化学構造とgymnastatin Iの全合成(口頭発表の部)

抄録

Marine microorganisms are potentially prolific sources of highly bioactive secondary metabolites that might represent useful leads in the development of new pharmaceutical agents. As part of our ongoing search for new antitumour metabolites produced by microorganisms from marine organisms, we have previously isolated gymnastatins A (1), B, C, D (2), E (3) - H (4) from a strain of Gymnascella dankaliensis originally separated from the marine animal Halichondria japonica, and their relative stereostructures have already been reported. Further investigation for metabolites of this fungal strain has now led to the isolation of nine additional new compounds, gymnastatins I(5)-M(9) and gymnasterones A(10)-D(13). The stereostructures of these metabolites have been elucidated by spectroscopic analyses. Furthermore, the absolute stereo-structures for compounds 1-4 were determined by spectroscopic analyses, some chemical transformations and X-ray structure analysis. The total syntheses of gymnastatins H (4) and I (5) were also achieved. Among the compounds tested this time, compounds 5 - 7 and 11 - 13 exhibited significant cytotoxicity against cultured P388 cells.