Structures of Polyacetoxybriaranes Extracted from the Sea Whip Octocoral Junceella fragilis

In the present study, an algae-containing octocoral, Junceella fragilis, was subjected to chemical screening. The analysis resulted in the extraction of six polyacetoxybriaranes: a new compound, identified as fragilide Z (1), alongside previously identified analogs, which included 12-epi-fragilide G (2), fragilide P (3), junceellolide D (4), junceellonoid A (5), and juncin ZI (6). The structures of compounds 2-6 were investigated through single-crystal X-ray diffraction analysis, whereas that of 1 was examined through two-dimensional nuclear magnetic resonance analysis. Compounds 1-6 proved active in enhancing the growth of MG-63 human mesenchymal stem cells.