Isolation of 24-homoscalarane sesterterpenoids from a sponge of the genus Lendenfeldia

The chemical screening of an algae-containing marine sponge identified as Lendenfeldia species has isolated two 24-homoscalarane sesterterpenoids, including a known compound, felixin A (1) and a new analogue, lendenfeldarane V (2). The structure of 1, obtained in a previous study, was cited for the first time in this study via single-crystal X-ray diffraction analysis. The structure of 2 was ascertained via 2D NMR experiments and a literature review. The absolute configurations of 1 and 2 were delineated with DP4+ computation and specific optical rotation. Homoscalarane 1 exhibited cytotoxicity towards MG63 human osteosarcoma cells.