Aplysqualenols A and B: Squalene-Derived Polyethers with Antitumoral and Antiviral Activity from the Caribbean Sea Slug Aplysia dactylomela

The novel bromotriterpene polyethers aplysqualenol A (1) and B (2) have been isolated from the Caribbean sea slug Aplysia dactylomela, collected in Puerto Rico, and their structures and relative configurational assignments established from spectroscopic data aided by quantum mechanical calculations of NMR chemical shifts. Although both these compounds may be conceived as polyoxacyclic derivatives of the C30 squalene skeleton, it is notable that 1 and 2 each possess an unprecedented C15‐to‐C24 flexible chain of (14S*) spatial disposition that contains a unique ether bridge between C16 and C19. Biological activity screening tests revealed that, although aplysqualenol A (1) does not have significant antiinfective properties, it possesses potent antitumoral and antiviral activities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) Two novel triterpenoids, aplysqualenols A and B, have been isolated from Caribbean specimens of the anaspidean mollusk Aplysia dactylomela. The structures of 1 and 2, including their relative stereochemistries, were determined mainly by NMR spectroscopic techniques aided by quantum mechanical calculations of NMR properties (QM‐NMR).