Cytotoxic bromotyrosine derivatives from a two-sponge association of Jaspis sp. and Poecillastra sp.

Bioassay-guided chemical investigation of the lipophilic extract of a two-sponge association (Jaspis sp. and Poecillastra sp.) led to the isolation of two new bromotyrosine derivatives (1 and 2), along with known derivatives (3–12). Cyclobispsammaplin A (1) is a cyclic derivative of the previously reported bispsammaplin A (13), while psammaplin M (2) is composed of β-alanine (or aspartic acid) unit. Compounds 3, 4, 6, 10, and 12 are isolated for the first time from a sponge belonging to the subclass Tetractinomorpha. Structure elucidation was performed by a combination of high resolution mass and 2D NMR (principally COSY, HMBC, HSQC, and NOESY) spectroscopy. Compounds 1–4, 6, 10, and 12 were evaluated for cytotoxicity against a small panel of five human solid tumor cell lines and their activity was compared in relevance to their structure.