Metachromins U–W: Cytotoxic Merosesquiterpenoids from an Australian Specimen of the Sponge Thorecta reticulata

• DOI: 10.1021/np200041v
• Publication Date: 2011-04-22T14:16:26Z
• Authors: Simon P. B. Ovenden; Jonathan L. Nielson; Catherine H. Liptrot; Richard H. Willis; Dianne M. Tapiolas; Anthony D. Wright; Cherie A. Motti
• Keywords: Molecular Structure; Antineoplastic Agents; Marine Biology; 01 natural sciences; Porifera; 0104 chemical sciences; Animals; Humans; Drug Screening Assays, Antitumor; HT29 Cells; Nuclear Magnetic Resonance, Biomolecular; Sesquiterpenes

Three new merosesquiterpenoids, metachromins U, V, and W (1-3), were isolated from a specimen of the marine sponge Thorecta reticulata collected off Hunter Island, Tasmania, Australia. Structures of the new compounds were elucidated through extensive NMR investigations and comparison with literature values. The cytotoxicities of 1-3 were assessed against a panel of human tumor cell lines (SF-268, H460, MCF-7, and HT-29) and a mammalian cell line (CHO-K1). All compounds were found to have 50% growth inhibition activities in the range 2.1-130 μM, with 2 being the most active (GI50 2.1-10 μM).