Abstract
[Display omitted]
► The cytotoxic fraction of the cyanobacterium Moorea producens was investigated. ► This study reports the isolation of six compounds including the new malyngamides 4. ► The structures of the compounds were established by different spectroscopic analyses. ► The compounds were evaluated against cancer cell lines and M. tuberculosis.
In our continuing effort to discover new drug leads from Red Sea marine organisms, a sample of the marine cyanobacterium Moorea producens (previously Lyngbya majuscula) was investigated. Bioassay-directed purification of a tumor cell-growth inhibitory fraction of the organic extract of the Red Sea cyanobacterium afforded a new compound, malyngamide 4 (1), together with five previously reported compounds, malyngamide A (2) and B (3), (S)-7-methoxytetradec-4(E)-enoic acid (lyngbic acid, 4), aplysiatoxin (5) and debromoaplysiatoxin (6). Assignment of the planar structures of these compounds was based on extensive analysis of one- and two-dimensional NMR spectra and high-resolution mass spectrometric data. The isolated compounds were evaluated for their inhibitory activity against three cancer cell lines. In addition, the antibacterial activity of the compounds against Mycobacterium tuberculosis H37Rv ATCC 27294 (H37Rv) was evaluated. Lyngbic acid (4) was the most active against M. tuberculosis, while malyngamides 4 (1) and B (3) moderately inhibited the cancer cell lines. The other compounds were deemed inactive at the test concentrations.