Tuberculosis (TB) is a dreadful infectious disease and a leading cause of mortality and morbidity worldwide, second in 2020 only to severe acute respiratory syndrome 2 (SARS-Cov-2). With limited therapeutic options available and a rise in multidrug-resistant tuberculosis cases, it is critical to develop antibiotic drugs that display novel mechanisms of action. Bioactivity-guided fractionation employing an Alamar blue assay for <i>Mycobacterium tuberculosis</i> strain H37Rv led to the isolation of duryne (<b>13</b>) from a marine sponge <i>Petrosia</i> sp. sampled in the Solomon Islands. Additionally, five new strongylophorine meroditerpene analogues (<b>1</b>-<b>5</b>) along with six known strongylophorines (<b>6</b>-<b>12</b>) were isolated from the bioactive fraction and characterized using MS and NMR spectroscopy, although only <b>13</b> exhibited antitubercular activity.