Suberitolactams A-D and Suberitopyridines A-B: New γ-lactam and Pyridine Alkaloids Isolated from the South China Sea Sponge Pseudospongosorites suberitoides.

Four new γ-lactam alkaloids, suberitolactams A-D (1-4), two new pyridine alkaloids, suberitopyridines A-B (7-8), and two known compounds (5-6) were isolated from the South China Sea sponge Pseudospongosorites suberitoides. The structures were elucidated by detailed 1D and 2D NMR experiments along with HRESIMS analysis and single crystal X-ray diffraction. Compounds 1 and 8 showed moderate to weak antiviral activity against H1 N1 virus with IC values of 27.6 and 13.3 μM, respectively.