Bioassay-guided fractionation approach led to identification of two novel compounds; (4-(hydroxymethyl)-3-methoxy-1H-pyrazol (1) and mycalene (2), alongside with four known metabolites; octadecane (3), hexatriacontane (4), 1-heneicosanol (5) and heptatriacontanoic acid (6) from the Red Sea marine sponge Hemimycale sp. The ethyl acetate fraction showed a noticeable cytotoxic activity against the lung cancer cell line (A549) with IC₅₀ value of 75.54 µg/ mL. Structural elucidation was achieved using a combination of 1D and 2D nuclear magnetic resonance (NMR) spectroscopy and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS). To elucidate the potential mechanism of action behind the cytotoxic effects against lung cancer, a multi-faceted approach combining in silico network pharmacology, experimental validation, and molecular docking studies were employed. Both compounds …