Cytotoxic neviotane triterpene-type from the red sea sponge Siphonochalina siphonella

BACKGROUND: Siphonochalina siphonella is a marine sponge collected from saudi Red Sea water and scare study from this region. OBJECTIVE: To isolate the anticancer triterpenes with potent cytotoxicity from marine sponge, Siphonochalina siphonella and state the mode of action in cancer cell lines. MATERIALS AND METHODS: The sponge material was collected, extracted with organic solvent, and fractionated on different adsorbents. The structure of the pure metabolites were elucidated employing different spectroscopic techniques including 1D ((1)H and (13)C) and 2D (COSY, HMQC and HMBC) NMR, and MS spectroscopy. RESULTS: A new Neviotine-C (1) was obtained, along with four known metabolites (2-5). All compounds, except 5, were tested towards MCF-7, PC-3 and A549 and showed effects with IC(50) in range 7.9-87 μM, whilst, 3 showed potent anti-proliferative activity against PC-3 and A549 with IC(50) = 7.9 ± 0.120 and 8.9 ± 0.010 μM, respectively. CONCLUSION: Compounds (1-4) showed significant cytotoxic activities, while 3 showed potent effect. The antiproliferative of 3 was attributed to significant S-phase cell cycle arrest.