Sesterterpenoids isolated from the marine sponge Coscinoderma bakusi

Area of Science:

• Marine Natural Products Chemistry
• Organic Chemistry
• Chemical Ecology

Background:

• Marine sponges are a rich source of structurally diverse secondary metabolites.
• Sesterterpenoids, a class of C20 terpenoids, exhibit a wide range of biological activities.
• The sponge Coscinoderma bakusi is a potential source for novel chemical entities.

Purpose of the Study:

• To isolate and characterize new sesterterpenoid derivatives from Coscinoderma bakusi.
• To investigate the chemical diversity of marine terpenoids.
• To evaluate the biological activities of isolated compounds.

Main Methods:

• Isolation and purification of compounds using chromatographic techniques.
• Structure elucidation using Nuclear Magnetic Resonance (NMR) spectroscopy and High-Resolution Mass Spectrometry (HRMS).
• Biological activity screening against hTRPA1, bacterial strains, cancer cell lines, and macrophages.

Main Results:

• Twelve neomanoalide derivatives (1-12) and two halisulfate derivatives (13-14) were isolated.
• Nine new compounds (4-9, 11, 12, 14) were identified, including coscilides A-H and halisulfate 11.
• Compound 7 showed activity against hTRPA1 (IC50, 34.5 μM) and Staphylococcus aureus (MIC, 32.0 μg/mL).
• Halisulfate derivative 14 inhibited NO production in LPS-activated RAW 246.7 macrophages (45% at 10.0 μM).

Conclusions:

• The study expands the known chemical diversity of marine sesterterpenoids.
• Compounds 11 and 12 possess rare terpenoid moieties.
• While most compounds showed low activity, the findings contribute to understanding marine natural product chemistry.