Asteriscane-type sesquiterpenoids from the soft coral Sinularia capillosa

Area of Science:

• Marine Natural Products Chemistry
• Organic Chemistry
• Chemical Ecology

Background:

• Soft corals are a rich source of diverse secondary metabolites.
• Asteriscane-type sesquiterpenoids are rare and have not been previously reported in soft corals.
• Marine organisms are increasingly investigated for bioactive compounds.

Purpose of the Study:

• To isolate and characterize new chemical constituents from the soft coral Sinularia capillosa.
• To investigate the potential biological activities of the isolated compounds.

Main Methods:

• Chemical examination using extensive spectroscopic analyses (NMR, MS, etc.).
• Determination of absolute configurations via CD and ECD calculations, Mosher's method, and chemical conversion.
• Bioactivity screening, including antifouling assays and in vitro anti-inflammatory assays.

Main Results:

• Isolation of 14 new asteriscane-type sesquiterpenoids (capillosananes A-N) and four new seco-asteriscanes (capillosananes O-R).
• Identification of (-)-sinularone A and sinularone A.
• Capillosananes Q and R represent novel seco-asteriscane skeletons.
• Capillosanane A demonstrated potent antifouling activity (IC₅₀ = 9.70 μM).
• Capillosananes B, I, and (-)-sinularone A inhibited tumor necrosis factor-alpha (TNF-α).

Conclusions:

• This study reports the first isolation of asteriscane-type sesquiterpenoids from soft corals.
• The identified compounds possess unique chemical structures and exhibit promising biological activities.
• These findings contribute to the understanding of soft coral chemical diversity and potential pharmaceutical applications.