Two new eunicellin diterpenoids from the South China Sea gorgonian Muricella sibogae and their bioactivities

Abstract

A systematic re-study on gorgonian Muricella sibogae from South China Sea yielded 10 eunicellin-based diterpenoids including two new ones, sibogins C and D (1 and 2). Their structures were elucidated by extensive spectroscopic analyses (1D and 2D NMR, IR and MS) and by comparison with data reported in literatures. All the isolates were tested for cytotoxic and antifouling activities. Compounds 3 and 5 showed significant antifouling activity against the green mussel Perna viridis, and especially 3 was suggested as a potent low-toxic antifouling agent with a large LC₅₀/EC₅₀ value of 18.6. This was the first report on the antifouling activity of the eunicellin-type diterpenoids against the green mussel.

Keywords:

• gorgonian
• Muricella sibogae
• eunicellin-based diterpenoids
• cytotoxicity
• antifouling activity

Acknowledgements

Special thanks are given to Prof. Jing Li for the cytotoxicity tests and to Prof. Lin-Ren Zou for the specimen identification.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

^1. These authors contributed equally to this paper.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 41376142] and [grant number 41476107], and Hi-tech Research and Development Program of China [grant number 2013AA092902] and [grant number 2013AA093002].