Antifouling activity of terpenoids from the corals Sinularia flexibilis and Muricella sp. against the bryozoan Bugula neritina

Abstract

Marine natural products are promising sources of green antifoulants. Here, a new compound (1) was isolated from the soft coral Sinularia flexibilis. This compound, another nine cembranoids (2–10) from S. flexibilis, and three eunicellin-type diterpenoids (11–13) from the gorgonian Muricella sp. were tested for antifouling activity against larval settlement of the bryozoan Bugula neritina. Compounds 2, 3, 4, 9, 12, and 13 exhibited significant antifouling activity, with EC₅₀ values of 18.2, 99.7, 67.9, 35.6, 33.9, and 49.3 μM, respectively. Analysis of the structure-activity relationships suggested that the hydroxy group at C-13 in compound 4 reduced its antifouling activity.

Graphical Abstract

Keywords:

• Antifouling terpenoids
• Sinularia flexibilis
• Muricella sp.
• Bugula neritina
• structure-activity relationship (SAR)

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was funded by the National Key Research and Development Program of China under Grant 2018YFC1407505, the Science and Technology Development Fund of Tianjin Education Commission for Higher Education under Grant 2019ZD031, the Youth Innovation Fund Project of Xiamen under Grant 3502Z20206053, and the Project of the Key Laboratory of Marine Ecological Monitoring and Restoration Technology, Ministry of Nature Resources under Grant 2020ZX01.