Antibacterial effect of the red sea soft coral Sarcophyton trocheliophorum

Abstract

The marine soft corals Sarcophyton trocheliophorum crude extracts possessed antimicrobial activity towards pathogenic bacterial strains, i.e. Bacillus cereus, Salmonella typhi, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Bioassay-guided fractionation indicated that the antimicrobial effect was due to the presence of terpenoid bioactive derivatives. Further biological assays of the n-hexane fractions were carried out using turbidity assay, inhibition zone assay and minimum inhibitory concentration for investigating the growth-inhibition effect towards the Gram-positive and Gram-negative bacteria. The fractions were screened and the structure of the isolated compound was justified by interpretation of the spectroscopic data, mainly mass spectrometry (GC-MS). The structure was assigned as (5S)-3-[(3E,5S)-5-hydroxy-3-hepten-6-yn-1-yl]-5-methyl-2(5H)-furanone and was effective at concentrations as low as 0.20 mg/mL. The above findings, in the course of our ongoing research on marine products, may implicate that the profound anti-microbial activity of the S. trocheliophorum soft corals, inhabiting the red sea reefs, is attributed to the presence of growth-inhibiting secondary metabolites mainly terpenoids.

Keywords:

• soft coral
• Sarcophyton trocheliophorum
• terpenoid
• in vitro
• antimicrobial assays

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The authors would like to express their utmost gratitude and appreciation to the University of Malaya [IPPP grant number PG069-2013A], [IPPP grant number PG068-2012B]; [Macrocyclic HIR grant number UM.C/625/1/HIR/151] for providing grant funding to conduct this study.