Cytotoxic Effects of Sarcophyton sp. Soft Corals—Is There a Correlation to Their NMR Fingerprints?
Pharmacognosy Department, College of Pharmacy, Cairo University, Kasr el Aini st., P.B. 11562 Cairo, Egypt
National Institute of Oceanography and Fisheries, Red Sea Branch, 84511 Hurghada, Egypt
Leibniz Centre for Tropical Marine Research, Fahrenheit Str.6, D-28359 Bremen, Germany
Department Bioorganic Chemistry, Leibniz Institute of Plant Biochemistry, Weinberg 3, D06120 Halle (Saale), Germany
Department of Medicinal Chemistry, Division of Pharmacognosy, Uppsala University, Box 574, SE-75 123 Uppsala, Sweden
Department of Chemistry, Faculty of Science, El-Menoufia University, 32512 Shebin El-Kom, Egypt
Authors to whom correspondence should be addressed.
Academic Editor: Vassilios Roussis
Mar. Drugs 2017, 15(7), 211; https://doi.org/10.3390/md15070211
Received: 30 May 2017 / Revised: 26 June 2017 / Accepted: 27 June 2017 / Published: 4 July 2017
Sarcophyton sp. soft corals are rich in cembranoid diterpenes, which represent the main chemical defense of corals against their natural predators in addition to their myriad biological effects in humans. Quantitative NMR (qNMR) was applied for assessing the diterpene variation in 16 soft coral specimens in the context of their genotype, origin, and growing habitat. qNMR revealed high diterpene levels in Sarcophyton sp. compared to Sinularia and Lobophyton, with (ent)sarcophines as major components (17–100 µg/mg) of the coral tissues. Multivariate data analysis was employed to classify samples based on the quantified level of diterpenes, and compared to the untargeted NMR approach. Results revealed that qNMR provided a stronger classification model of Sarcophyton sp. than untargeted NMR fingerprinting. Additionally, cytotoxicity of soft coral crude extracts was assessed against androgen-dependent prostate cancer cell lines (PC3) and androgen-independent colon cancer cell lines (HT-29), with IC50 values ranging from 10–60 µg/mL. No obvious correlation between the extracts’ IC50 values and their diterpene levels was found using either Spearman or Pearson correlations. This suggests that this type of bioactivity may not be easily predicted by NMR metabolomics in soft corals, or is not strongly correlated to measured diterpene levels.