The Brazilian octocoral Phyllogorgia dilatata as a source of cytotoxic compounds

Abstract

The extensive marine biodiversity has proved to be a promising source of substances with biomedical potential. In this study, the cytotoxicity of the Brazilian octocoral Phyllogorgia dilatata (Gorgoniidae) was evaluated against two tumor cell lines and three bacterial strains. The methanol/dichloromethane crude extract presented no antibacterial activity up to the highest concentration tested (512 µg/mL), however it revealed a noteworthy antiproliferative effect against HCT-116 (80%) and MCF-7 (54%) cell lines at 50 μg/mL. Therefore, guided by the cytotoxic activity, a multistep chemical fractionation of the extract provided the subfraction 5 (PDPH2-5) with IC 50 values of 3.18 and 17.80 μg/mL against HCT-116 and MCF-7, respectively. The LC-HRMS/MS analysis of PDPH2-5 showed ions of m/z 219.1742 and 219.1743, characterized as (E,E) and (Z,E) germacrone, after a LC-DAD-SPE/NMR analysis of the hexanic fraction and comparisons of NMR data with the literature. Previously reported assessments to the cytotoxic activity of the (E,E)-diastereoisomer disclosed higher IC 50 values than that obtained for the PDPH2-5 fraction, suggesting, herein, a potentiated effect of the diastereoisomeric mixture. Such remark encourage further bioactivity studies with stereoisomer mixtures and reduce the urge for compound isolation.

NMR-Based Chromatography Readouts: Indispensable Tools to “Translate” Analytical Features into Molecular Structures

“…In an alternative approach, SPE trapped analytes can be transferred to conventional or low-volume NMR sample tubes. Again, the SPE serves as a purification step and the preparative workup of an extract to obtain the analyte of interest is avoided [145][146][147][148][149][150]. In summary, NMR spectroscopy can be used very successfully as a detector in highperformance liquid chromatography.…”

“…In an alternative approach, SPE trapped analytes can be transferred to conventional or low-volume NMR sample tubes. Again, the SPE serves as a purification step and the preparative workup of an extract to obtain the analyte of interest is avoided [ 145 , 146 , 147 , 148 , 149 , 150 ].…”