Changes of extracted bioactive compounds from brown algae (Cystoseira indica) after conversion to mill and tablet using a quantitative metabolomics approach

There is developing importance in the biomedical use of seaweeds such as brown algae, mostly due to their contents of bioactive substances. In the present study, bioactive compounds in hydroalcoholic extract of brown algae (Cystoseira indica) was profiled and investigated in three forms of extract, mill, and tablet. A portion of the extracted solution was kept as the control, and the residue was converted to mill and tablet. The metabolic profiles of the treatments were determined by the use of 1H NMR spectroscopy. Entire identified metabolites were effective in cluster separation in all treatments in principal component analysis (PCA) loadings plot. Based on the PCA score plot, the mill treatment was closer to the extracted solution in PC2 compared to the tablet treatment. Eight metabolites in the extracted solution were eliminated in the mill and the tablet treatments. In ANOVA analysis (p ˂ 0.05), there were not any significant differences in acetamide, N-acetylglucosamine, and ribose between mill and tablet treatments. Allantoin and pyridoxine were significantly different between mill and extract, and they were missed in tablet treatment. Sarcosine, riboflavin, pyruvate, N-acetylcysteine, and 2-hydroxyisobutyrate were present and significantly different in all three treatments. N-Acetylglycine was significantly different in the extract and the tablet treatment, but it was not observed in mill. ANOVA analysis results confirmed the results obtained by PCA analysis suggesting that mill treatment was more effective in metabolite preservation compared to tablet treatment, which can be used as the commercialized form.