Phytochemical, amino acid and fatty acid profile of selected brown and red seaweed species from Gulf of Mannar, Southeast India

An investigation was made on the proximate composition, amino acids, and fatty acids of the brown seaweeds; Padina gymnospora, Padina pavonica, Dictyota ciliolata, Sargassum wightii, and Sargassum ilicifolium, and red seaweeds; Gracilaria crassa, Gelidiella acerosa, Amphiroa fragilissima, Hypnea musciformis, and Halymenia venusta from the Mandapam region, Gulf of Mannar, Southeast India. Phytochemical analysis revealed totally 157 metabolites, among them, the solvent-extracts of the G. acerosa and S. wightii revealed maximum of phytochemical constituents. The analyses of seaweeds revealed the wide variations of carbohydrate (22.2–3.2%), protein (29.0–12.6%), and lipid (0.09–0.03%). And the highest values of carbohydrate, protein, and lipid were found in the S. wightii, D. ciliolata, and H. musciformis respectively. While the HPTLC analysis of the seaweeds revealed the presence of amino acids (essential: histidine, lysine, tyrosine, threonine, isoleucine, tryptophan, lysine, phenylalanine, leucine, valine, and taurine, and non-essential: alanine, asparagine, aspartic acid, glycine, cysteine, glutamic acid, glutamine, proline, arginine, and serine), the GC-MS analysis showed the presence of two saturated (palmitic acid and stearic acid) and four unsaturated (oleic acid, linolenic acid, alpha-linolenic acid, and morotic acid) - fatty acids. Further studies are required to evaluate the application of seaweeds in nutraceutical and pharmaceutical industries.