Preliminary phytochemical screening for various secondary metabolites, quantitative and qualitative analysis of Yemeni brown seaweed Sargassum vulgare

Sargassum Vulgare was collected from the Red sea coastlines, Al-Hodeida, Yemen, and dried. The dried powder was subjected to consecutive extraction by methanol. The dried methanol extract was subjected to solvent fractionation (n-hexane-chloroform-ethyl acetate and n-butanol solvents). Sargassum vulgare polysaccharides (S.R1P, S.R1M, S.R5s, and S.R5ss) were isolated by precipitation with methanol. [19] The methanol extract and n-hexane fraction were evaluated phytochemically. The physicochemical characteristics and FT-IR analysis of Sargassum vulgare polysaccharides (S.R1P, S.R1M, S.R5s, and S.R5ss) were investigated, the chemical composition of the Sargassum vulgare n-hexane fraction was evaluated by Gas Chromatography-Mass Spectrometry (GC-MS) analysis [8]. Phytochemical investigation revealed that both methanol extract and n-hexane fraction of Sargassum vulgare contained alkaloids, phytosterols, terpenoids, fats, and fixed oils. Moreover, Sargassum vulgare methanol extract exhibited a high amount of carbohydrates (41.33%) mainly polysaccharides [40][41][42]. The physicochemical characteristics and FT-IR analysis of polysaccharides (S.R1P, S.R1M, S.R5s, and S.R5ss) revealed that all the obtained polysaccharides were alginates with traces of sulfate polysaccharides except S.R1M. [30][34][35]