Chemical characterization of the brown seaweed <i>Cystoseira compressa</i> collected from the Algerian coast: a promising source for biostimulant metabolites

This study aimed to investigate the chemical composition of the brown seaweed <i>Cystoseira compressa</i> collected from the Algerian coast, focusing on phytohormone, amino acid, and sugar -profiles. LC-MS/MS analysis of the amino acid profile revealed high levels of L-alanine (23.10 mg/100g extract), L-glutamic acid (19.75 mg/100g extract), and L-aspartic acid (14.53 mg/100g extract), HPLC analysis identified key phytohormones, with zeatin (243.96 mg/100g extract) being the most abundant. Significant quantities of essential sugars, including arabinose (4002 mg/100g extract) and sucrose (3667 mg/100g extract), were also detected. The findings of this research deepen our understanding of key metabolites in <i>Cystoseira compressa</i> that support plant growth and nutrition and suggest a significant potential for developing seaweed-based biostimulants, emphasising the value of using marine resources to improve agricultural practices.