title: Characterization of substituted aryl meroterpenoids from red seaweed Hypnea musciformis as potential antioxidants.
abstract: The ethyl acetate fraction of red seaweed Hypnea musciformis was purified to yield three substituted aryl meroterpenoids, namely, 2-(tetrahydro-5-(4-hydroxyphenyl)-4-pentylfuran-3-yl)-ethyl-4-hydroxybenzoate (1), 2-2-[(4-hydroxybenzoyl)-oxy]-ethyl-4-methoxy-4-2-[(4-methylpentyl)oxy]-3,4-dihydro-2H-6-pyranylbutanoic acid (2) and 3-((5-butyl-3-methyl-5,6-dihydro-2H-pyran-2-yl)-methyl)-4-methoxy-4-oxobutyl benzoate (3). The structures of these compounds, as well as their relative stereochemistries, were confirmed by exhaustive NMR spectroscopic data analyses. Compound 1 exhibited similar 2,2'-diphenylpicrylhydrazyl radical inhibiting and Fe(2+) ion chelating activities (IC50 25.05 and 350.7μM, respectively) as that of commercial antioxidant gallic acid (IC50 32.3 and 646.6μM, respectively), followed by 3 (IC50 231.2 and 667.9μM, respectively), and 2 (IC50 322.4 and 5115.3μM, respectively), in descending order of activities. Structure-activity relationship analysis revealed that the antioxidant activities of these compounds were directly proportional to the steric and hydrophobic parameters. The seaweed derived aryl meroterpenoids might serve as potential lead antioxidative molecules for use in pharmaceutical and food industries.
authors.affiliation: Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India. Electronic address: kajal_cmfri@yahoo.com.
authors.forename: Kajal
authors.initials: K
authors.lastname: Chakraborty
authors.affiliation: Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.
authors.forename: Deepu
authors.initials: D
authors.lastname: Joseph
authors.affiliation: Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.
authors.forename: Minju
authors.initials: M
authors.lastname: Joy
authors.affiliation: Marine Biotechnology Division, Central Marine Fisheries Research Institute, Ernakulam North, P.B. No. 1603, Cochin, India.
authors.forename: Vamshi Krishna
authors.initials: VK
authors.lastname: Raola
mesh_terms: D000085:Acetates / Q000737:chemistry; D000975:Antioxidants / Q000737:chemistry*; D001688:Biological Products / Q000737:chemistry*; D005707:Gallic Acid / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000032:analysis / Q000737:chemistry*
chemical_list: D000085:Acetates; D000975:Antioxidants; D001688:Biological Products; D010936:Plant Extracts; D013729:Terpenes; D005707:Gallic Acid; C007650:ethyl acetate
keywords: Antioxidant activity; Aryl meroterpenoids; Hypnea musciformis; Nuclear magnetic resonance spectroscopy; Seaweed; Structure-activity relationship