Recently a great deal of interest has been developed towards natural bioactive components from seaweeds as functional food ingredients. Antioxidant, anti-inflammatory, antidiabetic and antihypertensive activities of ethyl acetate:methanol (EM) and chloroform solvent fractions (CHCl 3 ) of the brown seaweed Sargassum wightii were evaluated using different in vitro systems. The EM fraction registered greater Fe 2+ ion chelating ability (IC 50 0.52 mg/ml), and were effective in stabilizing the ABTS .+ (IC 50 0.82 mg/ml), and DPPH radicals (IC 50 0.32 mg/ml) than those derived from CHCl 3 fraction. The CHCl 3 fraction showed greater ACE-I inhibitory activity (IC 50 0.084 mg/ml), whilst the EM fraction exhibited greater anti-COX-1, 2, and 5-LOX (IC 50 0.03-0.05 mg/ml) and DPP-4 inhibitory (IC 50 ~ 0.013 mg/ml) properties. A significant colinearity was recorded between target bioactive properties and the electronegative groups Downloaded by [University of Sussex Library] at 04:46 24 June 2016 A c c e p t e d M a n u s c r i p t 2 2 appeared in the downfield space of the NMR spectra of the EM and CHCl 3 solvent fractions from S. wightii.

9Antioxidant potential of three brown seaweeds, Anthophycus longifolius, Sargassum 10 plagiophyllum, and Sargassum myriocystum obtained from Gulf of Mannar region of India were 11 evaluated utilizing different in vitro systems. EtOAc fraction of Anthophycus longifolius 12 registered significantly greater hydroxyl radical scavenging ability (IC 50 0.19 mg/mL) and were 13 effective in stabilizing the 2,2′-azino-bis-3-ethylbenzothiozoline-6-sulfonic acid (IC 50 1.23 14 mg/mL), and 1,1-diphenyl-2-picryl-hydrazil radicals (IC 50 0.48 mg/mL) (P < 0.05). No 15 significant differences in hydrogen peroxide scavenging and ferrous ion chelating properties of 16 the ethyl acetate extracts of the seaweeds were apparent. The utilities of reverse-phase high-17 performance liquid chromatography method hyphenated to diode-array detection for analyzing 18 the fingerprints of phenolic constituents in the solvent extracts and fractions of the seaweeds 19 were denoted. High-performance liquid chromatographic analysis indicated the presence of 20 phenolic acids in the solvent extracts of seaweeds. This study demonstrated the potential use of 21A. longifolius as candidate species to be used as a nutritional food supplement/functional foods to 22increase shelf life of food items for human consumption. 23 Journal of Aquatic Food Product TechnologyA c c e p t e d M a n u s c r i p t 2

Antidiabetic and anti-inflammatory potential of sulphated polygalactans isolated from the red seaweeds Kappaphycus alvarezii and Gracilaria opuntia were acquired by employing different in vitro systems. The sulphated galactopyran motif derived from G. opuntia possessed significant antidiabetic properties as identified by α-amylase (IC 50 0.04 mg/mL), α-glucosidase (IC 50 0.09 mg/mL) and dipeptidyl peptidase-4 (DPP-4, IC 50 0.09 mg/mL) inhibitory activities. Based on the detailed nuclear magnetic resonance spectroscopy experiments the sulphated galactopyran motif of G. opuntia was designated as →3)-4-O-sulfonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulfonato)-α-D-galactopyranosyl-(1→3)-4-O-sulfonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulfonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulfonato)-α-D-galactopyranan, while the one from K. alvarezii was demonstrated to be →4)-4-O-sulfonato-(2-Omethyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan. The sulphated galactans from G. opuntia showed greater antiinflammatory inhibitory activities as determined by cyclooxygenase-1 (COX-1, IC 50 0.01 mg/mL), cyclooxygenase-2 (COX-2, IC 50 0.03 mg/mL), and 5-lipoxygenase inhibitory activities (5-LOX, IC 50 0.24 mg/mL). This study revealed that the sulfated polygalactan enriched concentrate from G. opuntia can be used as potential therapeutic candidate to suppress the hyperglycemic response in diabetic conditions and inflammatory activity. They can be used to develop functional food ingredient in nutraceutical products.

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