Bioactivity-guided fractionation of Ecklonia stolonifera was used to determine the chemical identity of bioactive constituents, with potent antioxidant activities. The structures of the phlorotannins were determined on the basis of spectroscopic analysis, including NMR and mass spectrometry analysis. The antioxidant activities of the isolated compounds were evaluated by free radical scavenging activities in both in vitro and cellular systems. The anti-inflammatory effects of the isolated compounds were evaluated by determining their inhibitory effects on the production of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in lipopolysaccharide (LPS)-induced RAW 264.7 murine macrophage cells. The results indicated that phlorofucofuroeckol A, dieckol, and dioxinodehydroeckol showed potential radical scavenging activities against 2,2-diphenyl-1-picrylhydrazyl. Among them, phlorofucofuroeckol A and dieckol significantly suppressed the intracellular reactive oxygen species level assayed by 2',7'-dichlorofluorescein diacetate assay in LPS-induced RAW 264.7 cells. Phlorofucofuroeckol A significantly inhibited the LPS-induced production of NO and PGE(2) through the down-regulation of inducible nitric oxide synthase and cyclooxygenase 2 protein expressions. In conclusion, these results suggest that phlorofucofuroeckol A has a potential for functional foods with antioxidant and anti-inflammatory activities.

The effects of solvent-to-bran ratio (2:1 and 3:1, w/w), extraction temperature (40 and 60~ and time (5, 10, 15, 20, and 30 rain) were studied for hexane and isopropanol extraction. Increasing the solvent-to-bran ratios and extraction temperature increased the amounts of crude oil, vitamin E and oryzanol recovered for both solvents. An extraction time of 15 min was sufficient for optimum crude oil, vitamin E, and oryzanol extraction. Preheated isopropanol (3:1 solvent/bran ratio and 60~ extracted less crude oil (P < .05) but more vitamin E (P < .05) and similar amounts of oryzanol (P > .05) relative to preheated hexane. The data suggest that isopropanol is a promising alternative solvent to hexane for extraction of oil from stabilized rice bran.

Rice bran was extruded at 110, 120, 130, and 140ЊC with post extrusion holding times of 0, 3, and 6 min and stored at ambient temperatures for 1 yr. Holding time had no effect (pϾ0.05) on hydrolytic stability whereas 110ЊC was slightly less effective in maintaining hydrolytic stability. Increased holding times reduced (pϽ0.05) total vitamin E content. Oryzanol concentration was lower (pϽ0.05) only after 6 min holding time. Oryzanol was relatively more stable to extrusion temperatures than vitamin E. The highest retentions of total vitamin E and oryzanol were found in raw rice bran during storage. Increased extrusion temperatures reduced the retention of vitamin E and oryzanol during storage.

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