Two New Bromophenols from the Red AlgaOdonthalia corymbifera

Abstract

Two novel bromophenols (1 and 2) were isolated from an extract of a red alga, Odonthalia corymbifera, together with a known bromophenol (3). The novel bromophenols were determined as 4-bromo-2, 3-dihydroxy-6-hydroxymethylphenyl 2, 5-dibromo-6-hydroxy-3-hydroxymethylphenyl ether (1) and bis(2, 3-dibromo-4,5-dihydroxybenzyl) ether (2), from spectroscopic evidence. Compounds 1-3 were found to be inactivators of alpha-glucosidase.

Antidiabetic properties of polysaccharide- and polyphenolic-enriched fractions from the brown seaweedAscophyllum nodosumThis article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products.

“…Initial chemical characterization of the polyphenolics using NMR suggests that phlorotannins structures of high molecular mass are responsible for the a-glucosidase inhibitory activity (results not shown). In addition, structural analysis did not uncover the presence of any brominated compounds so the polyphenols are distinct from the a-glucosidase-inhibiting bromophenols of red seaweed reported by (Kurihara et al 1999).…”

“…Inhibition of a-glucosidase by acarbose (Precose) or miglitol (Glycet) delays the absorption of glucose from the small intestine (Bischoff 1994;Lebovitz 1997) and, as demonstrated in the STOP-NIDDM trial (Chiasson et al 2002), is an effective antidiabetic therapeutic approach. Research has also revealed that a variety of food materials contain compounds that inhibit a-glucosidase including fermented soybean (Fujita et al 2001), purple sweet potato (Matsui et al 2001), propolis (Matsui et al 2004), leaf tea (Youn et al 2004), fish protein hydrolysates (Matsui et al 1999) and seaweed (Kurihara et al 1999). Extracts prepared from these sources effectively blunt the appearance of glucose in blood after carbohydrate tolerance testing in animals and, in the case of fermented soybean extract, in a humans (Fujita et al 2001).…”

Protective effect of Neorhodomela aculeata methanolic extract through the suppressive action on NF-κB and STAT pathway in IL-1β and IFN-γ induced β-cell damage

“…Previous chemical studies on some species of this family have more than thirty monoaryl and diaryl bromophenols (Zhao et al, 2004), which exhibit antibacterial, antioxidant, a-glucosidase inhibitory, and anti-inflammatory activities. N. aculeata have also several bromophenols (Phillips and Carlyle, 1981;Xu et al, 2003) and the chemicals exhited α-glucosidase inhibitors used in oral anti-diabetic drugs for diabetes mellitus type 2 (Kurihara et al, 1999;Lim et al, 2006;Xu et al, 2003). Thus, in the extract of N. aculeata, the potential candidate chemical showing cytoprotective effects on pancreatic βcells seem to be a kind of phenols such as bromophenols but further studies are needed to determine which components of N. aculeata mediate cyoprotective effects in pancreatic β cells.…”

“…The red alga, Neorhodomela aculeata (Perestenko) Masuda has been used by the Chinese for centuries for the treatment of certain illnesses (Li et al, 1994). The methanolic extract of N. aculeata and a number of bromophenol metabolites isolated from their methanolic extract have antibacterial, antioxidant, and anti-inflammatory activities (Kurihara et al, 1999;Lim et al, 2006). However, no pharmacological properties of N. aculeata have been reported as antioxidant and anti-inflammatory agents in the pancreas.…”

Antioxidant and Anti-inflammatory Activities of the Methanolic Extract of Neorhodomela aculeate in Hippocampal and Microglial Cells

“…19) The methanolic extract of N. aculeata and a number of bromophenol metabolites isolated from their methanolic extract have antibacterial activities. 20) However, no pharmacological properties of N. aculeata have been reported as antioxidant and anti-inflammatory agents in the brain. Therefore, these experiments were conducted to evaluate the properties of the methanolic extract of N. aculeata with neuronal cells and microglial cells.…”