Angiotensin‐converting enzyme I inhibitory activity of phlorotannins from Ecklonia stolonifera
ABSTRACT As part of our study of the isolation of antihypertensive agents derived from natural marine products, the bioactivity of 10 edible Korean seaweeds were screened by angiotensin converting enzyme (ACE) inhibitory and peroxynitrite assays. Among the crude extracts of selected seaweeds, including five Phaeophyta (Ecklonia stolonifera, E. cava, Pelvetia siliquosa, Hizikia fusiforme, and Undaria pinnatifida), four Rhodophyta (Gigartina tenella, Gelidium amansii, Chondria crassicaulis, and Porphyra tenera) and one Chlorophyta (Capsosiphon fulvescens), the ethanol extracts of E. stolonifera, E. cava, P. siliquosa, U. pinnatifida, and G. tenella exhibited significant inhibitory properties against ACE at more than 50% inhibition at a concentration of 163.93 µg/mL. Phloroglucinol 1, eckstolonol 2, eckol 3, phlorofucofuroeckol A 4, and dieckol 5 had been isolated previously, and triphlorethol-A 6 and fucosterol 7 were isolated for the first time from E. stolonifera. Also, the ACE inhibitory and peroxynitrite scavenging properties of phlorotannins 1–6 were evaluated, along with fucosterol 7 obtained from E. stolonifera. Among profound peroxynitrite scavenging compounds 1–6, phlorotannins 3, 4 and 5 were also determined to manifest marked inhibitory activity against ACE, with 50% inhibition concentration (IC50) values of 70.82 ± 0.25, 12.74 ± 0.15, and 34.25 ± 3.56 µM, respectively.
- SourceAvailable from: Wendy A StirkFood Research International 11/2012; · 3.01 Impact Factor
- Food Research International 11/2012; · 3.01 Impact Factor
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ABSTRACT: In this study, fermentation broth of Eisenia bicyclis with Candia utilis YM-1 exhibited enhanced antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and food-borne pathogenic bacteria. To perform a more detailed investigation on the antibacterial activity, the fermented broth of E. bicyclis was extracted with methanol and further fractionated with organic solvents. After 1-day fermentation, the ethyl acetate (EtOAc)-soluble extract exhibited the highest anti-MRSA activity with minimum inhibitory concentration values ranging from 128 to 512 μg/mL, suggesting that the fermentation of E. bicyclis with C. utilis YM-1 may enhance antibacterial activity against MRSA. This effect was correlated to the result obtained by an increase in total phenolic contents in EtOAc-soluble extract. In addition, high-performance liquid chromatography analysis revealed that eckol, dieckol, dioxinodehydroeckol, and phlorofucofuroeckol-A contents in the EtOAc-soluble extract increased significantly. Thus, these results show that anti-MRSA activity of E. bicyclis fermented with C. utilis most likely originated from phlorotannins and allow the possible application of a variety of seaweed functional foods.Applied biochemistry and biotechnology 05/2013; · 1.94 Impact Factor