Structure of an anti-plasmin inhibitor, eckol, isolated from the brown alga Ecklonia kurome OKAMURA and inhibitory activities of its derivatives on plasma plasmin inhibitors.

Kodama, Masashi; Miura, Iwao; Kinzyo, Zyunei; Kido, Masaru; Mori, Hideo; Nakayama, Yasuo; Takahashi, Masayuki

doi:10.1248/cpb.37.349

Cited by 87 publications

(60 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…two AB systems at d 6.04 (1H, Jϭ2.7 Hz) and 5.82 (1H, Jϭ2.7 Hz), and d 6.01 (1H, Jϭ2.7 Hz) and 5.84 (1H, Jϭ2.7 Hz), and a singlet at 6.10 (1H) as well as five singlets indicating phenolic hydroxy protons at d 9.77, 9.64, 9.60, 9.27, and 9.26. These NMR spectral features are very similar to those of eckol (2) isolated from Eisenia bicyclis and Ecklonia kurome, 5,6) indicating that 1 is composed of three phloroglucinol units. The only difference between the 1 H-NMR spectra of 1 and 2 is that the former lacks the signals for one phenolic hydroxyl proton and one aromatic proton, suggesting that 1 has an additional aryl-ether linkage.…”

supporting

confidence: 55%

See 1 more Smart Citation

A New Phlorotannin from the Brown Alga Ecklonia stolonifera

Kang

Chung

Jung

et al. 2003

CHEMICAL & PHARMACEUTICAL BULLETIN

116

View full text Add to dashboard Cite

Ecklonia stolonifera OKAMURA is a member of the family of Laminariaceae, belonging to the order Laminariales as a perennial brown alga. The previous phytochemical investigations performed on this species resulted in the isolation of phloroglucinol, 1) phlorotannins 2) and ecklonialactones. 3,4) In the course of a continuous study on the active principles of this alga, we isolated a new phlorotannin with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, along with three known ones, of the methanolic extract of E. stolonifera. Column chromatography of the EtOAc soluble part from the methanolic extract of this alga yielded four phlorotannins, compounds 1-4 in the order of increasing polarity. The structures of 2, 3, and 4 were identified by comparison with published spectral data as eckol, phlorofucofuroeckol A, and dieckol, respectively (Fig. 1). [5][6][7][8] Compound 1 was obtained as off-white amorphous powder. The molecular formula of 1 was determined as C 18 . The carbon-13 nuclear magnetic resonance ( 13 C-NMR) spectrum of 1 indicated the presence of five non-substituted and thirteen O-bearing aromatic carbons, whereas the proton nuclear magnetic resonance ( 1 H-NMR) spectrum contained signals characteristic of five aromatic protons, i.e. two AB systems at d 6.04 (1H, Jϭ2.7 Hz) and 5.82 (1H, Jϭ2.7 Hz), and d 6.01 (1H, Jϭ2.7 Hz) and 5.84 (1H, Jϭ2.7 Hz), and a singlet at 6.10 (1H) as well as five singlets indicating phenolic hydroxy protons at d 9.77, 9.64, 9.60, 9.27, and 9.26. These NMR spectral features are very similar to those of eckol (2) isolated from Eisenia bicyclis and Ecklonia kurome, 5,6) indicating that 1 is composed of three phloroglucinol units. The only difference between the 1 H-NMR spectra of 1 and 2 is that the former lacks the signals for one phenolic hydroxyl proton and one aromatic proton, suggesting that 1 has an additional aryl-ether linkage. This was supported by the presence of a new oxygen-bearing carbon signal (d 122.7), which is characteristic of an aromatic carbon with two oxygenated neighbors, and also by the formation of a pentaacetate (1a) on usual acetylation. Analysis of HMQC, HMBC and NOESY spectra of 1 allowed an unambiguous assignment of all the proton and carbon signals (Table 1, Fig. 2). In the HMBC spectrum, each cross peak between d 9.77 and C-1 (d 146.1), C-2 (d 98.8), and C-14a , and C-10 (d 98.8) designated the existence of the hydroxyl groups at C-11 and C-9, respectively. Each cross peak between d 9.60 and C-5a (d 125.9), C-6 (d 140.1), and C-7 (d 97.6), established the presence of the hydroxyl group at C-6. The stereostructure of compound 1 was deduced to be planar and achiral by its specific rotation and a loss of additional anisotropic effect for the aromatic protons. It was found that specific rotation showed zero value and the similar chemical shifts not only between H-2 and H-10, but also between H-4 and H-12. Consequently, the structure of 1 was established as 5,8,13,14-tetraoxa-pentaphene-1,3,6,9,11-pentaol, named eckstolonol. Compounds 1-...

show abstract

supporting

confidence: 55%

“…1). [5][6][7][8] Compound 1 was obtained as off-white amorphous powder. The molecular formula of 1 was determined as C 18 .…”

mentioning

confidence: 99%

A New Phlorotannin from the Brown Alga Ecklonia stolonifera

Kang

Chung

Jung

et al. 2003

CHEMICAL & PHARMACEUTICAL BULLETIN

116

View full text Add to dashboard Cite

show abstract

“…Phlorotannins such as eckol and dieckol were firstly isolated from Ecklonia species, which are oligomeric polyphenol of phloroglucinol unit. 19,20) It has been reported that phlorotannins from Ecklonia species exhibit free radical scavenging activity, 20,21) anti-plasmin inhibiting activity, 19,22) anti-mutagenic activity, 23,24) bactericidal activity, 25) HIV-1 reverse transcriptase and protease inhibiting activity, 26) and tyrosinase inhibitory activity. 27) These facts imply that phlorotannins such as eckol and dieckol are responsible for these biological activities of Ecklonia species.…”

Section: Fig 1 Three Seaweed Extracts From Alariaceae Inhibit Tnfa-mentioning

confidence: 99%

The Inhibitory Effects of Eckol and Dieckol from Ecklonia stolonifera on the Expression of Matrix Metalloproteinase-1 in Human Dermal Fibroblasts

Joe

Kim²,

Choi

et al. 2006

Biological & Pharmaceutical Bulletin

139

View full text Add to dashboard Cite

The skin aging process can be considered to be due to intrinsic aging and photoaging. [1][2][3] The intrinsic aging is due to chronologic damage caused by slow and irreversible tissue degeneration whereas the photoaging is primarily the results of UV exposure.2,3) Clinically, chronologically aged skin is smooth, pale, and finely wrinkled. In contrast, photoaged skin is coarsely wrinkled and associated with dyspigmentation and telangiectasia. 1,4) Alterations of collagen, the major structural component of skin, in dermis layer have been suggested to be causes of the clinical changes observed in naturally aged and photoaged skin. 5,6) This collagen deficiency may arise from its reduced synthesis as well as increased degradation with a concomitant elevation of matrix metalloproteinase (MMP) expression. Ultraviolet irradiation induces the synthesis of MMP in human skin in vivo, and MMP-mediated collagen destruction accounts, in large part, for the connective tissue damage that occurs in photoaging. 7) Therefore, it is believed that the restoration of the collagen deficiency in aged human skin by the induction of new collagen synthesis and/or by the reduction of MMP will present a possible strategy for preventing and treating the clinical manifestations of skin aging, namely, wrinkles and skin laxity. MMPs can be divided into four categories based on the substrate preference: collagenases, gelatinases, stromelysins, and membrane-type MMPs. 8)Among human MMPs reported previously, MMP-1, which is an interstitial collagenase, is mainly responsible for the degradation of dermal collagen in human skin aging process. 9,10) Marine natural products provide a rich source of chemical diversity that can be used to design and develop new, potentially useful therapeutic agents. In this study, therefore, we tried to screen active compounds from 29 marine natural products which would be able to inhibit MMP-1 expression in human dermal fibroblasts and isolated eckol and dieckol from Ecklonia stolonifera which are major and active compounds to inhibit MMP-1 expression. MATERIALS AND METHODS Primary Human Dermal Fibroblast Cell Culture and Cytotoxicity TestPrimary human foreskin fibroblasts were established by outgrowth from biopsies of healthy donor of 10 years old, which was performed under the consent of volunteer, and cultured in Dulbecco's modified Eagle's media (DMEM) supplemented with 1% penicillin/streptomycin and 10% fetal bovine serum (FBS) in a humidified 5% CO 2 atmosphere at 37°C. Cultured cells at passages 4-10 were used for the experiments. For treatment, primary human dermal fibroblasts were maintained on culture media without FBS for 48 h. Cytotoxicity of cells was determined by the MTS assay (Promega, Madison, WI, U.S.A.) according to the manufacturer's instruction.Preparation of Seaweed Extracts Twenty nine different species of seaweed were harvested in the seashore in East Sea, Korea, and identified. The seaweeds were homogenized and crude components were extracted three times with methanol. The filtered supernatan...

show abstract

“…Recently, we reported that phloroglucinol provided cytoprotection against UVB-irradiated human HaCaT keratinocytes (13). Apart from their oxidative damage defense properties, seaweeds, particularly brown alga species, have been suggested to be involved in protective biological events such as bactericidal activity, radical scavenging activity, antimutagenic activity, and inhibition of anti-plasmin activity (14).…”

Section: Introductionmentioning

confidence: 99%

Phloroglucinol Exerts Protective Effects Against Oxidative Stress^|^ndash;Induced Cell Damage in SH-SY5Y Cells

et al. 2012

View full text Add to dashboard Cite

Abstract. In this study, we explored whether phloroglucinol (1,3,5-trihydroxybenzene) exerts protective effects against oxidative stress-induced cytotoxicity in SH-SY5Y cells, a neuroblastoma cell line. The central nervous system is especially vulnerable to oxidative stress because the brain consumes large amounts of energy to perform its complicated functions, but contains a lower level of anti-oxidant enzymes compared with other peripheral tissues. In SH-SY5Y cultures, pretreatment with 10 μg/ml of phloroglucinol attenuates the cytotoxicity of hydrogen peroxide. In addition, when assessed with 2′,7′-dichlorofluorescein diacetate dye, the increase in reactive oxygen species (ROS) induced by hydrogen peroxide was significantly reduced by pretreatment with phloroglucinol. ROS is known to cause lipid peroxidation of the cell membranes, the carbonylation of intracellular proteins, and DNA damage, which can lead to various cellular dysfunctions and eventually cellular death. We found that pretreatment with phloroglucinol down-regulated the levels of 8-isoprostane, protein carbonylation, and 8-hydroxy deoxyguanine caused by hydrogen peroxide treatment in SH-SY5Y cells. These results indicate that phloroglucinol exerts protective effects against oxidative stress-induced cell damage in SH-SY5Y cells.

show abstract

Structure of an anti-plasmin inhibitor, eckol, isolated from the brown alga Ecklonia kurome OKAMURA and inhibitory activities of its derivatives on plasma plasmin inhibitors.

Cited by 87 publications

References 1 publication

A New Phlorotannin from the Brown Alga Ecklonia stolonifera

A New Phlorotannin from the Brown Alga Ecklonia stolonifera

The Inhibitory Effects of Eckol and Dieckol from Ecklonia stolonifera on the Expression of Matrix Metalloproteinase-1 in Human Dermal Fibroblasts

Phloroglucinol Exerts Protective Effects Against Oxidative Stress^|^ndash;Induced Cell Damage in SH-SY5Y Cells

Contact Info

Product

Resources

About