• Journal of Marine Bioscience and Biotechnology
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• v.6 no.2
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• pp.76-83
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• 2014

Bacteria associated with marine sponges seemed to be concerned in halogenation/dehalogenation process of natural compounds. In the present study, the effect of hexabromobenzene (HBB) on the community structure of bacteria associated with a marine sponge Axinella sp. from Chuuk State under anaerobic condition was investigated. Regardless of 100 ppm HBB, most of detected microorganisms displayed high similarity with clones reported from coral or sponges. Amongst, Desulfovibrio marinisediminis like clones were dominant. Clones affiliated with Lentisphaerae and Fusibacter paucivorans (Clostridia) were detected at the conditions without HBB but clones affiliated with Vallitalea guaymasensis (Clostridia) increased its proportion with HBB. From these results and previous reports clones affiliated with D. marinisediminis and V. guaymasensis seemed to be concerned in halogenation/dehalogenation process.

• ALGAE
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• v.31 no.3
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• pp.277-287
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• 2016

Five fractions separated from Nannochloropsis oculata using solvent-solvent partition chromatography of 80% methanolic extract of N. oculata (NOM) followed by the open silica column chromatography of its hexane fraction (NOMH) for the anti-inflammatory on RAW 264.7 cells and anti-cancer activities on HL-60, A-549, HEP-3B, HCT-116, and SW-480 cancer cells. All the five fractions showed potential anti-inflammatory activities against lipopolysaccharide-stimulated RAW 264.7 macrophages cells with IC₅₀ values less than 6.25 μg mL⁻¹. Moreover, 90% n-hexane column elution of NOMH (NOMH90) down-regulated lipopolysaccharide-stimulated protein levels of inducible nitric oxide synthase and cyclooxygenase-2. Furthermore, NOMH90 showed marked cytotoxic effect on the HL-60 cells with IC₅₀ value of 23.58 ± 0.09 μg mL⁻¹. In addition, Hoechst 33342 cell permeable dye used to visualize the apoptosis nucleus and cell cycle analysis measured Sub-G1 DNA contents to confirm reduction of the cell viability in NOMH90 treated cells due to induction of apoptosis in HL60. These results are quite related to the phytosterol contents of the NOMH fractions and the results suggest N. oculata extracts might be useful as potential sources of natural anti-inflammatory and anti-cancer compounds. In conclusion, the sterol content in N. oculata might provide a promising role in future medicines in anti-inflammatory and anti-cancer.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1226-1232
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• 2004

Extracts from seventeen seaweeds were determined for tyrosinase inhibitory activity using mushroom tyrosinase with L-tyrosine as a substrate. Only one of them, Ecklonia stolonifera OKAMURA (Laminariaceae) belonging to brown algae, showed high tyrosinase inhibitory activity. Bioassay-guided fractionation of the active ethyl acetate (EtOAc) soluble fraction from the methanolic extract of E. stolonifera, led us to the isolation of phloroglucinol derivatives [phloroglucinol (1), eckstolonol (2), eckol (3), phlorofucofuroeckol A (4), and dieckol (5)]. Compounds 1~5 were found to inhibit the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$ values of 92.8, 126, 33.2, 177, and 2.16 ${\mu}g$ /mL, respectively. It was compared with those of kojic acid and arbutin, well-known tyrosinase inhibitors, with $IC_{50}$ values of 6.32 and 112 ${\mu}g$ / mL, respectively. The inhibitory kinetics analyzed from Lineweaver-Burk plots, showed compounds 1 and 2 to be competitive inhibitors with $K_i$ of $2.3{\times}10^{-4}\;and\;3.1{times}10^{-4}$ M, and compounds 3~5 to be noncompetitive inhibitors with $K_i$ of $1.9{\times}10^{-5},\;1.4{\times}10^{-3}\;and\;1.5{\times}10^{-5}$ M, respectively. This work showed that phloroglucinol derivatives, natural compounds found in brown algae, could be involved in the control of pigmentation in plants and other organisms through inhibition of tyrosinase activity using L-tyrosine as a substrate.

• Natural Product Sciences
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• v.21 no.4
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• pp.278-281
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• 2015

Chemical investigation on a colonial marine tunicate, Didemnum sp. led to the isolation of a series of indole alkaloids including a new (1) and two known metabolites (2-3). Based on the spectroscopic analysis including 1D and 2D NMR along with MS spectra, the structure of 1 (16-epi-18-acetyl herdmanine D) was elucidated as a new amino acid derivative. The absolute configuration of 1 was determined by comparison of specific rotation with the known compound. The structures of compounds 2 and 3 were also identified as bromoindole containing compounds N-(6-bromo-1H-indole-3-carbonyl)-L-arginine and (6-bromo-^1H-indol-3-yl) oxoacetamide, respectively, based on $^1H$ and $^{13}C$ NMR data, MS data and specific rotation value. Their pharmacological potentials as antibacterial agents and FXR antagonists were investigated, but no significant activity was found. However, the structural similarity of compound 1 to compound 4 suggested the anti-inflammatory potential of compound 1.

• Journal of the Korean Chemical Society
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• v.47 no.1
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• pp.43-46
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• 2003

From Portulaca oleracea which is widely distributed in Korea and has long been used as a folk medicine, two biophenolic glycosides, 3-hydroxy-1-(2-hydroxyethyl)phenyl-4-O-${\beta}$-D-glucopyranoside (1) and 2-(3,4-dihydroxyphenyl) ethyl-O-${\beta}$-D-glucopyranoside (2) were isolated using column chromatography and reversed-phase HPLC. $^{13}C$ NMR spectral assignment for these compounds was revised by the extensive 2-D NMR experiments such as NOESY, HMQC, and HMBC. These compounds showed a considerable antioxidant effect in DPPH assay system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.6
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• pp.909-915
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• 1997

The nitrite scavenging effect of methanol extracts of marine algae were evaluated to discover new natural nitrite scavengers. Among the tested seaweeds, Ecklonia stolonifera, an edible brown algae, showed the strongest scavenging effect. The MeOH extract was then sequentially partitioned into $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, EtOAc, n-BuOH, and $H_2O$ layers. The EtOAc and n-BuOH fraction demonstrated high levels of nitrite-scavenging activity while the $CH_2Cl_2,\;CH_2Cl_2$ insoluble interface, and $H_2O$ fractions were inactive. A column chromatography of the EtOAc fraction through silica gel and Sephadex LH-20 yielded phloroglucinol and a new compound tentatively named phlorotannin A. The nitrite scavenging activity of phloroglucinol $(IC_{50}=3.9{\mu}g/ml)$ was more potent than that of L-ascorbic acid $(IC_{50}=65.0{\mu}g/ml)$. However, phlorotannin A $(IC_{50}=193.2{\mu}g/ml)$ showed only low levels of activity. From the above results, it is possible to suggest that both the MeOH extract and their fractions and isolated phloroglucinol and phlorotannin A obtained from E. stolonifera may be applicable as scavengers of nitrite, which is a precursor for the formation of carcinogenic N-nitroso compounds.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.3
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• pp.212-216
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• 2004

Peroxynitrite formation in vivo is implicated in numerous human diseases and there is considerable interest in the use of antioxidants and natural products for their treatment. The three components (1-3) isolated from Sargassum thunbergii as well as the organic solvent-soluble fractions and the aqueous layer of S. thunbergii were evaluated for their potential to scavenge authentic ONOO$\^$-/ and ONOO$\^$-/ derived from 3-morpholinosydnonimine (SIN-1). The antioxidant activity of the individual fractions was in the order of 85% aqueous (aq.) MeOH＞n$\^$-/ BuOH＞n-hexane＞H$_2$O. The three known compounds, sargahydroquinoic acid (1), sargaquinoic acid (2) and sargachromenol (3) showed peroxynitrite-scavenging activities comparable to those of L-ascorbic acid and penicillamine. These results showed a possible antioxidant activity in major constituents of S. thunbergii.

• Journal of Environmental Science International
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• v.20 no.7
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• pp.845-855
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• 2011

The aim of this paper is to correlate the release characteristics of marine and lake sediment with their vicinal oxic conditions. We performed lab-scale simulation experiments using field sediment and water in order to compare the release concentrations and the release rates one another. To provide a few different kinds of oxic environments we used natural air flow and some oxygen releasing compounds such as $CaO_2$ and $MgO_2$. In case of phosphates, in each oxic condition, removal of phosphorus via biological activity and that via salt precipitation with the metal ions lowered the release rates. The behavior of the nitrogen-origin salts seemed to greatly depend on the typical biological actions - growth of biomass, nitrification, and partial denitrification. Generally speaking, the control of releases of $NH_3$-N, $PO_4$-P, T-N and T-P was successful under the oxic conditions meanwhile COD, nitrates and nitrites were difficult to reduce the releases into the bulk water because of the considerable microbial oxidation. Based on typical diffusive mass transfer kinetics the changes of concentrations of the nutrients were computed for qualitative and quantitative comparisons.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3473-3477
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• 2015

Plants and their by-products offer a diverse mixture of chemical constituents like natural antioxidants. Date-pits are rich in phenolic compounds that have antioxidant potential. The main objective of this study was to investigate the protective effect of a date-pit extract (DPE) against AOM-induced colonic carcinogenicity and oxidative stress. Thirty-two weanling male Sprauge-Dawley rats were randomly divided into four groups (eight rats in each group). All rats were fed basic diet and water ad libitum, and randomly distributed per treatment groups as follows: negative controls injected with normal saline once a week for two weeks, a cancer group injected intra-peritoneally with azoxymethane (15mg/kg body weight) for two consecutive weeks, and DPE treated groups receiving the extract via the oral route (1.5ml/day) for the entire experiment in the presence or absence of AOM injection. Results showed that DPE contained phytonutrients that were capable of inhibiting chemically-induced oxidative stress in the rat colonic cells. In those animals that consumed DPE, a protective effect was observed against AOM-induced oxidative stress in rat colonic cells as evident by a significant decrease in MDA and oxidized DCF formation in AOM injected and DPE fed groups. It is concluded that DPE has potential antioxidant and anticarcinogenic properties.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1386-1392
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• 2010

A bacterial strain designated GR5$^T$, previously isolated from a freshwater culture pond in Taiwan while screening for bacteria for antimicrobial compounds, was characterized using a polyphasic taxonomic approach. Strain GR5$^T$ was found to be Gram-negative, aerobic, greenish-yellow colored, rod-shaped, and motile by means of a single polar flagellum. Growth occurred at $10-40^{\circ}C$ (optimum, $35^{\circ}C$), pH 7.0-8.0 (optimum pH 8.0), and with 0-2.0% NaCl (optimum, 0.5-1.0%). The major fatty acids were $C_{16:1}{\omega}7c$(36.3%), $C_{16:0}$(16.6%), $C_{12:0}$ 3-OH (12.5%), and $C_{18:1}{\omega}7c$(9.1%). The major respiratory quinone was Q-8, and the DNA G+C content of the genomic DNA was 51.9 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain GR5$^T$ belongs to the genus Rheinheimera, where its most closely related neighbors are Rheinheimera texasensis A62-14B$^T$ and Rheinheimera tangshanensis JA3-B52$^T$ with sequence similarities of 98.1% and 97.5%, respectively, and the sequence similarities to any other recognized species within Gammaproteobacteria are less than 96.5%. The mean level of DNA-DNA relatedness between strain GR5$^T$ and R. texasensis A62-14B$^T$, the strain most closely related to the isolate, was $26.5{\pm}7.6%$. Therefore, based on the phylogenetic and phenotypic data, strain GR5$^T$ should be classified as a novel species, for which the name Rheinheimera aquatica sp. nov. is proposed. The type strain is GR5$^T$ (=BCRC 80081$^T$=LMG 25379$^T$).