• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.11-16
• /
• 2005

Humic substances(HS) from raw and process waters at a conventional water treatment plant were isolated and extracted by physicochemical fractionation methods to investigate their characteristics. They are characterized for their functionality, chemical composition, and spectroscopic characteristics using FT-IR(Fourier transform infrared) and $^1H-NMR$(proton nuclear magnetic resonance) spectroscopy. Humic fraction gradually decreased from 47.2% to 26.4%(from 0.97 to 0.54 mgC/L) through conventional water treatment processes. Concentration of phenolic groups in the HS fraction gradually decreased from 60.5% to 21.8%(from 12.2 to $6.0\;{\mu}M/L$ as phenolic-OH) through water treatment. In the case of carboxylic groups, the concentration increased from 39.5% to 46.9%(from 7.9 to $10.6\;{\mu}M/L$ as COOH) by pre-chlorination, but gradually decreased to 34.2%($9.4\;{\mu}M/L$ as COOH) through sedimentation and sand filtration. From the results of the FT-IR and $^1H-NMR$ spectra of HS, the content of carboxylic groups increased and ratio of aliphatic protons to aromatic protons($P_{Al}/P_{Ar}$) also increased through water treatment, which indicated the increase of aliphatic compounds.

• Korean Journal of Food Science and Technology
• /
• v.28 no.6
• /
• pp.1157-1163
• /
• 1996

Bangah, one of the herbs grown in Korea, was investigated for its antioxidant activity. The ether extracts of bangah herb was separated into neutral, phenolic, acidic and basic fractions and further separated into subfractions. Antioxidative activities were measured by hydrogen donating activity (HDA), peroxide value (POV), thiobarbituric acid (TBA) value and inhibition activity against lipid peroxidation of rat liver microsomes, The subfraction components were identified by GC/MS and NMR. Phenolic, though being very small in quantity, showed higher antioxidant activity at all assay system by hydrogen donating activity. POV, TBA value and inhibition activity against lipid peroxidation of rat liver microsomes. Five subfractions(P-1, P-2, P-3, P-4 and P-5) were fractionated from phenolic fraction of bangah herbs, and subfraction P-2 among them showed strong antioxidant activity on a level with BHT or gallic acid at each assay system. Four compounds (peak I, peak II, peak III and peak IV) were isolated by gas chromatogram of TMS derivatives of subfraction P-2 and thes compounds were confirmed to be phenolic substance having -OH and COOH group. There subfractions (N-1, N-2 and N-3) were fractionated from neutral fraction of bangah herbs, and subfraction N-2 among them showed highest antioxidant activity and inhibition activity against lipid peroxidation of rat liver microsomes. Subfraction N-2 was indentified to be estragole by H-NMR spectroscopy.

• Food Science and Preservation
• /
• v.15 no.3
• /
• pp.456-460
• /
• 2008

Santalum album has been used as a folk medicine for treatment of skin diseases, inflammation, gonorrhea, gleet, and cystitis in India and other Asian countries. In a search for possible bioactive agents from natural sources, we found that the various solvent extracts of S. album showed significant antioxidative effect in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity test and moderate other biological functions submitted to the several bioassay systems for whitening and cytotoxicity evaluations. Among the tested extracts displayed DPPH radical scavenging activity, and the 70% acetone extract showed the most potent activity with an $IC_{50}$ value of $18.6\;{\mu}g/ml$, more potent than a positive control, L-ascorbic acid ($IC_{50}$, $28.7\;{\mu}g/mL$). Also, anti-lipid peroxidation, tyrosinase inhibitory, and cytotoxic effects were determined in each experiment. Total phenolic content of 70% acetone extract was found to be 117.1 mg equivalent of gallic acid per g of extract. Previous phytochemical investigation reveals the presence of phenolic compounds. The results indicate that S. album possess potential antioxidant activity and phenolic constituents are responsible for this capacity.

• Journal of Adhesion and Interface
• /
• v.2 no.3
• /
• pp.16-24
• /
• 2001

The curing behavior of a phenolic resin (F/p: 1.3, 1.9, 2.5 for resol resin, F/P: 0.5, 0.7, 0.9 for novolac resin) has been studied by FT-IR spectroscopy. In this study is to synthesis of resol and novolac type phenolic resin with different F/P molar ratios and to compare the level of cure at different curing temperature conditions ($130^{\circ}C$, $160^{\circ}C$, $180^{\circ}C$ for resol resin, $160^{\circ}C$, $170^{\circ}C$, $180^{\circ}C$ for novolac resin) for 3, 5, 7, 10, 20, and 60 (min.), respectively. The conversion (${\alpha}$) was determined by the ratio of the peak area with time to the peak area of non-baked phenolic QH ($3300cm^{-1}$) at spectra. It is concluded that the initial curing rate of resol and novolac resin was increased as the molar ratio of formaldehyde/phenol increased and as the curing temperature of resin increased. According to the analysis was by the homogenous first-order model, the initial curing rate of resol and novolac resin was increased as the molar ratio of formaIdehyde/phenol increased at specific curing temperature.

• KSBB Journal
• /
• v.10 no.2
• /
• pp.183-190
• /
• 1995

The effects of enzymatic pretreatments on the bleaching of kraft pulp were studied. The kappa number of pulp samples which represents the lignin content of pulp decreased by 25.2% by the pretreatments with xylanase(EC 3.2.1.8, Pulpzyme HB) while it decreased by 13.7% without enzyme pretreatments after the extraction of the pretreated pulp samples in 1N NaOH. To enhance the effects of enzymatic pretreatment on the bleaching of kraft pulp, phenols were used as radical carriers with the simultaneous use of peroxidase(EC 1.11.1.7, Novozyme 502), $H_2O_2$, and xylanase. Guaiacol (1mM) was most effective by decreasing the kappa number by 29.6% when a low initial concentration of $H_2O_2$ (0.1mM) was used. The use of either a higher initial concentration of $H_2O_2$ or phenols lacking electron donating substituents such as phenol and p-chloyophenol, however, decreased the efficiency of enzymatic pretreatment indicating that the production rate and the stability of phenolic radicals are important parameters.

• Food Science and Biotechnology
• /
• v.18 no.1
• /
• pp.124-129
• /
• 2009

Antioxidant activities of the extract of red seaweed, Polysiphonia morrowii, were evaluated using several in vitro assay systems. Activity-guided fractionation revealed that the 90% MeOH fraction of the P. morrowii extract exhibited the highest antioxidant activity, and that this fraction had a high total phenolic content ($135.7{\pm}5.0\;mg$ gallic acid/g extract). Therefore, the antioxidant activities of the 90% MeOH fraction against 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, reducing power, ferrous chelating, and hydrogen peroxide were investigated. The results revealed that the antioxidant activities of the 90% MeOH fraction were similar and/or superior to that of commercial antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). In addition, the ability of the 90% MeOH fraction to inhibit oxidative damage to DNA was assessed by measuring the conversion of the supercoiled pBR322 plasmid DNA to the open circular form. The 90% MeOH fraction was found to significantly protect this hydroxyl radical-induced DNA damage in a dose-dependent manner. Taken together, these findings suggest that the 90% MeOH fraction of P. morrowii extract and/or its constituents has the potential for use as a new bioresource of antioxidants.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.1
• /
• pp.13-18
• /
• 2006

The antioxidant activity of the extract of Erigeron annuus was assessed by means of two different in vitro tests: bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test) and the scavenging of authentic peroxynitrite in company with peroxynitrite generation from 3-morpholinosydnonimine (SIN-1). In both tests, the 85% aq. MeOH and n-BuOH soluble fractions of the crude extract showed a significant scavenging effect on peroxynitrite and DPPH radical in comparison to L-ascorbic acid. And bioassay-guided fractionation of the n-BuOH soluble fraction led to the isolation of three compounds: Apigenin (1), quercetin-3-O-glucoside (2), and caffeic acid (3). The structures of the isolated compounds were elucidated on the basis of their spectroscopic data and their antioxidant activities were measured by determining their capacity to scavenge peroxynitrite and the DPPH radical.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.8
• /
• pp.1161-1164
• /
• 2004

Calculations are presented for phenol ?acetonitrile - $(water)_n$ (n = 1-3) clusters. We examine the nature of interactions in the mixed clusters by calculating and comparing the structures, relative energies and harmonic frequencies of isomers with different type of hydrogen bonding. The conformers exhibit quite different patterns in the shifts of the CN and OH stretching frequencies, depending on the type of hydrogen bonding. Cyclic hydrogen bonding among the water molecule(s), acetonitrile and phenolic OH proves very important in determining the relative stability. It is also shown that acetonitrile tends to bind to the OH group of phenol in low energy conformers.

• Nutrition Research and Practice
• /
• v.2 no.4
• /
• pp.247-251
• /
• 2008

This study investigated the antioxidant activity of methanol (MeOH) and water extracts from roots of Cirsium japonicum in vitro, MeOH extract showed a stronger tree radical scavenging activity than water extract. However, both of extracts showed a concentration dependent hydroxyl radical scavenging activity, reducing power and metal chelating ability, MeOH extract had greater phenolic and flavonoid contents than water extract. The antidiabetic activity of these two extracts was evaluated by the a-glucosidase inhibition assay, The water extract showed a considerable a-glucosidase inhibitory activity. To our knowledge, this may be the first time to report the antioxidant and antidiabetic activities in Cirsium japonicum roots.

• Natural Product Sciences
• /
• v.24 no.4
• /
• pp.241-246
• /
• 2018

The herbs of Lamium takesimense Nakai (Lamiaceae) is used to treat spasmodic and inflammatory disease. The four polar compounds, ecdysterone, isoacteoside, rutin and lamiuside C, were isolated and identified from the BuOH fraction of the L. takesimense MeOH extract. HPLC quantification was performed on a Capcell Pak C18 column ($5{\mu}m$, $4.6mm{\times}250mm$) with a gradient elution of $H_2O$ and 0.05% acetic acid in MeOH. The HPLC method was validated in terms of linearity, sensitivity, stability, precision, and accuracy. The quantitative level in plant material was determined as the following order: lamiuside C (4, 3.75 mg/g dry weight) > ecdysterone (1, 1.93 mg/g) > isoacteoside (2, 1.32 mg/g) > rutin (3, 0.97 mg/g).