• Journal of the Korean Wood Science and Technology
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• v.31 no.3
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• pp.11-16
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• 2003

On nitrobenzene oxidation of aspen, spruce, and knauf wood meals gave rise to vanilline, syrigaldehyde, p-hydroxybenzoaldehyde, vanillic acid, and other minor oxidation products. The phenolic aldehydes (p-hydroxybenzaldehyde, vanilline, and syringaldehyde) are derived from oxidative degradation of the corresponding 4-hydroxyphenylpropane units and their ethers. The lignin content of knauf wood meals was different as the concentration of NaOH solution and cooking temperature. The lignin contents of aspen, spruce, and knauf wood meals were decreased as laccase treatment. The laccase caused C-oxidation, demethylation, cleavage in phenolic groups and C-C cleavage in syrigyl structures.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.33 no.1
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• pp.73-79
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• 2001

Stricter environmental demands have increased the need to replace conventional C/D bleaching sequence by chlorine-free sequence. Permanganate is well known as a powerful oxidant and have been used industrially in variable fields. However, it has considered to be difficult to use permanganate as a bleaching reagent because of its strong oxidative effect decreasing the viscosity of pulps extremely. We have tried to use permanganate as a bleaching reagent for KP under the mild condition and it was clear that pernanganate oxidized lignin remained in pulps selectively and increased pulp brightness decreasing K number of pulps with small degradation of cellulose. We have employed the neutral condition in the permanganate bleaching process in this study. In this case, permanganate was converted to manganese dioxide after bleaching reaction. The manganese dioxide is remained in the treated pulp fibers because of its insolublity in water. So it was required to reduction the manganese oxide to manganese ion by using reductants with acid. In this paper, we proposed to use oxalic acid as a reducing reagent converting manganese oxide to manganese ion after bleaching reaction. Oxalic acid plays the role as a reductant and a acid, so post-treatment after bleaching became to be easy by using oxalic acid. On the study using lignin model compounds, it was clear that permaganate react with phenols firstly, after that oxalic acid reduce the manganese oxide to manganese ion in the mixture of permanganate, phenols and oxalic acid. Several lignin model compounds ($\textit{p}$-hydroxybenzaldehyde, vanillin, syringaldehyde, veratraldehyde) are selected to elucidate the effect of substituents on reaction rate and its mechanism with permanganate including oxalic acid in this study. Except for veratraldehyde, the rate of oxidative degradation of phenolic compounds by permanganate with oxalic acid are higher than neutral condition. Especially, the degradation rate of $\textit{p}$-hydroxybenzaldehyde are strongly dependent on pH of reaction mixture. On the other hand, the degradation rate of veratraldehyde are decreased with decreasing pH and main degradation product is veratric acid. This result indicate that pH of bleaching liquor should be kept over 2 to degrade of non-phenolic lignin in the pulps effectively in permanganate bleaching.

• Culinary science and hospitality research
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• v.20 no.5
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• pp.29-33
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• 2014

In this study, we examined the antioxidant activity of the naturaceutical extract in vitro using total phenolic contents, total flavonoids contents, DPPH radical scavenging activity, reducing power assay, and phenolic acid contents. The total phenolic and total flavonoids contents of naturaceutical extract were 5.46 mg/g, 2.21 mg/g, respectively. The DPPH radical scavenging activity of natraceutical extract varied from 18.77 ($200{\mu}g/mL$) to 3.44 ($1,000{\mu}g/mL$). The reducing power of the natraceutical extract absorbance varied from 1.07 (0.78 mg/mL) to 3.44 (12.5 mg/mL), and reducing power of extract presented a concentration-dependent activity increase. The highest amounts of trans-ferulic acid, p-hydroxybenzoic acid, p-coumaric acid, vanillin, vanillic acid, p-hydroxybenzaldehyde, and trans-cinnamic acid were observed in the naturaceutical extract at the levels of 750.79, 619.75, 531.34, 222.04, 219.28, 107.40, and $89.56{\mu}g/g$, respectively. The results imply that this antioxidant effect of the naturaceuticals extract could be harnessed in the management and prevention of degenerative diseases associated with oxidative stress.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.134.1-134
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• 2003

The purpose of this study was to investigate the release of p-hydroxybenzoic acid and other compounds from cell wall materials(CWM) and their cellulose fraction from carrot with chemical and enzymatic hydrolysis. To investigate this effect on cell wall chemistry of carrot, alcohol insoluble residue(AIR) of CWM were prepared and were extracted sequentially with water, imidazole, CDTA(-1, -2), Na$_2$CO$_3$(-1, -2), KOH(0.5, 1.0 and 4M), to leave a residue. These were analysed for their carbohydrate and phenolic acids composition. Arabinose and galactose were the main noncellulosic sugars. Phenolics esterified to cell walls in carrot were found to consist primarily of p-hydroxybenzoic acid with minor contribution from vanillin, ferulic acid and p-hydroxybenzaldehyde. p-Hydroxybenzoic acid was quite strongly bound to the cell wall. The contents of p-hydroxybenzoic acid in 0.5M KOH, Na$_2$CO$_3$-2, IM KOH, and ${\alpha}$-cellulose were 2,097, 1,360, 1,140, and 717 $\mu\textrm{g}$/g AIR from CWM, respectively. Alkali labile unknown aromatic compound(C$\sub$7/H$\sub$10/O$_2$) was found in ${\alpha}$ -cellulose hydrolyzate digested with driselase and cellulase. This compound was also found in hydrolyzate of 2 M trifluoroacetic acid at 120$^{\circ}C$ for 2 hours. Driselase treatment solubilized only 46.6 $\mu\textrm{g}$/g of the p-hydroxybenzoic acid from carrot AIR. These results indicate that p-hydroxybenzoic acid was associated with neutral polysaccharides, long chain galactose and branched arabinan from graded alcohol precipitation.

• Natural Product Sciences
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• v.22 no.2
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• pp.140-145
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• 2016

Seven phenolic compounds including p-coumaric acid (1), 4-hydroxybenzoic acid (2), 4-hydroxybenzaldehyde (3), vanillic acid (4), luteolin (5), acacetin (6), and tricin (7), were isolated from the methylene chloride and ethyl acetate fractions of Echinochloa utilis grains. Compounds (1 - 4, 6) were isolated for the first time from this plant. These compounds were tested for inhibitory activities against LPS-induced NO production in RAW 264.7 cells. Compounds 5 and 6 displayed significant inhibitory effects, with $IC_{50}$ values of $27.9{\pm}2.6$ and $14.0{\pm}1.1{\mu}M$, respectively. The results suggested that E. utilis ethanolic extract may be used as a potential source of anti-inflammatory agents and functional foods for the treatment of allergic diseases.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.766-770
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• 2009

Hot water extracts of Camellia japonica flower buds were found to have the higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the other solvent extracts. Five phenolic compounds were isolated and purified from the ethyl acetate soluble-neutral fraction of hot water extracts by Sephadex LH-20 column chromatography and octadecyl silane-high performance liquid chromatography using the guided assay of DPPH radical scavenging. Based on mass spectrometer and nuclear magnetic resonance, the isolated compounds were identified as p-hydroxybenzaldehyde (1), vanillin (2), dehydroxysynapyl alcohol (3), 7S,7'S,8R,8'R-icariol $A_2$ (4), and (-)-epicatechin (5). Four compounds (1-4) except for 5 were newly identified in this plant. Their DPPH radical scavenging activities as 50% scavenging concentration decreased in order to 5 $(20\;{\mu}M)>{\alpha}-tocopherol$ $(29\;{\mu}M)>4$ $(67\;{\mu}M)>3$ $(72\;{\mu}M)>1=2$ ($>250\;{\mu}M$). These results indicate that the antioxidant effect of the hot water extract of C. japonica flower buds may partially due to 5 isolated phenolic compounds.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.266-271
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• 2007

Bisphenol A (BPA) has been widely used as a monomer for production of epoxy resins and polycarbonate plastics. The annual production of BPA exceeds 640,000 metric tons in worldwide. BPA, a suspected phenolic endocrine disrupter, is moderately soluble and frequently detected in industrial wastewater. To date, HPLC and GC has been used for BPA analysis. However, HPLC and GC-analysis need high operation lost, experts, and an elaborate pre-treatment of samples, and is difficult to apply on-time and mass analysis. Therefore, simple, mass and rapid detection of BPA in environments is necessary. In the present study, spectrophotometric method of BPA quantification was developed. Based on blue-color product formation with BPA and ferric chloride/ferricyanide under the optimized conditions, the standard curve was acquired $({\lambda}_{750}=0.061\;BPA\;[{\mu}M]+0.07155,\;R^2=0.992)$. Using an established method, the BPA contents in the soil extract, and different water samples and living products, including disposable syringe, cup and plastic tube, were analyzed. The results suggested that the method is useful for BPA determination from different massive samples. Since the BPA metabolites, nontoxic 4-hydroxyacetophenone or 4-hydroxybenzaldehyde, did not form blue-color product, this method is also useful to screen a microorganism for BPA bioremediation.