• Korean Journal of Weed Science
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• v.8 no.3
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• pp.283-290
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• 1988

This study was conducted to clarify the identification of phytotoxic compounds from 5 upland weeds which had been collected at their maturity age in the field of Kyungpook province, Korea. 5 weed species including Stellaria aquatica strongly inhibited the lettuce seed germination. These 5 species were Amaranthus lividus, Stellaria aquatica, Achyranthes japonica, Polygonum perfoliata and Galinsoga ciliata. the degree of inhibitory effects according to various solvent extracts such as ethanol, aceton, chloroform and ether was different as species. In total phenol and diphenol content G. ciliata had largest amount of total phenol with 2.75mg/g, P. perfoliata 1.8mg/g, S. aquatica 1.7mg/g, A. lividus 1.28mg/g, A. japonica 1.27mg/g respectively. A. lividus had much amount of p-cresol, hydroquinone, ferulic, caffeic, p-cl-benzoic and p-coumaric in order. S. aquatica, A. japonica, P. perfoliata and G. ciliata had a large quantity of ferulic, caffeic, 7-OH-coumarin and protocatechuic acids in common. The amount of fatty acids was existed 8.49mg/g in S. aquatica, 7.14mg/g in A. japonica, 7.10mg/g in G. ciliata, 5.49mg/g in P. perfoliata and 4.2mg/g in A. lividus respectively. Most of 4 weeds except G. ciliata had much oxalic acid to the extent of 14-22mg/g. however it appeared that G. ciliata had much quantity of feruic and citric acids.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.273-279
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• 2005

The degradation of o-chlorophenol(o-CP) in the presence of NaOH and the byproducts formed were investigated in a supercritical water(SCW) destruction process. The conversion of o-CP in the absence of NaOH was less than 20%, however it showed 100% conversion in the presence of NaOH(mole ratio[NaOH]/[o-CP] over than 2) with a residence time of less than 1 second. The formation of PAHs and the phenolic compounds formed were decreased in the presence of NaOH. The results revealed that the formation of byproducts during the destruction of o-CP in SCW was effected by the addition of NaOH. Phenol, cresols, chlorinated phenols, PAHs, p,p'-dihydroxybiphenyl and oxygenated polyaromatic compounds such as 1-indanone, dibenzofuran and dibenzo-p-dioxin were detected in both conditions(presence and absence of NaOH). At the same time, in the presence of NaOH, 2-ethylphenol, o-hydroxyacetophenone, hydroquinone, 4-allylphenol, 3-phenoxyphenol and 4,4'-oxybisphenol were also detected. The observed results suggest that the destruction of o-CP in SCW with NaOH occurs through a number of complicated reaction pathways. Dibenzofuran and dibenzo-p-dioxin were also detected during destruction of o-CP by SCW. The above observation suggests that there may be a common relationship between the thermal incineration process and SCW decomposition process.

• Natural Product Sciences
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• v.7 no.2
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• pp.38-44
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• 2001

NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.

• Archives of Pharmacal Research
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• v.22 no.4
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• pp.335-339
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• 1999

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cylcic voltammetry. The voltammograms obtained could be classified ito 4 patterns (patterns 1-4). Patterns 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration ($IC_{50}$) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as patterns 4, showed the highest inhibitory activity (lowest $IC_{50}$ and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10-4 M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

• The Korean Journal of Ecology
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• v.26 no.1
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• pp.5-12
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• 2003

Seed germination rate and seedling growth were measured on 6 different species(Phytolacca americana, Eupatorium rugosum, Rumex acetocella, Echinochloa crusgalli, Cassia mimosoides var. nomame, Setaria viridis) treated with leaf extract of E. rugosum. Total phenolic compound and heavy metal were analyzed on leaf and soil with and without E. rugosum. The growth of P. americana seedlings were stimulated by 10% and 25% of E. rugosum water extract treatment. The content of total phenolic compounds in soil was lower than that of leaf extract, and 25% was confirmed as threshold concentration in natural systems because the total phenolic compounds were not significantly different between the control soils and the soil treated with 10%, and 25% extract. Total phenolic compound concentrations of the leaf extracts were highest (1.66 mg/l) with E. rugosum grown under the Quercus forest canopy and lowest (1.09 mg/l) for the plant grown in the mixed forest edge. Leaf extracts of plants selected in different sampling sites (Forest interior, Forest edge, under Pinus Canopy and Quercus Canopy) were significant, while soil extracts were not. Seed germination of R. acetocella and S. viridis were significantly inhibited at over 50% concentrations of E. rugosum, but C. mimosoides var. nomame was not affected at any concentration. The radicle and shoot growth of the native species group were reduced two times more than those of the exotic species group by the treatment of extracts. Especially, the seed germination percentage and dry weight of E. rugosum were greater than those of the control group by treatments with extracts of 10% and 25%. Analysis of aqueous extracts from E. rugosum by HPLC identified 6 phenolic compounds: caffeic acid (460.9 mg/l), benzoic acid (109.7 mg/l), protocatechuic acid (7.3 mg/l), ρ-hydroquinone (6.0 mg/l), cinnamic acid (2.7 mg/l) and hydroquinone (0.23 mg/l). The seed germination of P. americana was also inhibited dramatically by protocatechuic acid and cinnamic acid even though the content of caffeic acid (460.9 mg/l) was the highest among analyzed phenolic compounds. The heavy metal content of soil without A. altissima was higher than that of soil with E. rugosum. Particularly, Al, Fe and Mn was considerably high and most of the heavy metal were accumulated in leaves where a high level of total phenolic compounds was found.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.258-264
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• 1988

Phenolic compounds present in upland weeds (Artemisia asiatica Nakai, Capsella bursa-pastoris (L.) Medik, Portulaca orleracea L. and Trifolium repens L.) which have shown allelopathic activity were determined using paper chromatography (PC) and high performance liquid chromatography (HPLC). Effect of the determined phenolic compounds on germination and post-germination growth of test plants was also investigated. Kinds of phenolic compounds determined by PC in the four weed species were greater in the aqueous extract than in the methanol extract. Ferulic acid was found in both extracts of the weeds studied, whereas benzoic acid was that the weeds commonly contained hydroquinone, p-hydroxybenzoic, ferulic and cinnamic acids. Out of the phenolic compounds determined by PC and HPLC p-hydroxybenzoic, cinnamic and ferulic acids inhibited germination and post-germination growth of radish and sesame. Inhibition of the phenolic compounds on the radicle growth was greater than on the germination of the test plants.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.339-345
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• 1994

Polyphenol oxidase in Yam was partially purified through ammonium sulfate fractionation, DEAE-cellulose column chromatography. The specific activity of purified PPO was 138.22 unit/mg protein. The optimum pH and temperature of purified PPO were respectively 7.0 and 30$^{\circ}C$. The heat treatment at 80$^{\circ}C$ for 6 min, decreased PPO activity to 50%. The enzyme showed high substrate specificity toward catechol. The Km value for catechol was 5 mM. In the Ames test using S. typhimurium TA98 and TA100 catechol-YEBRP, pyrogallol-YEBRP, chlorogenic-YEBRP showed strong antimutagenicity on sodium azide and MECF excepting hydroquinone-YEBRP showed killing effect on both strains.

• Korean Journal of Pharmacognosy
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• v.8 no.1
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• pp.17-21
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• 1977

$^{13}C-NMR$ behaviors of phenolic compounds such as phenol, catechol, pyrogallol, resorcine, phoroglucine and hydroquinone were studied. From the study on the effects of OH-substitution on benzene and its dervatives it was found that the additivity rule can be applied to the ortho-and para-effect but not to the meta-effect for the OH-function. The empirically calculated chemical shifts regarding the o-and p-effects coincide very well with the results of measurement. The chemical shifts of the phenolic compounds can be classified into three types. 1) Catechol-type C-1 and C-2 145 ppm C-3 and C-6 116-107 ppm 2) Pyrogallol-type C-1 132ppm C-2 and C-6 146ppm C-3 and C-5 106ppm 3) Resorcin-type C-1 and C-3 159ppm C-2 103-95ppm C-4 and C-6 107ppm

• Textile Coloration and Finishing
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• v.3 no.1
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• pp.28-36
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• 1991

Thermotropic behavior was observed in a number of aromatic copoly (ester amide)s containing a flexible spacer based on 4,4'$-dicarboxyalpha,\varpi-diphenoxy$ alkanes as an A component, di-acetylated p-aminophenol as a B, di-acetylated hydroquinone as a C gave the thermotropic copoly (ester amide)s containing a flexible spacer in the polymer backbone. 4,4'-diamino-3,3'-dimethoxybiphenyl as an amino group containing monomer as a D components. In the last case, up to 60 mol% of amide group was allowed to afford thermotropic liquid-crystallinity. The polymer structure and thermotropic nature were examined by solid-state and solution $^{13}C$ NMR spectroscopy, differential scanning calorimeter, polarizing microscopy, and IR spectroscopy.

• Journal of Plant Biology
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• v.32 no.1
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• pp.41-49
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• 1989

Phenolic compounds such as gallic acid, ferulic acid, p-hydroxybenzoic acid, vanillic acid, salicylic acid, tannic acid, and hydroquinone were identified from the aqueous extracts and volatile substances of tomato plant by paper chromatography, high performance liquid chromatography and gas chromatography. The seed germination and seedling growth of the experimental species, lettuce and egg plant, were severely inhibited in 5$\times$10-3M of phenolic reagents identical to those identified from tomato plant. Germination and growth rate of test species in 5$\times$10-4M and 5$\times$10-5M were higher than that of 5$\times$10-3M. Therefore, 5$\times$10-3M of phenolic compounds would be assumed to be threshold concentration for allelopathic effects.