• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.372-380
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• 1996

This study was carried out to study the resistant substances to pine needle gall midge and seasonal variation of phenolic compounds in pine needles among susceptible and resistant species to pine needle gall midge. Free and water soluble phenolic compounds contained in pine needles showed seasonal variations among pine species. But, catechol, vanillic acid and syringic acid including phenolic compounds showed no variation between pine species, even the amount of those component varied by the seasons. Salicylic acid in pine needles showed 140ppm in Pinus virginiana, 35ppm in Pinus thunbergii and 72ppm in hybrid pine, Pinus thunbergii${\times}$P. virginiana, but traces in Pinus densiflora on May and June, hatching season in larvae of pine needle gall midge. There was high level of salicylic acid in resistant species to pine needle gall midge but traces in susceptible species. As our previous researches, the necrosis rate of larvae of pine needle gall midge showed high level on the solution of phenolic compounds extracted from needles of P. virginiana and salicylic acid, and there was no gall formation in P. virginiana, so that salicylic acid in pine needles seems to have relation with those results. Therefore, it is estimated that salicylic acid is resistant substance to pine needle gall midge.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.290-290
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• 2017

Rice (Oryza sativa L.) is one of the most consumed staple food crop which is energy source as carbohydrate and also is considered as the important antioxidant sources including various phenolic compounds. According to the increasing demand of healthy life, the concern to antioxidant also is increasing because of its health-promoting effect. Phenolic compounds are one of the plant secondary metabolites class, which shows various benefits to preventing or treating chronic diseases. In this study, we have measured the total phenol content from total 647 rice samples using the Floin-Ciocalteau method, and then were selected 30 rice genetic resources classified with high, middle, and low group on the basis of total phenol content. The average of the total phenol content of each group was high-group ($6892.9{\pm}488.5{\mu}g\;GAE/g$) > middle-group ($1428.1{\pm}76.0{\mu}g\;GAE/g$) > low-group ($97.6{\pm}11.4{\mu}g\;GAE/g$). The selected rice samples were analyzed with LC-MS/MS to find the composition and concentration of individual phenolic in rice grain. High-group and middle-group contained large amounts of protocatechuic acid and (+)-catechin whereas low-group showed limited amount. Among high-group samples, rice samples with black pericarp color (IT 174089, IT 220079, and IT 259958) had high content of peonidin-3-O-glucoside. Further, these black rice samples were special since polydatin, rarely found stilbenoid in rice grain, was detected. Overall, both the sum of phenolic acid and the sum of flavonoid were high-group > middle-group > low-group. Also, each group exhibited different phenolic compositions; high-group consisted of flavonoid more than phenolic acid, middle-group and low-group was comprised of phenolic acid rather than flavonoid, and non-pigmented rice was composed by fully phenolic acid. The total phenol content had positive relationships with the sum of phenolic compound (r = 0.64), the sum of flavonoid (r = 0.74) at the significance level of p < 0.0001. In addition, protocatechuic acid and quercetin showed positive correlation with above phenolic composition parameters; in order, r = 0.98, 0.65 for protocatechuic acid and r = 0.73, 0.78 for quercetin (p < 0.0001). In conclusion, the total phenol content assay showed the possibility of utilization as a phenolic composition indicator in rice grain. Also, this result was suggested study pigment on other material.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.232-239
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• 1996

Phenolic compounds are known to inhibit the nitrosation or oxidation reaction. In the present work, the effects of phenolic compounds including phenolic acids and flavonoids on the nitrite-scavenging and electron donating ability were tested as scavenger of nitrite which is believed to participate in the formation of N-nitroso compounds and investigated as electron donator. The nitrite scavenging ability appeared in all the phenolic acids and showed the highest value at PH 1.2. Among the Phenolic compounds, phenolic acids showed higher nitrite-scavenging action than some flavonoids. Futhermore, the nitrite scavenging action of phenolic compounds was pH dependent highest at pH 1.2 and lowest at pH 6.0. The electron donating ability (EDA) by reduction of ${\alpha},{\alpha}$-diphenyl-${\beta}$-picrylhydrazyl (DPPH) among hydroxybenzoic acids was in the decreasing order of gallic acid, gentisic acid, syringic acid, protocatechuic acid, salicylic acid, vanillic acid, benzoic acid and p-hydroxybenzoic acid. EDA of hydroxycinnamic acids was in the decreasing order of hydrocaffeic acid, caffeic acid, ferulic acid, p-coumaric acid and trans-cinnamic acid. EDA of flavonoids was in the decreasing order of (+)catechin, rutin, quercetin, naringin and hesperidin. Other phenolic compounds were significantly high in electron donating abilities.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.11-19
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• 2003

Allelopathic effects of black locust(Robinia pseudoacacia L.) was evaluated through germination tests using 13 different species including R. pseudoacacia itself. The water extract from leaf or root of R. pseudoacacia was separately tested. Seed germination of several species was inhibited in the presence of leaf or root extract, although the level of germination was in a wide range depending on the species. Seed germination of R. pseudoacacia was suppressed by 30 % in its leaf extract. Among tested tree species, Hibiscus syriacus and Alnus frma showed significantly inhibited germination in the root extracts whereas Thuja orientalis exhibited germination inhibition in the leaf extract. HPLC was carried out to identify allelochemicals in extracts of leaf and root using eight authentic phenolic compounds that are known to be responsible for allelopathy. The major phenolic compounds occupying about 40 % of total phenolic acids were gentisic acid in leaves and vanillic acid and syringic acid in roots. The leaves contained 7 times more phenolic acids than the roots. Among 8 tested phenolic compounds vanillin was detected only in roots and coumaric acid in leaves. Consequently, 3 out of 13 species showed significantly inhibited germination due to leaf or root extract. This germination test indicates that the inhibitory allelopathic effect by R. pseudoacacia is caused by chemical interaction not by nutritional competition and that the allelochermicals of black locust act species-specifically. No specific influence of the total amount of phenolic compounds on the allelopathic inhibitory germination and the synergic effect by each phenolic compound may play a role for the allelopathic effect by R. pseudoacacia.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.64-64
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• 2019

Screening and identification of genetic resources based on their phytoconstituents and morphological characters potentially provide baseline data for researchers, breeders, and nutraceutical companies who wish to formulate a nutrient-dense diet and health beneficial supplement. Thus, we evaluated the amount of total phenolic content and major phenolic compounds; examined if phenolic compounds could be used as distinguishing factors for perilla genetic resources; and investigated the relation between some quantitative and qualitative morphological characters with the contents of phenolic compounds in 360 accessions obtained from National Agrobiodiversity Center gene bank, Jeonju, Korea. Total phenolic content (TPC) was estimated using Folin-Ciocalteu colorimetric assay. Individual phenolic compounds were determined using an Ultra-High Performance Liquid Chromatography system equipped with Photodiode Array detector. Considerable variations were observed in TPC (7.99 to 117.47 mg GAE/g DE), rosmarinic acid (RA) (ND to 19.19 mg/g DE), caffeic acid (CA) (ND to 0.72 mg/g DE), apigenin-7-O-diglucuronide (ADG) (ND to 1.24 mg luteolin equivalent (LUE)/g DE), scutellarein-7-O-glucuronide (SG) (ND to 4.32 mg LUE/g DE), and apigenin-7-O-glucuronide (AG) (ND to 1.60 mg LUE/g DE). RA was the most dominant phenolic compound in most accessions (95.3%) followed by SG. The adaxial leaf color was light green, green and dark green in 13.8%, 65.0%, and 21.1 % of the accessions, respectively. 78.8% of the accessions had light green color at the abaxial side with the remaining being described as green. Most of the accessions (96.9%) were cordate shape, the remaining being eclipse. Intensities of green pigment at abaxial and adaxial leaf surfaces were correlated with contents of individual phenolic compounds and TPC whereas leaf length and width had no correlation with TPC, CA and RA, and negatively correlated with ADG, AG, and SG. Leaf shape was not related with content of phenolic compounds, color of leaves, or the length or width of leaves. Accessions IT57426, IT157434, IT267710, and IT267712 which contained relatively high contents of TPC and major phenolic compounds (RA and SG) could be used for further research in breeding and bioassay test. Our study result showed the contents of total phenolics and individual phenolic compounds along with the morphological characters could be useful distinguishing factors for perilla genetic resources.

• Natural Product Sciences
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• v.6 no.2
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• pp.82-85
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• 2000

The aqueous ethanolic whole plant extract of Rosa arabica was found to contain the new natural dimeric phenolic compound, ellagic acid 3,3'-dimethyl ether $4-O-{\alpha}-rhamnopyranoside$, 9, along with ten known phenolic metabolites (1-8, 10 and 11). Structures of all compounds (1-11) were established by routine methods of analysis and confirmed by FAB-MS, $^1H\;and\;^{13}C$ NMR spectral analysis.

• Food Science and Preservation
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• v.24 no.2
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• pp.282-288
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• 2017

This study provided the evidence activity for biological of phenolic compounds from Trachelospermum asiaticum var. intermedium nakaier as a beauty food. The contents of phenolic compounds in water and 70% ethanol extracts were 16.8 mg/g and 38.1 mg/g, respectively. DPPH free radical scavenging activities of water and ethanol extracts at $100{\mu}g/mL$ of phenolic concentration were 80.9% and 83.1%, respectively. ABTS radical decolorization activity was 95.0% in water extracts and 95.8% in ethanol extracts at $200{\mu}g/mL$ phenolic concentration. Antioxidant protection factor (PF) was determined to 2.43 and 2.45 PF in water extracts and ethanol extracts at $100{\mu}g/mL$ phenolic concentration. TBARs of water and ethanol extracts were 89.9% and 89.3% each at $200{\mu}g/mL$ phenolic concentration. The inhibitory effect of ethanol extracts at $200{\mu}g/mL$ phenolic concentration on xanthine oxidase was 50.5%. The inhibitory activity of a-glucosidase was 92.6% in ethanol extracts at $200{\mu}g/mL$ phenolic concentration. As a result, this study will provide valuable information as a functional material with antioxidant activity, inhibitory activities of xanthin oxidase and ${\alpha}-glucosidase$.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.310-316
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• 2020

Terpene-modified phenolic resins were used to improve the tires wet traction related to the driving safety and also rolling resistance related to fuel efficiency. In this work, alpha-pinene, beta pinene, and delta limonene resins, which constitute different basic structures of terpene-modified phenolic resins, were individually added to the tread compounds of tires and their physical properties were compared with those of the alkyl phenol resin compounds. Alkyl phenolic resins showed no significant difference in tangent delta from terpene-modified phenolic resins at 0 ℃, which is related to wet traction, but showed higher tangent delta at 80 ℃, which is related to rolling resistance, indicating smaller fuel efficiency improvement effects. Among the terpene-modified phenolic resins, beta pinene one showed improved wet traction and fuel efficiency compared to those of other resins. Delta limonene resin showed the best wet traction improvement effect, and alkyl phenolic resins showed relatively high tensile strength and abrasion property. All terpene-modified resins exhibited better rolling resistance than those of alkyl phenolic ones so that they can be said to have better fuel efficiency improvement effects and also to improve other properties compared to those of blanks. Terpene-modified phenolic resins could be used when mixing tire compounds referring to the properties of the phenolic resins revealed in this work, which could result in preparing compounds with improved wet traction and rolling resistance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.6
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• pp.1107-1111
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• 2002

This study has been carried out to investigate the effects of the Phenolic compound on the hyperglycemic mice induced with strentozotocin (STZ). The effects of the phenolic compound were assayed by the changes of the blood glucose creatinine and blood urea nitrogen (BUN ) levels, and insulin-immunohistochemical staining and electron microscopical observation for $\beta$ -cells of the Langerhan's islet, under the same experimental conditions. For this purpose male mice were fed with phenolic compound (PA group, IS mg/kg/day; PB group, 90 mg/kg/day)in their diet while the control group received the same commercial diet, for 6 weeks. The blood glucose contents was examined by tail vein blood once a week for 6 weeks. Samples of the pancreas removed after that period were processed for the immunohistochemical identification of $\beta$ -cells as well as for measuring ultrastructural changes of $\beta$-cells. The levels of serum glucose were decreased significantly (p<0.05) on the PB group compared with the control and PA group. The blood BUN and creatinine levels are slightly decreased in the phenolic compound feeding groups compared with control group. The $\beta$-cells on Langerhnan's islet were destructed by administration of STZ, so that a few of insulin-positive cells were observed in the control group. A lot of insulin-positive cells were observed in the PB group compared with the control group. According to the electron microscopical observation $\beta$-cells are recovered from the damage in the PA group. The $\beta$-cell contained a lot of electron dense and pale granules compared with control group. These results suggest that administration of the pear phenolic compound to the mice helped recovery from the damage induced by STZ.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.164-169
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• 2002

Five kinds of red wine from three different grape varieties, such as Gerbong (G), Campbell (C), Moru (M), Gerbong+Moru (70:30, GM), and Gerbong+Campbell(70:30, GC) were prepared in the year of 2000. The total phenolic content and color changes were monitored using hunter colorimeter and spectrophotometry methods during wine processing. The total phenolic content of Gerbong (G), Campbell (C), Moru (M), Gerbong+Moru(70:30, GM), and Gerbong+Campbell(70:30, GC) were 712.6 mg/L, 3472.9 mg/L, 2209.4 mg/L, 2019.4 mg/L, and 1184.5 mg/L, respectively. Between total phenolic content and hunter colorimeter value (L, a, and b) of red wine showed no significant difference, but that of spectrophotometry color value (hue and intensity) were significantly different (p<0.001). The total phenolic content, hue, and intensity values represented significantly different between grape varieties (p<0.01, p<0.001). the hue showed a negative correlation relationship $(r^2=0.8660,\;p<0.0001)$, and that of intensity was a positive $(r^2=0.8304,\;p<0.0001)$ between total phenolic contents. The total phenolic content of red wine could be estimated simply using these equations, $Y_{Total\;phenolic\;content\;(mg/L)}=3319.3-X_{Hue}/2208.36,\;and\;Y_{Total\;phenolic\;content\;(mg/L)}=1230.97-X_{intensity}/98.93$