• Korean Journal of Weed Science
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• v.5 no.2
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• pp.121-130
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• 1985

The phenolic compounds identified from rye and wheat residues seemed to be p-coumaric, p-hydroxybenzoic, vanillic, ferulic, salicylic and syringic acids. Total phenol content of rye and wheat straw determined at heading stage was 0.1803% and 0.1702%, respectively. Total phenol content in straw was higher than that of root at all growth stages. The germination and growth of plants, such as Oryza sativa, Echinochloa creugalli, Cyperus serotinus, Portulaca oleacea, Amaranthus retroflexus, Digitaria saguinalis, and C. album were inhibited by treatments of authentic phenolic compounds as the concentrations increased. However, at the early stage, the germination and shoot growth of P. distinctus were markedly stimulated by them, and then the further growth of shoot and root was markedly inhibited by the prolonged treatment of phenolic compounds. The aqueous extracts from rye and wheat straw completely inhibited the germination of A. retroflexus and C. album at a high concentrations. The content of starch and protein in bulbs of P. distinctus was lower in the p-hydroxybenzoic acid treated plot, at $10^{-2}M$, than the untreated control.

• Korean Journal of Pharmacognosy
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• v.48 no.3
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• pp.208-212
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• 2017

In this study, analysis of active compounds that are believed to be highly relevant to antioxidant activity was carried out on the methanol extract and its solvent fractions of Corni fructus. The DPPH radical scavenging activity for the comparison of antioxidant activity was higher in order of aqueous fraction > methanol extract > ethyl acetate fraction > n-hexane fraction. It is similar to the order of total polyphenol contents in the samples. As a result of LC-MS analysis, phenolic acid compounds such as caffeic acid, gallic acid and chlorogenic acid and lognin, which is known as a representative active ingredient of Corni fructus, were identified as active compounds. And the antioxidative activity and the total polyphenol content of the extracts and solvent fractions were found to be related to the contents of the compounds. Particularly, it was confirmed that phenolic acid such as caffeic acid contributes to the antioxidative activity of the aqueous fraction of Corni fructus methanol extract.

• Natural Product Sciences
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• v.29 no.1
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• pp.24-30
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• 2023

Adenanthera pavonina L. is an important medicinal plant for Indonesian traditional medicine ("Jamu"). The present study is to determine the phenolic content and evaluate the antioxidant activity of ethyl acetate and ethanolic extracts of leaves and bark of A. pavonina. The total phenolic content was determined using the Folin-Ciocalteu reagent methods, and the antioxidant activity was performed by phosphomolybdate assay, through EC₅₀ values. The highest phenolic content (81.379 mg GAE/g) was found in the hydro-ethanolic extract of the leaves and (80.630 mg GAE/g) in the bark. The antioxidant activity of the two samples was 42.270 ㎍/mL (leaves) and 45.261 ㎍/mL (bark). Plants have the potential as drugs with good antioxidant potential and phenolic compound content. Further scientific studies of this plant are supported to evaluate the antioxidant activity using other methods to validate these preliminary experiments properly.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.809-827
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• 2017

Steam explosion was applied to extract phenolic compounds from oak wood (Quercus mongolica). The effects of three independent factors (ethanol concentration, extraction temperature and extraction time) on the total phenolic content, DPPH radical scavenging activity, and antimicrobial activity from the steam exploded oak wood were optimized using response surface methodology (RSM). The independent variables were coded at three levels and their actual values were selected on the basis of preliminary experimental results. The following optimal extraction conditions were selected: ethanol concentration 82.0%, extraction temperature $71.7^{\circ}C$, and extraction time 60.5 min for total phenolic content; ethanol concentration 78.3%, extraction temperature $70.3^{\circ}C$, and extraction time 57.6 min for DPPH radical scavenging activity; ethanol concentration 80.6%, extraction temperature $68.4^{\circ}C$, and extraction time 59.0 min for antimicrobial activity. The experimental values agreed with those were predicted within confidence intervals indicating the suitability of RSM in optimizing the ethanol extraction of phenolic compounds from the steam exploded oak wood. Under the optimized conditions, the experimental value of the total phenolic content was 111.8 mg GAE/g dry steam exploded oak wood, DPPH free radical scavenging activity was 65.7%, and antimicrobial activity was 17.0 mm, and those are reasonably close to the predicted values (109.2 mg GAE/g dry steam exploded oak wood, 62.3% and 15.9 mm, respectively).

• Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.12-17
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• 2010

This study was conducted to evaluate the potential of a microbial fermentation procedure to improve the functional qualities of seaweeds. Aspergillus oryzae, which has been used in traditional Korean fermented foods, was inoculated and cultivated in an aqueous extract of sea tangle (Laminaria japonica). Fermentation of the sea tangle extract by A. oryzae for 4 days resulted in a 3-fold increase in $\gamma$-aminobutyric acid (GABA) content. GABA is known to be a bioactive compound. Fungal fermentation of the extract also enhanced its antioxidant activity and increased its total content of phenolic compounds. It was assumed that these changes stemmed from the biodegradation of active compounds of the sea tangle packaged within its rigid structural matrix or occurred as result of fungal fermentation. These results suggested that the application of microbial fermentation to the processing of seaweeds will help in the development of processed foods to meet consumer demands.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.2
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• pp.116-120
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• 2004

In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.102-107
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• 2002

Cereal grains are rich in phenolic compounds that give beneficial effect in human health. Although several research works have been reported on the effects of phytochemicals of plant origin, such as fruits, vegetables, few studies have examined the antioxidative effects of whole cereal grains. The objective of this study was to determine total antioxidant capacity of 80% ethanolic extracts of cereal grains by testing the ability of the extracts to inhibit UV -induced lipid peroxidation in vitro using linoleic acid in comparison to well-known antioxidant such as ascorbic acid and tannic acid. The total phenolic content of the cereal grain (80% ethanolic extracts) investigated in this study varied from 2.1 mg/g (wheat cv. Olgeurumil) to 10.4 mg/g (barely cv. Seodunchalbori). Highly positive relationship between total phenol compounds and antioxidant activity was found. When the antioxidant activities of all investigated extracts were measured with application of same quantity of phenol compounds, oat grain extracts showed similar antioxidant activity of barely cultivars. However, barely extract appeared as the most potent antioxidant activity of inhibition of UV -induced lipid peroxidation. This indicated that factors such as phenolic compound composition and their individual antioxidant activity could playa crucial role in the total antioxidant activity of cereal grains.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.535-547
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• 2015

In this study, the chemical properties and phenolic compound of blueberry, bokbunja and mulberry and their pomace were determined to develop them as functional food materials. Water content of individual whole berry was ranged from 84.25-86.20%, and water content was significantly high in whole berries rather than their pomace (p<0.01). Additionally, each berry and its pomace's pH was 3.32-5.18. Among them, whole mulberry showed the highest pH which is 5.18 (p<0.01). Total polyphenol and flavonoid contents were the greatest in blueberry pomace and they were 24.81 mg/g and 2.13 mg/g, respectively (p<0.01). However, mulberry pomace generated the greatest anthocyanin content compared to others (p<0.01). In phenolic compound profiles, cyanin chloride was detected in mulberry and bokbunja. Epigallocatechin, gallocatechin and isorhamnetin were found only in blueberry. Catechin (hydrate) and epicatechin were greater in pomaces than whole berries except blueberry (p<0.01), otherwise, significantly great rutin (trihydrate) and quercetin contents were found in whole berries as compared to their pomace except blueberry (p<0.01). Gallic acid was significantly greatest in mulberry (p<0.01) and quercetin 3-D-galactoside was significantly greatest in blueberry (p<0.01). Apigenin and luteolin were traced in mulberry, and mulberry pomace showed greater apigenin and luteolin contents than whole mulberry (p<0.01). Naringenin was greater in pomaces than whole berries (p<0.01). As a result, it was found that all berry extracts used in this study were able to be applied as functional food materials and their pomace contained high phenolic compound enough to be a good source of phytochemical for nutraceutical use.

• 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.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.107-111
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• 2001

Physical and chemical characteristics of four white-and one yellow-fleshed peach cultivars were compared at optimum maturity stage. In addition, differences of phenolic composition, polyphenol oxidase (PPO) activities and PPO isozyme patterns in two peach types were also investigated. There are no significant differences in firmness and color values between two peach types, except for "Yumyung", a white-fleshed peach with the highest firmness, and "Hwangdo", a yellow-fleshed peach with the highest yellowness (b)* value. In general, the soluble solid/titratable acidity ratios, ascorbic acid and total phenolic contents were significantly higher for white-fleshed peaches than those for yellow-fleshed peach (p<0.05). Three major phenolic compounds, catechin, neochlorogenic acid and chlorogenic acid, were found in both the white-and yellow-fleshed peaches. Among them, catechin was the predominant phenolic compound in the white-fleshed peaches, followed by neochlorogenic acid, and chlorogenic acid. Meanwhile, neochlorogenic acid was present in the highest level of the yellow-fleshed peach, but levels of two other phenolic compounds were lower. PPO activities of the white-fleshed peaches were generally higher than that of the yellow-fleshed peach, with the one major band and two minor bands, and there were no big differences in PPO isozyme patterns between two different peach cultivars.