• Journal of the Korean Chemical Society
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• v.10 no.4
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• pp.166-174
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• 1966

The multistep mechanism of photosensitized curing reaction cinnamoylated photosensitive polymer is proposed from the energy level diagram of cinnamic acid and sensitizer, and from the fact that excess of sensitizer brings the sensitivity to a limiting value etc. Various factors which have effects on the ability of sensitizer are also discussed. The mechanism involves following steps: activation to the first excited singlet states of cinnamoyl group(C) and sensitizer(S) by their absorption of photon, their intersystem crossing to the lowest triplet state, bimolecular internal quenching by formation of excimer of sensitizer, triplet excitation energy transfer and intermolecular addition between cinnamoyl group in ground state and that in triplet state. The rate equation derived from this mechanism is $-\frac{d[C]}{dt} = \frac{K_1[C]}{K_2 + [C]}[\frac{I^c_{abs}}{K_3 + [S]} + \frac{K_4[C]}{(K_5 + [C])(K_6 + [S])}(I^s_{abs} + \frac{K_7I^c_{abs}[S]}{K_8 + [S]})]$ where $I^c_{abs}\;and\;I^s_{abs}$: the rates of absorption of photon by cinnamoyl group and sensitizer $K_n$: Constants. It is proved with the cinnamate of poly(glyceryl phthalate)(PGC) in the absence of sensitizer using the infrared analytical method and successfully applied for the experimental data reported on the effects of the degree of cinnamoyl esterification and the concentration of sensitizer upon the sensitivity.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.396-404
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• 2010

Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at $25^{\circ}C$, $10^{-3}$ and $10^{-4}$ M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, O-coumaric acid, ${\rho}$-coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of O- and ${\rho}$-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination ($T_{50}$), phenolic compounds at $10^{-4}$ M promoted in Cyperus microiria and E. crus-galli but the level of $10^{-3}$ M delayed the $T_{50}$ of those weeds. The O-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.

• The Korean Journal of Food And Nutrition
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• v.25 no.4
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• pp.827-832
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• 2012

This study was conducted to develop HTHP ginseng (high temperature and high pressure ginseng) with improved antioxidative activity and phenolic acid composition by high temperature and high pressure process. The HTHP ginseng extract was analyzed for the total phenol content, DPPH radical scavenging activity and phenolic acid composition. The total phenol content was increased in HTHP ginseng (14.76 mg/g) compared to raw ginseng (3.59 mg/g) and red ginseng (3.93 mg/g). DPPH radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 4.8~78.4%, 1~47.4% and 1.8~56.5% at $1{\sim}100mg/m{\ell}$ concentration. Also ABTS radical scavenging activities of HTHP ginseng, raw ginseng and red ginseng extracts were 8.9~99.8%, 3.4~96% and 1.2~96.5% at $1{\sim}100mg/m{\ell}$ concentration. In HPLC analysis, amounts of measured phenolic acid of HTHP ginseng greatly increased than raw ginseng and red ginseng, but salicylic acid was not detected in HTHP ginseng. In addition, DPPH radical scavenging activity of phenolic acid from HTHP ginseng was increased. Consequently, we believe high temperature and high pressure process is better method than existing method to increase the bioactivity of ginseng.

• Preventive Nutrition and Food Science
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• v.21 no.2
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• pp.132-137
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• 2016

Enhanced production of individual phenolic compounds by subcritical water hydrolysis (SWH) of pumpkin leaves was investigated at various temperatures ranging from 100 to $220^{\circ}C$ at 20 min and at various reaction times ranging from 10 to 50 min at $160^{\circ}C$. Caffeic acid, p-coumaric acid, ferulic acid, and gentisic acid were the major phenolic compounds in the hydrolysate of pumpkin leaves. All phenolic compounds except gentisic acid showed the highest yield at $160^{\circ}C$, but gentisic acid showed the highest yield at $180^{\circ}C$. The cumulative amount of individual phenolic compounds gradually increased by 48.1, 52.2, and $78.4{\mu}g/g$ dry matter at $100^{\circ}C$, $120^{\circ}C$, and $140^{\circ}C$, respectively, and then greatly increased by $1,477.1{\mu}g/g$ dry matter at $160^{\circ}C$. The yields of caffeic acid and ferulic acid showed peaks at 20 min, while those of cinnamic acid, p-coumaric acid, p-hydroxybenzoic acid, and procatechuic acid showed peaks at 30 min. Antioxidant activities such as 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power values gradually increased with hydrolysis temperature and ranged from 6.77 to 12.42 mg ascorbic acid equivalents/g dry matter and from 4.25 to 8.92 mmol $Fe^{2+}$/100 g dry matter, respectively. Color $L^*$ and $b^*$ values gradually decreased as hydrolysis temperature increased from $100^{\circ}C$ to $140^{\circ}C$. At high temperatures ($160^{\circ}C$ to $220^{\circ}C$), L* and b* values decreased suddenly. The $a^*$ value peaked at $160^{\circ}C$ and then decreased as temperature increased from $160^{\circ}C$ to $220^{\circ}C$. These results suggest that SWH of pumpkin leaves was strongly influenced by hydrolysis temperature and may enhanced the production of phenolic compounds and antioxidant activities.

• Journal of Ginseng Research
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• v.31 no.4
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• pp.230-236
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• 2007

This study was conducted to investigate the contents of the total phenolic compounds, and DPPH, ABTS radical scavenging activities of phenolic acid fractions of ginseng according to steaming times. Also the individual phenolic acid compositions and contents were analyzed by GC. The contents of the total phenolic compounds proportionally increased from 0.530 to 2.893% according to steaming times. Phenolic acid fractions were separated according to bound types, and the insoluble bound form fraction showed the highest contents followed by ester form fraction and free form fraction. The total contents of these three fractions (1.031-1.416%) were not significantly influenced by steaming times. Salicylic, cinamic, p-hydroxybenzoic, gentisic, vanillic, syringic, caffeic, ferolic acid were found in each fraction, and gentisic and ferolic acid were the major phenolic acid. Each phenolic acid fraction showed over 50% of DPPH and ABTS radical scavenging activities. There were no differences between the phenolic acid fractions according to binding types. Free radical scavenging activities were affected by a number of steaming times and augmented as steaming times increased.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.435-442
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• 2001

Poly(3-hydroxy-5-phenylvalerate) [P(3HPV)] was efficiently accumulated from 5-phenylvalerate (5PV) in Pseudomonas putida BM01 in a mineral salts medium containing butyric acid (BA) as the cosubstrate. A nove aromatic copolyester, poly(5 mol% 3-hydroxy-4-phenylbutyrate-co- 95 mol% 3-hydroxy-6-phenylhexanoate) [P(3HPB-co-3HPC)] was also synthesized from 6-phenylhexanoate (6PC) plus Ba. The two aromatic polymers, P(3HPV) and P(3HPB-co-3HPC), were found to be amorphous and showed different glass-transition temperatures at $15^{\circ}C$ and $10^{\circ}C$, respectively. When the bacterium was grown ina medium containing 20 mM 5PV as the sole carbon source for 140 h, 0.4 g/l of dry cells was obtained in a flask cultivation and 20 wt% of P(3HPV) homopolymer was accumulated in the cells. However, when it was grown with a mixture of 2 mM 5PV and 50 mM BA for 40 h, the yield of dry biomass was increased up to 2.5 g/l and the content of P(3HPV) in the dry cells was optimally 56 wt%. This efficient production of P(3HPV) homopolymer from the mixed substrate was feasible because BA only supported cell growth and did not induce any aliphatic PHA accumulation. The metabolites released into the PHA synthesis medium were analyzed using GC or GC/MS. Two $\beta$-oxidation derivatives, 3-phenylpropionic acid and trans-cinnamic acid, were found in the 5V-grown cell medium and these comprised 55-88 mol% of the 5PV consumed. In the 6PC-grown medium containing Ba, seven ${\beta}$-oxidation and related intermediates were found, which included phenylacetic acid, 4-phenylbutyric acid, cis-4-phenyl-2-butenoic acid, trans-4-phenyl-3-butenoic acid, trans-4-phenyl-2-butenoic acid, 3-hydroxy-4-phenylbutyric acid, and 3-hydroxy-6-phenylhexanoic acid. Accordingly, based on the metabolite analysis, PHA synthesis pathways from the two aromatic carbon sources are suggested.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.232-237
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• 2008

Cinnamoyl-CoA reductase (CCR, EC 1.2.1.44) catalyses the reduction of cinnamic acid CoA esters into their corresponding aldehydes, the first step of the phenylpropanoid pathway specially dedicated to monolignol biosynthesis. A cDNA clones encoding CCR have been isolated from Panax ginseng C.A. Meyer and its expression was investigated in response to abiotic stresses. The cDNA, designated PgCCR which is 865 nucleotides long and has an open reading frame of 590 bp with a deduced amino acid sequence of 176 residues. The PgCCR encoded protein possesses substantial homology with CCRs isolated and cloned from other sources; the highest identity (51.8%) was observed with CCR from Tomato (Lycopersicon esculentum). Under various stress conditions, expression patterns of the PgCCR were highly induced in adventitious and hairy roots by several abiotic stresses. These results indicated that PgCCR plays protective role against diverse environmental stresses.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.240-248
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• 2014

Gyejibokryeong-hwan (GJBRH) has been used for treatment of patients with climacteric syndrome. In this study, an ultra-performance liquid chromatography-electrospray ionization-mass spectrometer (UPLC-ESI-MS) method was established for the simultaneous quantification of seven marker compounds in GJBRH extract. In addition, we assessed the antioxidant effects of GJBRH. All analytes were separated by gradient elution using two mobile phases on a UPLC BEH $C_{18}$ column and maintained at $45^{\circ}C$. The antioxidant activities of GJBRH were evaluated by measuring free radical scavenging activities on 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) and 1-1-diphenyl-2-picrylhydrazyl (DPPH). The inhibitory effects on low-density lipoprotein (LDL) oxidation were evaluated by the formation of thiobarbituric acid relative substances (TBARS) and relative electrophoretic mobility (REM). Regression equations of the seven compounds were acquired with $r^2$ values ${\geq}0.9988$. The amounts of the seven compounds, amygdalin, albiflorin, paeoniflorin, coumarin, cinnamic acid, cinnamaldehyde, and paeonol in GJBRH water extract were 21.71, 2.16, 17.17, 1.97, 0.40, 0.78, and 3.42 mg/g, respectively. The GJBRH showed the radical scavenging activity in a dose-dependent manner. The concentration required for 50% reduction ($RC_{50}$) against ABTS and DPPH radicals were $54.18{\mu}g/mL$ and $79.53{\mu}g/mL$. Furthermore, GJBRH reduced the oxidation properties of LDL induced by $CuSO_4$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.2
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• pp.85-94
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• 2022

The mixed cropping system is a centuries-old cropping technique widely practiced in farmers' fields worldwide. Increased plant diversity enhances farmland biodiversity, which improves grain yield and quality. However, the effect of growing different rice cultivars simultaneously has rarely been investigated. In the present study, six glutinous rice cultivars were selected, and two mixture cultivation methods were determined according to plant height, grain yield, and color. Colored and glutinous rice are used for specific purposes by consumers because of their color and nutritive value. Six glutinous rice varieties, including aromatic and colored rice, were included in the combination interplanting trials. The results showed that, compared with the corresponding monocropping systems, almost all combinations of the mixed cropping systems had advantages in yield-related traits. Compared with monocropping systems, mixed cropping systems increased the number of panicles per plant and maturation rate by 20% and 10%, respectively. An increase of 18-20% grain yield was observed in mixed cropping plots compared with that in plots which grew only a single rice variety. Some rice varieties, such as green colored rice 'Nogwonchall' and black colored rice 'Chungpunghukhayangchall', exhibited 18-22% increased yield when they were planted in combinations. The high yields were primarily owing to improved light interception and reduced lodging, although other factors (for example, reduced severity of disease) may have also contributed.

• The Korean Journal of Food And Nutrition
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• v.31 no.1
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• pp.135-142
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• 2018

We investigated the influence of germination and high hydrostatic pressure (HHP) treatment conditions on the conversion of functional compounds and antioxidant activity in adzuki bean. The adzuki bean germinated at $25^{\circ}C$ for three- or six-days, and was later subjected to HHP at 0.1, 50, 100, or 150 MPa for 24 h. The highest polyphenol content (5.36 mg gallic acid equivalents (GAE)/g) and flavonoid content (0.91 mg catechin equivalents (CE)/g) were observed after germination for six days and HHP treatment at 100 MPa for 24 h, respectively. The total phenolic acid contents increased with increasing applied pressure from 88.86 to $208.26{\mu}g/g$ (100MPa, 24h). Phenolic acids are divided into two categories; those that exhibit increased content upon HHP treatment, and those that exhibit decreased content. The increasing phenolic acids were gallic acid, chlorogenic acid, (+)-catechin, ${\rho}-coumaric$ acid, ferulic acid, heperidin, salicylic acid, protocatechuic acid, cinnamic acid, naringenin. The total anthocyanin content decreased with increasing applied pressure from 22.42 mg/100 g to 6.28 mg/100 g (150 MPa, 24 h). The highest ABTS radical scavenging activity (8.02 mg eq AA/g) and DPPH radical scavenging activity (1.22 eq Trolox/g) were observed after germination for six days and HHP treatment at 100MPa for 24h, respectively. These results suggested that the combination of HHP and germination can lead to improved functionality in adzuki bean.