• Composites Research
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• v.12 no.3
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• pp.75-83
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• 1999

The thermal properties of carbon/phenolic and silica/phenolic ablative composites were investigated by measuring the heat capacity, thermal diffusivity and thermal conductivity. The heat capacities of carbon/ phenolic and silica/phenolic composites were calculated from differential scanning calorimeter curve. The thermal diffusivities of carbon/phenolic and silica/phenolic composites were measured by the laser flash method with varying laminated direction, i.e., with laminar direction and across laminar direction. The thermal diffusivities decreased with increasing temperature. The thermal conductivities of carbon/phenolic and silica/phenolic composites were calculated using the heat capacity, density and thermal diffusivity. The thermal conductivities increased with increasing temperature. The thermal conductivity of with laminar direction is two times higher than that of across-laminar direction in carbon/phenolic composite due to the directionality of thermal conductivity of carbon fiber. The thermal conductivities of two dimensional fiber reinforced composites were analyzed using the conductivities of constituents and volume fraction of each constituent. The thermal conductivities of carbon fiber and silica fiber were calculated from thermal conductivities of carbon/phenolic and silica/phenolic composites. The thermal conductivities of carbon/phenolic and silica/phenolic composites at RT were predicted from thermal conductivities of fiber and resin with varying the volume fraction of fiber.

• Biomolecules & Therapeutics
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• v.17 no.3
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• pp.256-262
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• 2009

Smallanthus sonchifolius (Yacon, Asteraceae) was originally cultivated in South America and used in food and traditional medicine by Andean inhabitants. Yacon is potentially beneficial for the management of diabetes and is composed of fructooligosaccharides, proteins, minerals and phenolic compounds. The aim of this study was to investigate the hypoglycemic effect of Yacon tuber extract (YTE) and its constituent, chlorogenic acid (CGA), in streptozotocin (STZ)-induced diabetic rats. In this study, a HPLC method was developed for simultaneous determination of major active phenolic components, CGA and caffeic acid in YTE. We investigated the hypoglycemic effect of YTE and CGA in STZ-induced diabetic rats and studied glucose tolerance test (GTT). The effect of orally administered multiple doses of YTE and CGA on plasma biochemical parameters was examined using diabetic rats. We also measured free radical scavenging activity by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Oral administration of YTE (200 mg/kg) and CGA (10 mg/kg) for 6 weeks produced a significant hypoglycemic effect in STZ-induced diabetic rats. YTE and CGA-treated groups exhibited significantly decreased plasma glucose surge during the GTT. Total cholesterol (TC) and triglyceride (TG) concentrations were significantly decreased by 33% and 49%, respectively, in YTE-treated rats. TC and TG concentrations were also significantly decreased by 26 % and 41%, respectively, in CGA-treated rats. In the DPPH assay, free radical scavenging activity of CGA was similar to that of vitamin E, a positive control. This study suggests that YTE and its constituent, CGA, may be a useful option for management of hyperglycemia and diabetic nephropathy.

• Korean Journal of Pharmacognosy
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• v.38 no.3 s.150
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• pp.222-226
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• 2007

Seven compounds, scopoletin (1), p-hydroxyphenethyl trans-ferulate (2), $1-({\alpha}-L-rhamnosyl(1\;{\rightarrow}\;6)-{\beta}-D-glucopyranosyloxy)-3,4,5-trimethoxybenzene$ (3), benzyl ${\alpha}-L-rhamnopyranosyl(1\;{\rightarrow}\;6)-{\beta}-D-glucopyranoside$ (4), suberic acid (5), sebacic acid (6) and scopolin (7) were isolated from the methanol extract of the roots of Althaea rosea Canival. Compounds $1\;{\sim}\;7$ were first isolated from this plant. The isolated compounds were tested for their cytotoxicity against human cancer cell lines using a SRB method in vitro.

• The Korean Journal of Food & Health Convergence
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• v.4 no.2
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• pp.17-23
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• 2018

Carica papaya is an important medicinal plant used in the management of different disease conditions. Phytochemical screening was carried out using different chemical test, Percentage yield and total phenolic content was evaluated using Folin Ciocalteu method in different solvent system; methanol, ethanol, ethyl acetate, n-butanol and n-hexane respectively. The phytochemical screening of the studies showed the presence of flavonoids, saponins, tannins, terpenoids, glycosides, steroids, carbonhydrate, anthraquinone and alkaloids. The percentage yield of crude extract and total polyphenol content was high in methanol, ethanol and ethyl acetate when compared with n-butanol and n-hexane. The studies show that Carica papaya leave extracts is a potent source of secondary metabolites. The use of the plant in the management of diseases is justified.

• Biomolecules & Therapeutics
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• v.21 no.2
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• pp.153-160
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• 2013

We screened the pharmacological effects of a 50% ethanol extract of Yacon tubers and leaves on spermatogenesis in rats. As a result, we found that Yacon tuber extracts increased sperm number and serum testosterone level in rats. It has been reported that the crude extract of Yacon tubers and leaves contain phenolic acids, such as, chlorogenic acid, ferulic acid and caffeic acid by HPLC/MS analysis. We were interested in the contributions made by phenolic acid, particularly chlorogenic acid of Yacon tuber extract to the spermatogenic activity. After administering Yacon tuber extract or chlorogenic acid to rats for 5 weeks, numbers of sperm in epididymis were increased by 34% and 20%, respectively. We also administered ferulic acid, which has been reported to be a metabolite of chlorogenic acid and a constituent of Yacon tuber extract to investigate its spermatogenic activity in rats. Yacon tuber extract and ferulic acid increased sperm numbers by 43% and 37%, respectively. And, Yacon tuber extract, and chlorogenic acid showed significantly inhibition effect of testoeterone degradation in rat liver homogenate. We considered that the spermatogenic effect of Yacon tuber extract might be related to phenolic compounds and their inhibitory effect of testosterone degradation. Yacon showed the possibility as ameliorable agents of infertility by sperm deficiency and late onset hypogonadism syndrome with low level of testosterone.

• Biomolecules & Therapeutics
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• v.12 no.3
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• pp.138-144
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• 2004

Therapeutic effect of a Kampo medicine, Choto-san, in patients with vascular dementia was demonstrated by a double-blind and placebo-controlled clinical trial. To clarify the therapeutic efficacy of Choto-san, anti-ischemic effect in mice, hypotensive effect in spontaneously hypertensive rats (SHR), anti-oxidative effects in vitro, and N-methyl-D-aspartate (NMDA) receptor-blocking activity using Xenopus oocytes were studied. (1) Pretreatment with Choto-san (0.75-6.O g/kg, P.O.) or a component herb Chotoko (Uncaria genus: 75 - 600 mg/kg, P.O.) prevented ischemia-induced impairment of spatial learning behaviour in mice. Indole alkaloids- and phenolic fractions extracted from Chotoko also improved significantly the learning deficit. (2) Subchronic administration of Choto-san (0.5 g/kg, p.o.) caused a significant hypotensive effects in SHR. (3) Choto-san, Chotoko, and the phenolic constituent, (-) epicatechin, significantly protected the NG108-15 cell injury induced by $H_20_2$ exposure in vitro and also inhibited lipid peroxidation in the brain homogenate. (4) Indole alkaloids, rhynchophylline and isorhynchophylline (1-100 uM), reversibly reduced NMDA-induced current in the receptor-expressed Xenopus oocytes. These results suggest that anti-vascular dementia effects of Choto-san are mainly due to the effect of Chotoko. From these results, it is possible to make a novel dietary supplement through several extraction steps from Chotoko.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.141-151
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• 2012

The objectives of this research were to evaluate antioxidant activities and nutritional components, including phenolic acid, catechin, organic acid, sugar, and amino acid, of persimmon juice from persimmons grown in different regions around Korea. Persimmon (Diospyros kaki) exhibits potent antioxidant effects in DPPH, ABTS, reducing power, and FRAP methods of analysis. The levels of nutritional constituents showed significant differences among all the samples. In particular, tartaric acid, glucose, gallic acid, epicatechin gallate and aspartic acid were observed to be the predominant component for each of their general chemical groups, with total average contents of 1876.51 mg/kg, 62.69 g/kg, 12.73 mg/kg, 208.99 mg/kg, and 31.84 mg/100 g, respectively. Interestingly, persimmons from the Hadong region presented the highest sugar (130.60 g/kg), phenolic acid (42.27 mg/kg), and catechin (527.97 mg/kg) contents in comparison with other regional samples. Moreover, this location exhibited the greatest antioxidant activity with highest total phenolic (298.01 mg GAE/kg) and flavonoid (32.11 mg/kg RE) contents. Our results suggest that strong antioxidant activities of persimmons correlate with high phenolic acid and catechin contents, particularly gallic acid and epicatechin gallate. Additionally, these two compounds may be key factors when considering the useful ingredients of persimmon.

• Food Science and Preservation
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• v.30 no.6
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• pp.944-959
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• 2023

This study investigated the essential oil composition of fresh Panax ginseng root and identified novel compounds from ginseng oil. The oil was divided into five fractions (neutral, basic, phenolic, acidic, and aldehydic). In total, 149 constituents, including 29, 19, and 38 compounds in the basic, phenolic, and aldehydic fractions, respectively, were identified by gas chromatography (GC) and GC-mass spectrometry (MS). The primary constituents of the total ginseng volatile oil were α-humulene (13.91% as a peak area), bicyclogermacrene (13.59%), β-caryophyllene (8.24%), α-neoclovene (7.78%), and α- and β-panasinsenes (5.14% and 7.53%). The primary constituents of the basic fraction were 2-isopropyl-3-methoxypyrazine (35.51%), 3-sec-butyl-2-methoxy-5-methylpyrazine (31.54%), 2-isobutyl-3-methoxypyrazine (8.64%), and 2-methoxy-3-methylpyrazine (8.40%), whereas in the phenolic fraction, these were benzoic (25.40%), octanoic (11.57%), nonanoic (9.16%), propionic (6.35%), and decanoic acids (6.16%). The primary constituents of the aldehydic fraction were 4-(2-furyl)-3-buten-2-one (23.41%), benzaldehyde (10.18%), cis-2-heptanal (9.42%), 3-(α-furyl)-propenal (8.51%), and 2-phenyl-2-butenal (7.28%). Among these, the phenylalkenal compounds, including 2-phenyl-2-butenal, 2-methyl-3-phenyl-2-propenal, 5-methyl-2-phenyl-2-pentenal, 5-methyl-2-phenyl-2-hexenals, 2-phenyl-2-octenal, and 2-phenyl-2-nonenal, were newly identified in this study as ginseng volatile constituents. Furthermore, 2-phenyl-2-nonenal was identified as a plant-based volatile constituent for the first time in this study.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.114-122
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• 1995

Complexation experiment between humic acid and heavy metal cations was conducted to clear information on heavy metal adsorption by soil organic constituent. The absorbance of UV-visible light of humic acid-metal complexes increased with increasing wavelength, and the order of their absorbance was in the order of Zn->Cd->Cu- saturated humic acid. Carboxyl and phenolic OH groups participated in the complex formation between heavy metal cations and functional groups of humic acid, and the amounts complex was in the order of $Cu^{+{+}}$ > $Zn^{+{+}}$ $\geq$ $Cd^{+{+}}$. The stability constants of humic acid-metal complexes increased with increasing pH, and the order of first stability constants was $Zn^{+{+}}$ > $Cd^{+{+}}$ > $Cu^{+{+}}$, and those of second and overall stability constants were $Cu^{+{+}}$ > $Zn^{+{+}}$ > $Cd^{+{+}}$. With increasing pH, the average binding numbers betwen heavy metal cations and functional groups of humic acid increased the order of $Cu^{+{+}}$ > $Zn^{+{+}}$ > $Cd^{+{+}}$. It was postulated that two types of complexations between heavy metal cations and functional groups of humic acid. One was the reactions in which only carboxyl groups participated to form complexes, and the other was those in which both carboxyl and phenolic OH groups simultaneously participated.

• CELLMED
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• v.7 no.4
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• pp.16.1-16.2
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• 2017

Doronicum Hookeri of family Asteraceae is an important medicinal drug distributed in Himalayas at Lachen and Tungu, Sikkim, Nepal, Bhutan, Tibet between 12,000 to 14,000 ft. Its roots are widely used as folk medicine and are commonly known as "Darunaj-aqrabi" in Unani and as "Leopard's bane" in English. Roots are traditionally used as a constituent of, act as a stomachic and dissolves trapped gases. Antibacterial and antifungal activities of D. hookeri roots have been previously reported. The methanolic extract of root part possessed higher phenolic content and thus higher free radical scavenging and reducing activities. The methanolic extract of this plant showed scavenging and antioxidant activities in DPPH (2,2- diphenyl-1-picryhydrazy) radical scavenging assay.