• YAKHAK HOEJI
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• v.50 no.6
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• pp.351-357
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• 2006

Polygoni Radix (Polygonaceae) has been used as renal disoder hematopoietic, menstrual irregularity and antiaging in Korean folk medicine. Specially aerial parts has been used for insomnia and sedative agent. In order to investigate the efficacy of antioxidant activity on these aerial parts, the bio-activity guided fraction and isolation of physiologically active substance were performed. H$_2$O, 30%, 60%, 100% MeOH were examined antioxidant activity by DPPH method. It was revealed that 30%, 60% MeOH fractions have significantly antioxidant activity. From 60% MeOH fraction, six known flavonoid glycosides (quercetin, quercetin 3-O-${\beta}$-D-galactopyranosyl-4'-O-glucopyrano side-3'-methyl ether, quercetin 3-O-${\alpha}$-L-rhannopyranoside, quercetin 3-O- ${\alpha}$-L-rhamnopyranoside-4'-methylethor, quorcetin 3-O-${\beta}$-D-galactopyranoside, quercetin 3-O-${\beta}$-D-galactopyranoside) and 3,4-Oihydrocinnarnic acid were isolated. To investigate the antioxidant activities of each com-pounds, we measured radical scavening activity with DPPH method and anti-lipid peroxidative efficacy on low density lipo-protein (LDL) with TBARS assay and anti-acetylcholinestrase activity with Ellman's Test. Four compounds (ll, IV Vl, Vll) of quercetin glycosides showed significant activity.

• Journal of Mushroom
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• v.16 no.3
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• pp.170-174
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• 2018

This study aims to investigate the antifungal and protective effects of water- and 70% methyl alcohol-extracts from spent mushroom substrate (WESMS and MeOHSMS) of Lentinula edodes, on Botrytis cinerea- the causative agent for gray mold disease in ginseng. MeOHSMS inhibited mycelial growth and spore germination of Botrytis cinerea, by 75% and 95%, respectively. MeOHSMS could suppress gray mold disease of ginseng seedlings by 80% and effectively reduce the disease severity by 60%. Compared to the treatment of ginseng leaves with WESMS and DL-${\beta}$-aminobutyric acid (BABA), the MeOHSMS treatment increased the phenolic compounds in the leaves by 36% and 18%, respectively. These results suggest that the SMS extracts suppress gray mold disease in ginseng via dual functions: antifungal activity and increase in a plant defense factor-phenolic compounds.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.54-54
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• 2003

Prostate gland contains neuroendocrine cells (PNECs) are playing important roles in physiological and pathophysiological processes of the prostate gland. Here, we investigated the role of purinoceptors in PNECs freshly isolated from rat ventral prostate (RPNECs) that show immunoreactivity to chromogranin A. Fura-2 ratiometry revealed that ATP evokes both fast Ca$\^$2+/ influx and store Ca$\^$2+/ release in RPNECs. A whole-cell patch clamp study demonstrated fast inactivating cationic current activated by ATP or by ${\alpha}$,${\beta}$-MeATP, which was blocked by ATP-TNP. The activation of P2X inward current was tightly associated with a sharp increase in [Ca$\^$2+/]$\sub$c/. The presence of P2X1/3 subtypes were proved by RT-PCR analysis. For the stored Ca$\^$2+/ release, ATP and UTP showed similar effects, suggesting the dominant role or P2Y2 subtypes, also confirmed by RT-PCR. Both P2X (${\alpha}$,${\beta}$-MeATP) and P2Y (UTP) stimulation induced changes in the cell morphology (initial shrinkage and blob formation on the surface) reversibly. Exocytotic membrane trafficking events were monitored with the membrane-bound fluorescent dye, FM1-43 using confocal microscopy. In spite of the similar Ca$\^$2+/ responses, UTP was far less effective in triggering exocytosis than ${\alpha}$,${\beta}$ -MeATP. Since serotonin is reportedly stored in the secretory granule of PNECs, we directly examined whether the aforementioned agonists elicit release of serotonin using carbon fiber electrode-amperometry. In accordance with the results of FM1 -43 experiments, ${\alpha}$,${\beta}$-MeATP efficiently evoke serotonin secretion while not with UTP. In summary, the P2X-mediated Ca$\^$2+/ influx plays crucial roles in the exocytosis of RPNECs. Although a global increase in [Ca$\^$2+]$\sub$c/ might be related with the morphological changes, a sharp rise of [Ca$\^$2+/]$\sub$c/ in the putative sub-plasmalemmal ‘microdomains’ might be a decisive factor for the exocytosis.

• Journal of Life Science
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• v.29 no.2
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• pp.231-238
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• 2019

This study evaluated the antioxidant activity of the extract and fractions of Alnus firma. Alnus firma had the highest total phenolic content ($452.80{\pm}7.01{\mu}g$ gallic acid equivalents/mg) in a methanol (MeOH) fraction and the highest total flavonoid content ($112.29{\pm}11.14{\mu}g$ rutin equivalents/mg) and antioxidant capacity ($936.23{\pm}0.07{\mu}g$ ${\alpha}$-tocopherol equivalents/mg) in an ethylacetate (EA) fraction. The antioxidant activities of various solvent extract fractions of Alnus firma were evaluated using various antioxidant assays, including ${\beta}$-carotene-linoleate assay, reducing power assay, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, metal chelating activity assay, superoxide anion radical scavenging assay, and lipid peroxidation inhibition assay using the ferric thiocyanate method. These activities were compared with those of ascorbic acid, butylated hydroxyanisole (BHA), gallic acid (GA), butylated hydroxytoluene (BHT), and ${\alpha}$-tocopherol. First, at a $250{\mu}g/ml$ concentration, the EA and MeOH fractions of A. firma showed 92.43% and 89.20% DPPH radical scavenging activity, respectively. Second, $50{\mu}g/ml$ of the EA fraction exhibited 72.49% superoxide anion radical scavenging activity, a little greater than the same dose of GA (60.88%). Finally, 0.5 and 1 mg/ml of the EA fraction showed 73.45% and 73.29% inhibition of peroxidation in the ${\beta}$-carotene-linoleic acid system, respectively. The decreasing order of reducing power was EA fraction > n-butanol (BuOH) fraction > dichloromethane (DCM) fraction > n-hexane (HX) fraction. The results obtained in the present study indicated that Alnus firma can be used as an easily accessible potential source of natural antioxidants.

• Korean Journal of Crystallography
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• v.18 no.1_2
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• pp.1-6
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• 2007

An Organometallic compound, $C_{16}H_{35}B_{10}IrS_2Si$, was synthesized from o-carborane, $Cp^*Ir(S_2C_2B{10}H_{10})$, and $Me_3SiCHN_2$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data : monoclinic, space group $P2_1/n$, $a=10.1986(12)\;{\AA}$, $b=14.834(5)\;{\AA}$, $c=17.139\;{\AA}$, ${\beta}=92.24(2)^{\circ}$, Z=4, $V=2591.0(14)\;{\AA}^3$. The structure was solved by direct methods and refined by full-matrix leat-squares methods to give a model with a reliability factor R=0.053 for 5080 reflections.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3795-3799
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• 2013

The second-order rate constants ($k_N$) have been measured spectrophotometrically for nucleophilic substitution reactions of Y-substituted-phenyl 2-methylbenzoates (6a-e) with a series of cyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. Comparison of the $k_N$ values for the reactions of 4-nitrophenyl 2-methylbenzoate (6d) with those reported previously for the corresponding reactions of 4-nitrophenyl 2-methoxybenzoate (5) reveals that 6d is significantly less reactive than 5, indicating that modification of 2-MeO in the benzoyl moiety of 5 by 2-Me (i.e., $5{\rightarrow}6d$) causes a significant decrease in reactivity. This supports our previous report that aminolysis of 5 proceeds through a six-membered cyclic intermediate, which is highly stabilized through intramolecular H-bonding interactions. The Br${\o}$nsted-type plot for the reactions of 6d with a series of cyclic secondary amines is linear with ${\beta}_{nuc}=0.71$, which appears to be a lower limit of ${\beta}_{nuc}$ for a stepwise mechanism with breakdown of an intermediate ($T^{\pm}$) being rate-determining step (RDS). The Br${\o}$nsted-type plot for the reactions of 6a-e with piperidine is curved, i.e., the slope of Br${\o}$nsted-type plot (${\beta}_{lg}$) decreases from -1.05 to -0.41 as the leaving-group basicity decreases. The nonlinear Br${\o}$nsted-type plot has been taken as evidence for a stepwise mechanism with a change in RDS (e.g., from the $k_2$ step to the $k_1$ process as the leaving-group basicity decreases). Dissection of $k_N$ into the microscopic rate constants associated with the reactions of 6a-e with piperidine (e.g., $k_1$ and $k_2/k_{-1}$ ratio) also supports the proposed mechanism.

• Applied Biological Chemistry
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• v.49 no.4
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• pp.339-342
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• 2006

Canna generalis was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. from the EtOAc and n-BuOH fractions, four compounds were isolated through the repeated silica gel and ODS column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as $\beta$-sitosterol(1), linoleic acid methyl ester(2),1-O-oleoyl-2-O-linoleoyl-3-O-$\beta$-D-galactopyranosyl-sn-glycerol(3), and daucosterol(4). They were the first to be isolated from Canna generalis.

• Korean Journal of Pharmacognosy
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• v.49 no.2
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• pp.182-187
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• 2018

Many plant derived phytochemicals have been considered as the main therapeutic strategy against Alzheimer's disease (AD). AD is a progressive neurodegenerative disorder, and the most predominant cause of dementia in the elderly. Cholinergic deficit, senile plaque/${\beta}$-amyloid ($A{\beta}$) peptide deposition and oxidative stress have been identified as three main pathogenic pathways which contribute to the progression of AD. We screened many different plant species for their effective use in both modern and traditional system of medicines. In this study, we tested that MeOH extract of the stem bark of Hopea chinensis (Merr.) Hand.-Mazz. (HCM) affects on the processing of Amyloid precursor portein (APP) from the APPswe over-expressing Neuro2a cell line. We showed that HCM reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ in a dose dependent manner. We found that HCM increased over 1.5 folds of the secretion level of $sAPP{\alpha}$, a metabolite of ${\alpha}$-secretase. Furthermore, we found that HCM inhibited acetylcholinesterase activity in vitro. We suggest that the stem bark of Hopea chinensis may be a useful source to develop a therapeutics for AD.

• Korean Journal of Medicinal Crop Science
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• v.3 no.2
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• pp.91-95
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• 1995

From the whole plants of Oldenlandia diffusa ursolic acid together with sterols, ${\beta}-sitosterol$ and its $3-0-{\beta}-D-glucoside$ were isolated and characterized mainly by means of spectroscopic methods. Based on the present findings, it may be considered that this plant may contribute to be a rich source for ursolic acid.

• Korean Journal of Pharmacognosy
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• v.20 no.2
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• pp.76-82
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• 1989

Five known diosgenin glycosides have been isolated from the MeOH extract of Smilax china rhizomes and characterized as prosapogenin A of dioscin, dioscin, gracillin, methyl protogracillin, methyl protodioscin and its corresponding 22-hydroxy analog. This is the first isolation of the former four compounds from this plant. ${\beta}-Sitosterol\;glucoside$ was also isolated and identified.