• Korean Journal of Pharmacognosy
• /
• v.53 no.1
• /
• pp.16-20
• /
• 2022

Five ent-kaurane type diterpene glycosides were isolated from the aerial parts of Inula britannica var. chinensis Regel (Compositae) through repeated column chromatography. Their chemical structures were elucidated as 16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (1), 16β-hydroxy-17-acetoxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (2), 16β,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (3), 16α,17-dihydroxy-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (4) and 17-O-β-D-glucopyranosyl-16β-H-ent-kauran-19-oic acid-19-O-β-D-glucopyranoside (5), respectively, by spectroscopic analysis. Among these compounds, 1-4 were isolated for the first time from this plant.

• YAKHAK HOEJI
• /
• v.40 no.3
• /
• pp.262-272
• /
• 1996

The constituents of Sanguisorba hakusanensis leaves (Rosaceae), of which the roots have been used as an astringent, hemostatics and antiphlogistics, were studied phytoche mically. From water fraction of the MeOH extract, gallic acid 3-O-${\beta}$-D-(6'-O-galloyl)-glucopyranoside(I), quercetin-3-O-${\beta$-D-galactopyranoside(II), quercetin-3-O-${\alpha}$-L-arabinopyranoside(III) and $2{\alpha},\;3{\beta},\;19{\alpha}$, 23-tetrahydroxyurs-12-en-28-oic acid 28-O-${\beta}$-D-glucopyranoside(IV) were isolated by column chromatographic separation using Amberlite XAD-2, ODS-gel and Sephadex LH-20. The structure of these compounds were elucidated by spectroscopic parameters of $^1H$-NMR, $^{13}C$-NMR, $^1H-^1H$ COSY, $^{13}C-^1H$ COSY, EI-Mass, FAB-Mass, IR, UV and by comparison with authentic samples.

• YAKHAK HOEJI
• /
• v.40 no.2
• /
• pp.170-176
• /
• 1996

A chemical examination of the aerial parts of Euphorbia pekinensis $R_{UPRECHT}$. (Euphorbiaceae) has led to the isolation of seven hydrolyzable tannins and ten fl avonoid glycosides. The former ones have been identified as gallic acid, methylgallate, 3-O-galloyl shikimic acid, 1,3,4,6-tetra-O-galloyl-${\beta}-_D$-glucose, 1,2,3,4,6-penta-O-galloyl-${\beta}-_D$-glucose, corilagin, geraniin and the latter ones as isoquercitrin, quercitrin, astragalin, afzelin, prunin, rutin, kaempferol-3-O-rutinoside, quercetin-3-O-(2"-O-galloyl)-${\beta}-_D$-glucoside and quercetin-3-O-(2"-O-galloyl)-${\alpha}-_L$-rhamnoside on the basis of chemical and spectroscopic evidence.

• Korean Journal of Pharmacognosy
• /
• v.23 no.1
• /
• pp.9-13
• /
• 1992

From the leaves of Polygala japonica, kaempferol (1), astragalin (2), kaempferol $3-O-(6'-O-acetyl)-{\beta}-D-glucopyranoside$ (3) and kaempferol $3,7-di-O-{\beta}-D-glucopyranoside$ (4), have been isolated and characterized by chemical and spectral means.

• Natural Product Sciences
• /
• v.18 no.4
• /
• pp.273-278
• /
• 2012

Further phytochemical investigation on the whole plant of Thyrsanthera suborbicularis, collected in Cambodia, led to kaempferol (1), vitexin (2), apigenin-7-O-neohesperidoside (3), chrysoeriol-7-O-${\beta}$-D-glucopyranoside (4), isorhamnetin 3-O-rutinoside (5), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl-(13)-${\alpha}$-L-rhamnopyranosyl-(16)-${\beta}$-D-galactopyranoside (6), kaempferol-3-O-${\alpha}$-L-rhamnopyranosyl(12)-O-[${\alpha}$-L-rhamnopyranosyl (16)]-${\beta}$-D-glucopyranoside (7), kaempferol-3-O-[6"-O-(E)-p-coumaroyl]-${\beta}$-D-glucopyranoside (8), kaempferol-3-O-[6"-O-(E)-p-coumaroyl]-${\beta}$-D-galactopyranoside (9), and amentoflavone (10). All the structures were confirmed by the interpretation of NMR (1D and 2D) and MS data, and comparison with the published values. Of the isolated compounds 1 - 10, compounds 8 and 10 displayed the inhibitory activity against NO production in LPS-induced Raw 264.7 cells with $IC_{50}$ values, 3.56 and $15.73{\mu}M$, respectively.

• YAKHAK HOEJI
• /
• v.39 no.3
• /
• pp.289-296
• /
• 1995

For the investigation of medicinal resources the studies were carried out to evaluated the pharmaco-constituents in the Leaves of Parthenocissus tricuspidata(Vitaceae), of which leaves have been used in Korea as folk remedies for the treatments of arthritis, jaundice, toothache, neuralgia, and etc. From 1-butanol fraction of the MeOH extract, Compound I ($C_{21}H_{18}O_{13}$, Quercetin-3-O-$\beta$-D-glucuronopyranoside), Compound II ($C_{21}H_{20}O_{12}$, Quercetin-3-O-$\beta$-D-glucopyranoside) and Compound III ($C_{25}H_{28}O_{12}$, Quercetin-3-O-(6"-n-butyl)-$\beta$-D-glucuronopyranoside) were isolated by column chromatographic separation using Sephadex LH-20 and ODS gel. Their structures were elucidated through instrumental analyses, such as $^{1}H$-NMR, $^{13}C$-NMR, IR, UV, El-Mass, FAB-Mass and GC. Especially compound III was Flavonol glycoside and named parthenosin.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.16 no.12
• /
• pp.1071-1076
• /
• 2003

The nonlinear properties and their stability of ZPCCD- based varistors, which are composed of ZnO P $r_{6}$ $O_{ll}$ - CoO-C $r_2$ $O_3$-D $y_2$ $O_3$-based ceramics, were investigated in the D $y_2$ $O_3$ content range of 0.0∼2.0 mol%. The incorporation of D $y_2$ $O_3$ greatly affected the nonlinear properties and the best nonlinearity was obtained from 0.5 mol% D $y_2$ $O_3$ with nonlinear exponent of 66.6 and leakage current of 1.2 $\mu$A. Further addition of D $y_2$ $O_3$ deteriorated the nonlinear properties. In stability against DC accelerated aging stress state: 0.95 $V_{1mA}$/15$0^{\circ}C$/24 h, the 0.5 mol％ D $y_2$ $O_3$-doped varistor exhibited the highest stability, in which the variation rate of varistor voltage and nonlinear exponent are -1.9% and 10.5%, respectively. The remainder varistors resulted in thermal runaway due to low density of ceramics.s.s.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.8
• /
• pp.1174-1181
• /
• 2003

The flow around a circular cylinder was controlled by attaching O-rings to reduce drag force acting on the cylinder. Four experimental models were tested in this study; one smooth cylinder of diameter D (D=60mm) and three cylinders fitted with O-rings of diameters d=0.0167 D, 0.05D and 0.067 D with pitches of PPD=2D, 1D, 0.5D and 0.25D. The drag force, mean velocity and turbulence Intensity profiles in the near wake behind the cylinders were measured for Reynolds numbers based on the cylinder diameter in the range of Re$_{D}$=7.8$\times$10$^3$~1.2$\times$10$^{5}$ . At Re$_{D}$=1.2$\times$10$^{5}$ , the cylinder fitted with O-rings of d=0.0167D in a pitch interval of 0.25D shows the maximum drag reduction of about 5.4%, compared that with the smooth cylinder. The drag reduction effect of O-rings of d=0.067D is not so high. For O-ring circulars, as the Reynolds number increases, the peak location of turbulence intensity shifts downstream and the peak magnitude is decreased. Flow field around the cylinders was visualized using a smoke-wire technique to see the flow structure qualitatively. The size of vortices and vortex formation region formed behind the O-ring cylinders are smaller, compared with the smooth cylinder.der.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.7
• /
• pp.1315-1319
• /
• 2008

A trisaccharide, 6d-Altro-Hepp$\alpha$ (1$\rightarrow$3) GlcNAc$\beta$ (1$\rightarrow$3) Gal$\alpha$ (1$\rightarrow$$OCH_2CH_2N_3$, as an O-antigenic repeating unit of Campylobacter jejuni serotypes O:23 and O:36, was synthesized. Coupling of the 6d-altro-Hepp$\alpha$ (1$\rightarrow$3) GlcNAc$\beta$ (1$\rightarrow$SEt donor with Gal$\alpha$ (1${\rightarrow}OCH_2CH_2Cl$ acceptor in the presence of NIS-TfOH promoter afforded the trisaccharide having the $\beta$ (1$\rightarrow$3) Gal linkage. $\beta$ -Stereospecificity and the desired regioselectivity for the 3-OH Gal are obtained. Subsequent hydrogenation, acetylation, azide displacement, hydrazinolysis, Nacetylation, and finally deacetylation furnished the title trisaccharide hapten for further glycoconjugation.

• Korean Journal of Mineralogy and Petrology
• /
• v.34 no.3
• /
• pp.177-191
• /
• 2021

The Zhenzigou Pb-Zn deposit, one of the largest Pb-Zn deposit in the northeast of China, is located at the Qingchengzi mineral field in Jiao Liao Ji belt. The geology of this deposit consists of Archean granulite, Paleoproterozoinc migmatitic granite, Paleo-Mesoproterozoic sodic granite, Paleoproterozoic Liaohe group, Mesozoic diorite and monzoritic granite. The Zhenzigou deposit which is a strata bound SEDEX or SEDEX type deposit occurs as layer ore and vein ore in Langzishan formation and Dashiqiao formation of the Paleoproterozoic Liaohe group. Based on mineral petrography and paragenesis, dolomites from this deposit are classified three type (1. dolomite (D₀) as hostrock, 2. dolomite (D₁) in layer ore associated with white mica, quartz, K-feldspar, sphalerite, galena, pyrite, arsenopyrite from greenschist facies, 3. dolomite (D₂) in vein ore associated with quartz, apatite and pyrite from quartz vein). The structural formulars of dolomites are determined to be Ca_1.00-1.03Mg_0.94-0.98Fe_0.00-0.06As_0.00-0.01(CO₃)₂(D₀), Ca_0.97-1.16Mg_0.32-0.83Fe_0.10-0.50Mn_0.01-0.12Zn_0.00-0.01Pb_0.00-0.03As_0.00-0.01(CO₃)₂(D₁), Ca_1.00-1.01Mg_0.85-0.92Fe_0.06-0.11 Mn_0.01-0.03As_0.01(CO₃)₂(D₂), respectively. It means that dolomites from the Zhenzigou deposit have higher content of trace elements compared to the theoretical composition of dolomite. Feo and MnO contents of these dolomites (D₀, D₁ and D₂) contain 0.05-2.06 wt.%, 0.00-0.08 wt.% (D₀), 3.53-17.22 wt.%, 0.49-3.71 wt.% (D₁) and 2.32-3.91 wt.%, 0.43-0.95 wt.% (D₂), respectively. The dolomite (D₁) from layer ore has higher content of these trace elements (FeO, MnO, ZnO and PbO) than dolomite (D₀) from hostrock and dolomite (D₂) from quartz vein. Dolomites correspond to Ferroan dolomite (D₀ and D₂), and ankerite and Ferroan dolomite (D₁), respectively. Therefore, 1) dolomite (D₀) from hostrock is a Ferroan dolomite formed by marine evaporative lagoon environment in Paleoproterozoic Jiao Liao Ji basin. 2) Dolomite (D₁) from layer ore is a ankerite and Ferroan dolomite formed by hydrothermal metasomatism origined metamorphism (greenschist facies) associated with Paleoproterozoic intrusion. 3) Dolomte (D₂) from quartz vein is a Ferroan dolomite formed by hydrothermal fluid origined Mesozoic intrusion.