• Journal of the Korean Chemical Society
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• v.23 no.1
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• pp.46-51
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• 1979

Condensation of 3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-${\beta}$-D-glucopyranosyl bromide (2) with 1,2;3,4-di-O-isopropylidene-${\alpha}$-D-galactopyranose (3) in the presence of silver triflate and syn-collidine gave 1,2;3,4-di-O-isopropylidene-6-O-(3,4,6-tri-O-acetyl-2-deoxy-2-phthalimido-${\beta}$-D-glucopyranosyl)-${\alpha}$-D-galactopyranose (4) in $86{\%}$ yield. Cleavage of phthalimido group and de-O-acetylation with hydrazine, acetylation, and hydrolysis of isopropylidene and O-acetyl groups furnished 6-O-(2-acetamido-2-deoxy-${\beta}$-D-glucopyranosyl)-D-galactopyranose (1) with overall yield of $65.8{\%}$ starting from 3. Some other derivatives of 1 which have free hydroxyl groups at the specific position have also been prepared from 4. These compounds could be used as precursors for further glycosidation reactions.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.285-290
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• 2001

Bioequivalence of two acetyl-1-carnitine tablets, test product (Carnitile tablet: Hanmi Pharm. Co., Ltd.) and reference product (Nicetil $e^{R}$ tablet: Dong-A Pharm. Co., Ltd.), was evaluated according to the guide- lines of Korea Food and Drug Administration (KFDA). Twenty-six healthy volunteers were divided randomly into two groups and administered the drug orally at the dose of 500 mg as acetyl-1-carnitine in a 2$\times$2 crossover study. Blood samples were taken at predetermined time intervals for 12 hours and the plasma concentration of acetyl-1-carnitine was determined using HPLC by derivatization with p-bromophenacyl bromide. The pearmacokinetic parameters (AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$) were calculated and ANOVA was utilized for the statistical analysis of parameters. The apparent differences of these parameters between two drugs were less than 20% (i.e., 1.26,-5.08 and 8.59% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The powers (1-$\beta$) for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, and Tmax were over 0.9. Minimal detectable difference ($\Delta$) at $\alpha$=0.05, 1-$\beta$=0.8 were less than 20% (i.e.,7.31, 14.88 and 11.77% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The confidence intervals ($\delta$) for these parameters were also within $\pm$ 20% (i.e.,-3.03$\leq$$\delta$$\leq$5.54, -13.80$\leq$$\delta$$\leq$3.64 and 1.69$\leq$$\delta$$\leq$15.48 for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). These results satisfied the criteria of KFDA guideline for bioequivalence, indicating Carnitile bioequivalent to Nicetil $e^{R}$ .TEX>$^{R}$ .> R/ . R/ .

• YAKHAK HOEJI
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• v.27 no.2
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• pp.181-184
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• 1983

DMSO-oxalyl chloride at low temperature in methylene chloride reacted with isolated secondary hydroxyl groups in some monosaccharides to give alkoxysulfonium salts, convertible to carbonyls in high yields upon addition of triethylamine. And 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-allofuranose which is the key intermediate in the synthesis of 3-O-acetyl-5-O-benzoyl- 2-deoxy-2- fluoro-D-arabinofuranosyl bromide, was also obtained by oxidizing 1, 2:5, 6-di-O-isopropylidene-.alpha.- D-glucofuranose with the oxidizing reagent, followed by reduction with sodium borohydride.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1686-1694
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• 2019

Objective: Lignin plays a relevant role in the inhibition of cell wall (CW) structural carbohydrate degradation. Thus, obtaining accurate estimates of the lignin content in tropical plants is important in order to properly characterize the mechanism of lignin action on CW degradation. Comparing conflicting results between the different methods available for commercial use will bring insight on the subject. This way, providing data to better understand the relationship between lignin concentration and implications with tropical forage degradation. Methods: Five grass species, Brachiaria brizantha cv $Marand{\acute{u}}$, Brachiaria brizantha cv $Xara{\acute{e}}s$(MG-5), Panicum maximum cv Mombaça, Pennisetum purpureum cv Cameroon, and Pennisetum purpureum cv Napier, were harvested at five maturity stages. Acid detergent lignin (ADL), Klason lignin (KL), acetyl bromide lignin (ABL), and permanganate lignin (PerL) were measured on all species. Lignin concentration was correlated with in vitro degradability. Results: Highly significant effects for maturity, lignin method and their interaction on lignin content were observed. The ADL, KL and ABL methods had similar negative correlations with degradability. The PerL method failed to reliably estimate the degradability of tropical grasses, possibly due to interference of other substances potentially soluble in the $KMnO_4$ solution. Conclusion: ADL and KL methods use strong acid ($H_2SO_4$) and require determination of ash and N content in the lignin residues, therefore, increasing time and cost of analysis. The ABL method has no need for such corrections and is a fast and a convenient method for determination of total lignin content in plants, thus, it may be a good option for routine laboratory analysis.

• YAKHAK HOEJI
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• v.48 no.2
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• pp.117-121
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• 2004

Ranunculin, a potent cytotoxic component of P. koreana, was synthesized by reacting (s)-(-)-5-(hydroxymethyl)-2(5H)-furanone with 2,3,4,6-tetra-O-acetyl-$\alpha$-D-glucopyranosyl bromide and successive removal of the acetyl protecting group by 0.5 M HCl/MeOH. A new deacetylation process of the intermediate tetraacetylranunculin was deviced giving a yield of 83% of ranunculin. Protoanemonin, the cytotoxic structural moiety of ranunculin, was synthesized by dehydration of (s)-(-)-5-hydroxymethyl-2(5H)-furanone. Ranunculin showed a moderate cytototoxic activity against A-549 (ED$_{50}$=7.53 $\mu\textrm{g}$/$m\ell$), NIH3T (ED$_{50}$=13.6$\mu\textrm{g}$/$m\ell$), and SK-OV-3 (ED$_{50}$=17.5 $\mu\textrm{g}$/$m\ell$). Meanwhile, protoanemonin also exhibited moderate cytotoxicity against A-549 (ED$_{50}$=9.38 $\mu\textrm{g}$/$m\ell$), NIH3T (ED$_{50}$=13.8 $\mu\textrm{g}$/$m\ell$), and SK-OV-3 (ED$_{50}$=15.1 $\mu\textrm{g}$/$m\ell$). It was found that both of the synthetic products showed a potenter cytotoxicity against A-549.ainst A-549.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.545-553
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• 2021

Objectives: This study aimed to investigate the cytotoxicity of Nexus RMGIC, an indirect restorative cement, on cell survival rate and reactive oxygen species (ROS) production in periodontal stem cells (PDSCs). Methods: PDSCs were incubated with serially diluted Nexus RMGIC eluates with and without the addition of N-acetyl-cysteine (NAC). Cell survival was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The ROS generation was determined by measuring the fluorescence intensity for 2',7'-dichlorofluorescin diacetate. Results: Nexus RMGIC exposure decreased cell proliferation and cell survival rate in a dose-dependent manner (1:8, 1:4, 1:2, 1:1) in PDSCs. The cytotoxicity of Nexus RMGIC was inhibited by treatment with 10-mM NAC. In addition, the production of ROS was detected by immunofluorescence after PDSCs were exposed to Nexus RMGIC. However, ROS generation was significantly suppressed in the NAC pretreatment compared with the Nexus RMGIC group. Conclusions: Nexus RMGIC increased the cytotoxicity and ROS generation. ROS was involved in Nexus RMGIC-induced cell toxicity.

• Applied Chemistry for Engineering
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• v.2 no.3
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• pp.229-237
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• 1991

Vinylester was syntheszed in the presence of amine and metal catalysts, such as triethylamine(TEA), triethylbenzyl ammonium chloride (TEBAC), cetyltrimethyl ammonium bromide (CTMAB), chromium acety] acetate (CAA), and triphenylantimony (TPA). Apropriate use of amine and organometal catalysts were 1.7~2.2 % (Wt. %), 2.5~3.1 % (Wt %) of charged methacrylic acid (MAA) in respect of reactivity, gel-time, and storage stability. The Order of reactivity was TEA>TEBAC>CTMAB>CAA>TPA. Temperature independence of catalyst showed more large deviation above $110^{\circ}C$. Storage stability could be improved without delay of gel-time by adding TPA in 2.0 % (Wt %) of charged MAA after synthesis.

• YAKHAK HOEJI
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• v.40 no.2
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• pp.163-169
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• 1996

Glycosidation of 20(S)-protopanaxadiol obtained by the alkaline hydrolysis of total ginsenosides with 2,3,4,6-tetra-O-acetyl-${\alpha$-D-glucopyranosyl bromide in the presence of $CdCO_3$ in benzene-dioxane gave a mixture of acetylated monoglucosides and diglucosides in a total yield of 68%. Under the same condenstion condition, 20-dehydroxyglucosides were formed by dehydration of 12-O-glucosides. The structures of produced glycosides were elucidated as 3-O-${\beta$-D-glucopyranosyl-20(S)-protopanaxadiol, 12-O-${\beta$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},12{\beta}$-diol, 3,12-di-O-${\beta}$-D-glucopyranosyl-dammar-20(22), 24-dien-$3{\beta},\;12{\beta}$-diol, respectively.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.425-429
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• 1994

The genuine aglycone, 20(S)-protopanaxadiol, obtained from the leaves of Panax ginseng as a result of direct alkaline treatment was isolated and characterized by spectroscopic evidences. The study on the yield of genuine aglycone which is produced from the treatment of some kinds of alkali was carried out. $Ginsenoside-Rh_2$ was synthesized by conjugation of 2,3,4,6-tetra-O-acetyl-${\alpha}$-D-glucopyranosyl bromide to 20(S)-protopanaxadiol in the presence of silver carbonate and cadmium cabonate. The preparation of $ginsenoside-Rh_2$ by this method is a new one which the yield of this saponin can be improved in the mild condition.

• Journal of the Korean Wood Science and Technology
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• v.14 no.4
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• pp.14-20
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• 1986

These experiments were carried out to determine the ultraviolet absorption spectra of AcBr lignins(acetyl bromide lignin) from 10 hardwood species grown in Mt. Jiri. 1. There were 3 peak positions, at 249nm(max. peak), at 262-266nm(shallow min. peak) and at 270-280nm(lower max. peak). The Bj$\ddot{o}$rkman lignin and lignin sulfonatic acid spectra had shoulders, but the AcBr lignin didn't. 2. Average absorbances of the AcBr lignin at peak positions were 0.457${\pm}$0.0077 at 249nm, 0.297${\pm}$0.0029 at 262-266nm and 0.309${\pm}$0.0067 at 270-280nm. 3. Average absorptivities of the AcBr lignin at peak positions were 25.005${\pm}$0.3825 at 249nm, 16.264${\pm}$0.2347 at 262-266nm and 16.863${\pm}$0.3444 at 270-280nm. 4. AcBr lignin absorptivities in each species were as follows: 16.939${\pm}$0.3735 in Acer pseudo-sieboldianum var. koreanum, 17.411${\pm}$0.2937 in Carpinus laxiflora, 16.579${\pm}$0.4348 in Comus controversa, 16.385${\pm}$0.4140 in Fraxinus rhynchophylla, 16.287${\pm}$0.4156 in Meliosma myriantha, 16.492${\pm}$0.1432 in Platycarya strobilacea, 16.343${\pm}$0.3177 in Prunus sargentii, 17.549${\pm}$0.3253 in Sophora japanica, 18.400${\pm}$0.2925 in Stewartia koreana, 16.245${\pm}$0.4339 in Styrax obassia. 5. As the spectra of AcBr lignin from hardwood showed the unpromounced peak from 270nm to 280nm, it was supposed that thes hardwood lignins were the guaiacyl-syringyl copolymers.