• Title/Summary/Keyword: Activating reagent

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Regeneration of Pinusolide from Its 17-Nor-8-oxo Derivative

  • Han, Byung-Hoon;Song, Wan-Jin;No, Kwnag-Hyun
    • Biomolecules & Therapeutics
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    • v.5 no.2
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    • pp.107-109
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    • 1997
  • For metabolic study of pinusolide, a naturally occurring platelet activating factor antagonist, a synthetic method for preparation of radiolabeled pinusolide was studied. Pinusolide was first oxidized with $OsO_4/NaIO_4 $to 17-nor-8-oxo compound (2), which was subsequently converted to pinusolide by treatment with the Lombardo reagent $(Zn/CH_2Br_2/TiCI_4)$. The Wittily reaction was unsuccessful in the latter carbonyl methylenation of 2.

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A Study on The Synthesis of Camostat Mesylate Using Vilsmeier-Haack Reaction (Vilsmeier-Haack 반응을 이용한 Camostat Mesylate의 합성법 연구)

  • Kim, Dong Nyeon;Kim, Seok Chan
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.440-443
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    • 2022
  • A key step in the synthesis of camostat mesylate, which is most widely used as a treatment for chronic pancreatitis, was conducted. Camostat mesylate was synthesized through the esterification reaction of two intermediates, GBA (4-guanidinobenzoic acid hydrochloride) and DOHA [2-(dimethylamino)-2-oxoethyl-2-(4-hydroxyphenyl)acetate]. In order to overcome the problem raised due to the low yield and expensive reagents, a new economical synthesis method was developed that can produce camostat mesylate with a high yield of 80% by activating the acid functional group of GBA using the Vilsmeier-Haack reaction and coupling it with DOHA.

Preparation and Properties of Spherical BaMgAl10O17:Eu Phosphor by Multi-step Precipitation Method (다단 침전법에 의한 구형 BaMgAl10O17:Eu 형광체의 제조 및 특성)

  • Park, Jumg-Min;Jung, Ha-Kyun;Park, Hee-Dong;Park, Yoon-Chang
    • Korean Journal of Materials Research
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    • v.12 no.11
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    • pp.840-844
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    • 2002
  • A spherical $BaMgAl_{10}$ $O_{17}$ :Eu phosphor has been synthesized by a multi-step precipitation route. In order to successfully synthesize the phosphor with spherical shape, the hydrated-alumina particles should be controlled for spherical shape. In this process, the hydroxypropyl cellulose (HPC) was used as a dispersing reagent. This reagent plays an important role in that the particles were controlled to have the uniform size of sub-micron. The final product prepared by the multi-step precipitation method maintained spherical shape with uniform size of 0.4$\mu\textrm{m}$. It can be seen in X-ray diffraction patterns, formation of the single phase of $BaMgAl_{10}$ $O_{17}$ :Eu phosphor prepared by the multi-step precipitation method at $1350^{\circ}C$. Also, the emission spectra of spherical $BaMgAl_{O}$ $10_{17}$ :Eu phosphor in the present case was compared with those of commercially-available blue phosphor under VUV (Vacuum Ultra Violet) excitation. The luminescence process of the $BaMgAl_{10}$ $O_{17}$ :Eu phosphor is characterized by the $4f^{6}$$5d^1$longrightarrow4f$^{7}$ transition (blue) of the $Eu^{2+}$ ion acting as an activating center and the maximum luminescence intensity was obtained by reduction treatment at 145$0^{\circ}C$.

Chemical Modification of the Human Ether-a-go-go-related gene (HERG) $K^+$ Current by the Amino-Group Reagent Trinitrobenzene Sulfonic Acid

  • Jo Su-Hyun;Choi Se-Young;Yun Ji-Hyun;Koh Young-Sang;Ho Won-Kyung;Lee Chin-O.
    • Archives of Pharmacal Research
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    • v.29 no.4
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    • pp.310-317
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    • 2006
  • We investigated the effects of trinitrobenzene sulfonic acid (TNBS), an amino-group reagent, on the human ether-a-go-go-related gene (HERG) $K^+$ channels expressed in Xenopus oocytes. TNBS neutralizes the positively charged amino-groups of peptide N-terminal and lysine residues. External application of TNBS at 10 mM for 5 min irreversibly shifted the curves for currents at the end of the pulse and tail currents of HERG to a more negative potential and decreased the maximal amplitude of the $I_{tail}$ curve $(I_{tail,max})$. TNBS had little effect on either the activated current-voltage relationship or the reversal potential of HERG current, indicating that TNBS did not change ion selectivity properties. TNBS shifted the time constant curves of both activation and deactivation of the HERG current to a more hyperpolarized potential; TNBS's effect was greater on channel opening than channel closing. External $H^+$ is known to inhibit HERG current by shifting $V_{1/2}$ to the right and decreasing $I_{tail,max}$. TNBS enhanced the blockade of external $H^+$ by exaggerating the effect of $H^+$ on $I_{tail,max}$, not on $V_{1/2}$. Our data provide evidence for the presence of essential amino-groups that are associated with the normal functioning of the HERG channel and evidence that these groups modify the blocking effect of external $H^+$ on the current.

Practical Synthesis of N-Hydroxysuccinimide Using Lewis Acid Catalyst (Lewis Acid 촉매를 이용한 N-Hydroxysuccinimide의 실용적 합성법 연구)

  • Kim, Dong Nyeon;Kim, Seok Chan
    • Applied Chemistry for Engineering
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    • v.30 no.3
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    • pp.313-315
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    • 2019
  • A new synthetic method for N-hydroxysuccinimide (NHS), which is widely used in fine chemical and cosmetic industries, was developed. In a conventional synthesis, NHS is obtained by reacting $NH_2OH$ with succinic anhydride in a yield of about 70% using strong acid as a catalyst, which has an advantage of obtaining NHS relatively easily. However, it is expensive because of using a high cost succinic anhydride. In order to overcome this issue, we developed a new synthetic method for NHS with a moderate yield of 80% using a low cost succinic acid instead of succinic anhydride, alongside a stable Lewis acid catalyst, Zn acetate. As a result of the economic evaluation, it was confirmed that the cost reduction effect was about 15%.

Improved immune-enhancing activity of egg white protein ovotransferrin after enzyme hydrolysis

  • Lee, Jae Hoon;Kim, Hyeon Joong;Ahn, Dong Uk;Paik, Hyun-Dong
    • Journal of Animal Science and Technology
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    • v.63 no.5
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    • pp.1159-1168
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    • 2021
  • Ovotransferrin (OTF), an egg protein known as transferrin family protein, possess strong antimicrobial and antioxidant activity. This is because OTF has two iron binding sites, so it has a strong metal chelating ability. The present study aimed to evaluate the improved immune-enhancing activities of OTF hydrolysates produced using bromelain, pancreatin, and papain. The effects of OTF hydrolysates on the production and secretion of pro-inflammatory mediators in RAW 264.7 macrophages were confirmed. The production of nitric oxide (NO) was evaluated using Griess reagent and the expression of inducible nitric oxide synthase (iNOS) were evaluated using quantitative real-time polymerase chain reaction (PCR). And the production of pro-inflammatory cytokines (tumor necrosis factor [TNF]-α and interleukin [IL]-6) and the phagocytic activity of macrophages were evaluated using an ELISA assay and neutral red uptake assay, respectively. All OTF hydrolysates enhanced NO production by increasing iNOS mRNA expression. Treating RAW 264.7 macrophages with OTF hydrolysates increased the production of pro-inflammatory cytokines and the phagocytic activity. The production of NO and pro-inflammatory cytokines induced by OTF hydrolysates was inhibited by the addition of specific mitogen-activated protein kinase (MAPK) inhibitors. In conclusion, results indicated that all OTF hydrolysates activated RAW 264.7 macrophages by activating MAPK signaling pathway.

Relaxing Effects of Acanthopanacis Cortex through NO Production and PDE-5 Inhibition in Corpus Cavernosum (오가피의 NO 생성과 PDE-5 억제를 통한 음경해면체 이완효과)

  • Kim, Ho Hyun;Park, Sun Young
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.31 no.1
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    • pp.52-58
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    • 2017
  • This study was aimed to examine relaxing effects of Acanthopanacis cortex(AC) through nitric oxide(NO) production and phosphodiesterase type 5(PDE-5) inhibition in corpus cavernosum. In order to define the relaxation effects of AC extract, rabbit corpus cavernous tissues were prepared in $2{\times}2{\times}8mm$ sized strip. AC extract ($0.01-3.0mg/m{\ell}$) were treated in contracted strips induced by phenylephrine(PE) and $N{\omega}$-nitro-L-arginine (L-NNA) was treated before AC extract-treated. And calcium chloride($Ca^{2+}$) 1 mM was infused into precontracted strips after pretreatment of AC extract in $Ca^{2+}-free$ krebs-ringer solution. When AC extract was applied to human umbilical vein endothelial cell(HUVEC), cell viability was measured by MTT assay, and NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS, PDE-5 positive reaction were measured by histochemical and immunohistochemical process on mice corpus cavernosum. AC extract significantly affected relaxion of the cavernous strips, and the pretreatment of L-NNA inhibited AC extract-induced relaxation. Contraction induced by the addition of $Ca^{2+}$ was inhibited by treatment with the AC extract in $Ca^{2+}-free$ solution. In AC group, NO concentration, ratio of smooth muscle to collagen fibers, and eNOS positive reaction were increased, PDE-5 positive reaction was decreased compared to PE group. As a result of the above experiment, it was thought that AC extract inhibits the inflow of extracellular $Ca^{2+}$ by activating cGMP through the increase of eNOS / NO and the decrease of PDE-5 which inhibits cGMP activity, in the corpus cavernosum.

Cell proliferation and migration mechanism of caffeoylserotonin and serotonin via serotonin 2B receptor in human keratinocyte HaCaT cells

  • Kim, Hye-Eun;Cho, Hyejoung;Ishihara, Atsushi;Kim, Byungkuk;Kim, Okjoon
    • BMB Reports
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    • v.51 no.4
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    • pp.188-193
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    • 2018
  • Caffeoylserotonin (CaS), one derivative of serotonin (5-HT), is a secondary metabolite produced in pepper fruits with strong antioxidant activities. In this study, we investigated the effect of CaS on proliferation and migration of human keratinocyte HaCaT cells compared to that of 5-HT. CaS enhanced keratinocyte proliferation even under serum deficient condition. This effect of CaS was mediated by serotonin 2B receptor (5-HT2BR) related to the cell proliferation effect of 5-HT. We also confirmed that both CaS and 5-HT induced G1 progression via 5-HT2BR/ERK pathway in HaCaT cells. However, Akt pathway was additionally involved in upregulated expression levels of cyclin D1 and cyclin E induced by CaS by activating 5-HT2BR. Moreover, CaS and 5-HT induced cell migration in HaCaT cells via 5-HT2BR. However, 5-HT regulated cell migration only through ERK/AP-1/MMP9 pathway while additional Akt/NF-${\kappa}B$/MMP9 pathway was involved in the cell migration effect of CaS. These results suggest that CaS can enhance keratinocyte proliferation and migration. It might have potential as a reagent beneficial for wound closing and cell regeneration.

The Endothelium-Dependent Vasorelaxation Effect of Cynomorii Herba (쇄양(鎖陽)의 내피세포 의존성 혈관이완효과)

  • Park, Sun-Young
    • The Korea Journal of Herbology
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    • v.30 no.6
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    • pp.25-32
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    • 2015
  • Objectives : The purpose of this study was to investigate the endothelium-dependent vasorelaxation effect of Cynomorii Herba(CH) extract on contracted rabbit carotid artery.Methods : To clarify the vasorelaxation effect of CH extract, arterial strips with intact was used, to endothelium -dependent vasorelaxation effect of CH extract, arterial strips damaged endothelium was used for experiment using organ bath. Arterial strips was contracted with phenylephrine(PE) before treated with CH extract(0.01, 0.03 and 0.1 ㎎/㎖). To study mechanisms of CH-induced vasorelaxation effect, CH extract infused into arterial rings after treatment by indomethacin(IM), tetraethylammonium chloride(TEA), Nω-nitro-L-arginine (L-NNA), methylene blue(MB) for comparing with non-treated. And calcium chloride(Ca2+) 1 mM was treated into precontracted arterial ring induced by PE after treatment of CH extract in Ca2+-free krebs solution. Cytotoxic activity of CH extract on human umbilical vein endothelial cell(HUVEC) was measured by MTT assay, and nitric oxide(NO) concentration was measured by Griess reagent.Results : PE-induced arterial strips was significantly relaxed, but the damaged endothelium arterial ring wasn't relaxed by CH extract. Pretreatment of IM, TEA didn't inhibit the vasorelaxation of CH extract, but pretreatment of L-NNA, MB inhibited the vasorelaxation of CH extract. Pretreatment of CH extract reduced the increase of contraction by influx of extracellular Ca2+ in contracted arterial ring induced by PE, CH extract increased nitric oxide concentration on HUVEC significantly.Conclusions : This study shows that CH extract have the vasorelaxation effect by blocking the influx of extracellular Ca2+ through the activating NO-cGMP system.

Immune enhancement effect of Rubus coreanus Miquel (RC) (30% EtOH extract) in RAW264.7 cells (RAW264.7 세포주를 통한 복분자 30% 에탄올 추출물의 면역기능 활성증진효과 검토)

  • Cho, Jae-Kyung;Choi, Han-Seok;Kim, Min-Su;Kim, Young-Gook;Kim, Chi-Hong;Shin, Yong-Cheol;Ko, Seong-Gyu
    • Journal of Society of Preventive Korean Medicine
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    • v.16 no.3
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    • pp.155-165
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    • 2012
  • Objective : The object of this study is to confirm the immune enhancement effect of Rubus coreanus Miquel (RC) (30% EtOH extract) on RAW264.7 mouse macrophage cell line. Methods : RAW264.7 cells were treated with $10-500{\mu}g/mL$ RC for 24 hours. Cell viability was then measured using WST assays. Levels of intracellular NO and ROS were measured by Griess reagent and DCFH-DA staining respectively. Levels of iNOS and COX-2 mRNA was determined by RT-PCR. Secretion levels of IL-$1{\beta}$ and IL-6 cytokines were evaluated by sandwich ELISA assay. Western blot analysis was performed to measure the levels of intracellular molecules related to MAPKs pathways. Results : RC suppressed the growth of RAW264.7 cells. RC increased the production of NO and ROS. RC increased the mRNA and protein levels of COX-2 and iNOS. RC augmented the levels of secreted IL-$1{\beta}$ and IL-6 cytokines. RC increased MAPKs phosphorylation. Conclusion : In summary, our result shows that RC has inflammatory effect increasing the levels of NO, ROS and secreted cytokines and activating MAPKs. Hence, RC seems to have an immune enhancement effect.