• Bulletin of the Korean Chemical Society
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• 제33권5호
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• pp.1627-1637
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• 2012

The coupling reaction between 5-bromo-3-phenylbenzo[c]isoxazole and diphenylamine followed by further condensation with a mono-, di- or ter-acetyl aromatic compound in the presence of diphenyl phosphate at $145^{\circ}C$ gave a novel asymmetric diarylquinolines, oligoquinolines with diphenylamine endgroups, and a first generation quinoline dendrimer in 41-82% isolated yield. The electrochemical and photophysical properties of the oligoquinolines were characterized by cyclic voltammograms (CVs) and spectroscopy. All the quinolines emit bright sky blue light due to charge transfer from quinoline group to diphenly amine with very high quantum efficiency (> 90%). Organic light-emitting diodes (OLEDs) were fabricated using these quinolines as emitting materials. Among different device architectures explored, OLEDs with a structure of ITO/PEDOT (40 nm)/TAPC (15 nm)/D-A quinoline (40 nm)/TPBI (30 nm)/LiF (1 nm)/Al using TAPC as an electron blocking layer and TPBI as a hole blocking layer gave the best performance. A high external quantum efficiency in the range of 1.2-2.3% were achieved in all the quinolines with the best performance in BBQA(5). Our results indicate diarylamino-substituted oligoquinoline and dendrimer are promising materials for OLEDs applications.

• Biomolecules & Therapeutics
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• 제32권1호
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• pp.104-114
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• 2024

Licochalcone C (LCC; PubChem CID:9840805), a chalcone compound originating from the root of Glycyrrhiza inflata, has shown anticancer activity against skin cancer, esophageal squamous cell carcinoma, and oral squamous cell carcinoma. However, the therapeutic potential of LCC in treating colorectal cancer (CRC) and its underlying molecular mechanisms remain unclear. Chemotherapy for CRC is challenging because of the development of drug resistance. In this study, we examined the antiproliferative activity of LCC in human colorectal carcinoma HCT116 cells, oxaliplatin (Ox) sensitive and Ox-resistant HCT116 cells (HCT116-OxR). LCC significantly and selectively inhibited the growth of HCT116 and HCT116-OxR cells. An in vitro kinase assay showed that LCC inhibited the kinase activities of EGFR and AKT. Molecular docking simulations using AutoDock Vina indicated that LCC could be in ATP-binding pockets. Decreased phosphorylation of EGFR and AKT was observed in the LCC-treated cells. In addition, LCC induced cell cycle arrest by modulating the expression of cell cycle regulators p21, p27, cyclin B1, and cdc2. LCC treatment induced ROS generation in CRC cells, and the ROS induction was accompanied by the phosphorylation of JNK and p38 kinases. Moreover, LCC dysregulated mitochondrial membrane potential (MMP), and the disruption of MMP resulted in the release of cytochrome c into the cytoplasm and activation of caspases to execute apoptosis. Overall, LCC showed anticancer activity against both Ox-sensitive and Ox-resistant CRC cells by targeting EGFR and AKT, inducing ROS generation and disrupting MMP. Thus, LCC may be potential therapeutic agents for the treatment of Ox-resistant CRC cells.

• Archives of Pharmacal Research
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• 제29권10호
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• pp.874-878
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• 2006

Methyl gallate (MG) is a medicinal herbal product that is isolated from Paeonia lactiflora that inhibits cyclooxygenase-2 (COX-2) dependent phases of prostaglandin $D_2\;(PGD_2)$ generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with an $IC_{50}$ values of $17.0\;{\mu}M$. This compound also found inhibited the COX-2-dependent conversion of the exogenous arachidonic acid to $PGD_2$ in a dose-dependent manner with an $IC_{50}$ values of $190\;{\mu}M$, using a COX enzyme assay kit. However, at concentrations up to $80\;{\mu}M$, MG did not inhibit COX-2 protein expression in BMMC, indicating that MG inhibits COX-2 activity directly. Furthermore, MG consistently inhibited the production of leukotriene $C_4\;(LTC_4)$ in a dose dependent manner, with an $IC_{50}$ value of $5.3\;{\mu}M$. These results demonstrate that MG has a dual cyclooxygenase-2/5-lipoxygenase inhibitory activity, which might provide the basis for novel anti-inflammatory drugs.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.127-134
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• 2021

Neuroinflammation―a common pathological feature of neurodegenerative disorders such as Alzheimer's disease―is mediated by microglial activation. Thus, inhibiting microglial activation is vital for treating various neurological disorders. 7,3',4'-Trihydroxyisoflavone (THIF)―a secondary metabolite of the soybean compound daidzein―possesses antioxidant and anticancer properties. However, the effects of 7,3',4'-THIF on microglial activation have not been explored. In this study, antineuroinflammatory effects of 7,3',4'-THIF in lipopolysaccharide (LPS)-stimulated BV2 microglial cells were examined. 7,3',4'-THIF significantly suppressed the production of the proinflammatory mediators nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) as well as of the proinflammatory cytokine interleukin-6 (IL-6) in LPS-stimulated BV2 microglial cells. Moreover, 7,3',4'-THIF markedly inhibited reactive oxygen species (ROS) generation. Western blotting revealed that 7,3',4'-THIF diminished LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), glycogen synthase kinase-3β (GSK-3β), and nuclear factor kappa B (NF-κB). Overall, 7,3',4'-THIF exerts antineuroinflammatory effects against LPS-induced microglial activation by suppressing mitogen-activated protein kinase (MAPK) and NF-κB signaling, ultimately reducing proinflammatory responses. Therefore, these antineuroinflammatory effects of 7,3',4'-THIF suggest its potential as a therapeutic agent for neurodegenerative disorders.

• Journal of Applied Biological Chemistry
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• 제65권1호
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• pp.33-41
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• 2022

Esculetin (also known as 6, 7-dihydroxycoumarin) a type of coumarin, has been exhibited anti-inflammatory and anti-aging effects. Biorenovation is the microbe-mediated enhancement of biological efficacies and structurally diversified compounds relative to their substrate compounds. The production of different kinds of esculetin derivatives using Bacillus sp. JD3-7 and their effects on lipopolysaccharide (LPS)-triggered inflammatory response in RAW 26.7 cells were assessed. One of the biorenovation products, identified as esculetin 6-O-phosphate (ESP), at concentrations of 1.25, 2.5, and 5 μM inhibited the LPS-stimulated production of inflammation markers of nitric oxide synthase 2 and cyclooxygenase 2 as well as their respective enzymatic reaction products of nitric oxide and prostaglandin E2 in the order of increasing concentrations (1.25, 2.5, and 5 μM). Additionally, ESP treatment suppressed the LPS-stimulated secretion of pro-inflammatory cytokines of interleukin (IL)-1β, IL-6, and tumor necrosis factor- α. Furthermore, these anti-inflammatory effect of ESP was associated with the downregulation of mitogen-activated protein kinase signaling, that is, extracellular signal-regulated kinase, c-Jun NH2-terminal kinase, and p38 mitogen-activated protein kinase signaling pathways. This study would therefore provide interesting insights into the biorenovation-assisted generation of a novel anti-inflammatory compound. ESP may be used to develop treatments for inflammatory disorders.

• Biomolecules & Therapeutics
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• 제30권4호
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• pp.360-367
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• 2022

Tropomyosin receptor kinase A (TrkA) protein is a receptor tyrosine kinase encoded by the NTRK1 gene. TrkA signaling mediates the proliferation, differentiation, and survival of neurons and other cells following stimulation by its ligand, the nerve growth factor. Chromosomal rearrangements of the NTRK1 gene result in the generation of TrkA fusion protein, which is known to cause deregulation of TrkA signaling. Targeting TrkA activity represents a promising strategy for the treatment of cancers that harbor the TrkA fusion protein. In this study, we evaluated the TrkA-inhibitory activity of the benzoxazole compound KRC-108. KRC-108 inhibited TrkA activity in an in vitro kinase assay, and suppressed the growth of KM12C colon cancer cells harboring an NTRK1 gene fusion. KRC-108 treatment induced cell cycle arrest, apoptotic cell death, and autophagy. KRC-108 suppressed the phosphorylation of downstream signaling molecules of TrkA, including Akt, phospholipase Cγ, and ERK1/2. Furthermore, KRC-108 exhibited antitumor activity in vivo in a KM12C cell xenograft model. These results indicate that KRC-108 may be a promising therapeutic agent for Trk fusion-positive cancers.

• Applied Biological Chemistry
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• 제40권4호
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• pp.283-288
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• 1997

1% linoleic acid를 함유하는 수용성 완충용액과 LDL(low-density lipoprotein, 1 mg protein/ml)을 함유하는 수용성 완충용액 각각에 $H_2O_2$와 $FeCl_2$를 가하여 유발된 산화과정 중 한국산 홍삼 extract(red ginseng extract; RGE)에 대한 산화방지활성을 비교물질로 ${\alpha}-tocopherol$을 사용하여, HPLC를 이용한 MDA(malondialdehyde) 정량법과 fluorometry를 이용하여 측정 비교하였다. LDL(0.25 mg protein/ml)에서 생성된 conjugated diene도 spectrometry로 측정하였다. Linoleic acid를 기질로 사용한 경우, MDA 생성량으로 비교한 산화방지효과에 있어서 1000 ppm RGE의 첨가로 71.8%의 우수한 산화저해율이 나타났으며, 이때 비교물질로 사용한 100 ppm ${\alpha}-tocopherol$의 경우에는 76.1%이었다. LDL(1 mg/ml)을 기질로 사용하였을 경우에는 RGE 200 ppm 첨가시 가장 우수한 항산화효과가 나타났으며, 이때의 산화저해율은 25.2%이었고, 100 ppm ${\alpha}-tocopherol$의 경우는 21.2%이었다. 또한 LDL(0.25 mg protein/ml)을 기질로 사용하여 생성된 c-diene을 측정한 경우에도 50 ppm RGE의 첨가로 44.2% 저해효과가 입증되었다.

• 한국식생활문화학회지
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• 제35권6호
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• pp.597-604
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• 2020

This study examined the bioactive compound content and the antioxidant activities of bitter melon (Momordica charantia Linn.) leaves. The content of vitamin C, beta-carotene, and total carotenoids was 69.77, 45.68, and 65.08 mg/100 g, respectively. To investigate the antioxidant capacity, bitter melon leaves were extracted using various concentrations of ethanol (60, 80, or 100%). Highest content of total polyphenols (18.07 mg gallic acid equivalent/g) and flavonoids (4.53 mg cathechin equivalent/g) was found in the 100% ethanolic extract of the leaves (E100). Also, the E100 extract showed the highest levels of 2,2'azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and α-α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging activities. Reducing power was also the highest (39.21 mg Trolox equivalent/g) in E100 extract. The E100 extract effectively inhibited lipid peroxidation by 91.45% compared to the control group. Also, the E100 extract showed a cytoprotective effect against oxidative stress in HepG2 cells and decreased the generation of intracellular reactive oxygen species. These results suggest that bitter melon leaves could be regarded as a potential source of natural antioxidants.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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• pp.62-62
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• 2003

It is now convincing that free radical generation is involved in the pathophy siological mechanisms of ischemic stroke, particularly in ischemia-reperfusion injury. The present study, therefore, examined neuroprotective effect of aloesin isolated from Aloe vera, which was known to have antioxidative activity, in a rat model of transient focal cerebral ischemia. Transient focal cerebral ischemia was induced by occlusion of middle cerebral artery for 2 hr with a silicone-coated 4-0 nylon monofilament in male Sprague-Dawley rats under isoflurane anesthesia Aloesin (1, 3, 10, 30 and 50 mg/kg/injection) was administered intravenously 3 times at 0.5, 2 and 4 hr after onset of ischemia. Neurological score was measured 24 hr after onset of ischemia immediately before sacrifice. Seven serial coronal slices of the brain were stained with 2,3,5-triphenyltetrazolium chloride and infarct size was measured using a computerized image analyzer. Treatment with the close of 1 or 50 mg/kg did not significantly reduce infarct volume compared with the saline vehicle-treated control group. However, treatments with the closes of 3 and 10 mg/kg significantly reduced both infarct volume and edema by approximately 47% compared with the control group, producing remarkable behavioral recovery effect. Treatment with the close of 30 mg/kg also significantly reduced infarct volume to a lesser extent by approximately 33% compared with the control group, but produced similar degree of behavioral recovery effect. In addition, general pharmacological studies showed that aloesin was a quite safe compound. The results suggest that aloesin can serve as a lead chemical for the development of neuroprotective agents by providing neuroprotection against focal ischemic neuronal injury.

• 생명과학회지
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• 제24권8호
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• pp.873-879
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• 2014

소나무(Pinus densiflora)의 잎의 성분을 분리하여 항트롬빈 활성을 조사하였다. 잎은 70% ethanol로 3회 추출하였으며, 그 추출물은 순차적으로 chloroform과 n-buthanol로 분획하였다. n-buthanol 분획으로부터 얻은 수용성 분획을 MPLC와 HPLC에 의해 분리하였다. 분리한 compound를 $^1H-$과 $^{13}C-NMR$로 동정한 결과 2, 3-dihydro-7-hydroxyl-3-hydroxymethyl-2-(4'-hydroxyl-3-methoxyphenyl)-5-benzofuranpropanol-3-O-${\alpha}$-rhamnopyranoside(a neolignan glycoside)와 2, 3-dihyro-3-hydroxymethyl-7-methoxy-2-(4'-hydroxyphenyl-3'-methoxy)-5-benxofuran propanol 4'-O-${\alpha}$-rhamnopyranoside (icariside $E_4$)의 neolignan 구조임을 확인하였다. 트롬빈 저해활성은 분리된 neolignan glycoside와 icariside $E_4$을 작용하여 혈장안에서 응고시간으로 측정하였다. 그 결과, neolignan glycoside의 응고시간이 icariside $E_4$보다 4배 이상 지연하였다. 저해활성은 neolignan glycoside의 농도가 증가함에 따라 그 시간이 지연되는 것을 확인하였다. 더 나아가 지연기전을 확인하기 위해 thrombin과 순수한 fibrinogen를 반응하였다. 그 결과, 트롬빈과 순수한 피브리노겐의 작용에 의해 응고시간은 지연되었으며, 이는 neolignan glycoside가 피브린형성에 주요한 트롬빈의 활성을 직접 저해하는 것으로 사료된다.