• Analytical Science and Technology
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• v.7 no.1
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• pp.41-52
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• 1994

The importance of separation comes from demands on study for exact effect of synthetic drugs and the reactivity of enantiomer in biological system. Racemization rate was measured under the influence of heat, acid, UV-light, enzyme(trypsin) and 6N-HCl at $105^{\circ}C$ on alanine, threonine, isoleucine, lecuine, aspartic acid, methionine, glutamic acid, tyrosine. The method for the identification of overlapped amino acids with GC was developed from the close study of fragmentation pattern with mass spectrometry. With cyclodextrin bonded phase by HPLC, the separation of dansyl amino acid was tested for compartison.

• BMB Reports
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• v.28 no.2
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• pp.155-161
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• 1995

A nicotinic acetylcholine receptor (nAchR) isolated from the electric tissues of Torpedo californica has been reconstituted into a vesicle comprising a bifunctional azo-ligand (Bae 1) compound, and a liposome containing phospholipids and cholesterol (1 : 1, w/w). The liposome-mediated reconstituted receptor showed a concentration-dependent response to cholinergic drugs in a lithium ion flux assay. This liposome-mediated reconstituted nAchR was immobilized onto an electrode using various synthetic polymers which were tested for their response to the cholinergic ligands. The immobilized nAchR not only exhibited a linear response to a wide range of cholinergic ligand concentrations but also retained an operational stability which lasted for longer than 6 days. Thus, this result provides a basis for application of the immobilized nAchR-based biosensor in detecting cholinergic ligands in vitro.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.946-950
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• 2015

Recently, it has become a struggle to treat tuberculosis with the current commercial antituberculosis drugs because of the increasing emergence of multidrug-resistant (MDR) tuberculosis and extensively drug-resistant (XDR) tuberculosis. We evaluated here the antimycobacterial activity of tamoxifen, known as a synthetic anti-estrogen, against eight drugsensitive or resistant strains of Mycobacterium tuberculosis (TB), and the active intracellular killing of tamoxifen on TB in macrophages. The results showed that tamoxifen had antituberculosis activity against drug-sensitive strains (MIC, 3.125-6.25 µg/ml) as well as drugresistant strains (MIC, 6.25 to 12.5 µg/ml). In addition, tamoxifen profoundly decreased the number of intracellular TB in macrophages in a dose-dependent manner.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.31-31
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• 2018

Benign prostatic hyperplasia (BPH), which is the most common disorder in elderly men, involves androgenic hormone imbalance with chronic inflammation that causes imbalance between cell apoptosis and cell proliferation. As the root cause of the BPH remains unclear and synthetic drugs for treatment of BPH have undesirable side effects, the development of effective alternative medicines has been considered. Chinese Skullcap has been considered natural remedy to treat pyrexia, micturition disorder and inflammation. Although skullcap has effective properties on various diseases, the effects and molecular mechanism of Skullcap on BPH are not fully understood. Therefore, in this study, we evaluated the efficacy of Chinese Skullcap root extract (SRE) in testosterone-induced BPH rats. Compared with the untreated group, the SRE treatment group suppressed pathological alterations, such as prostate growth and increase in serum dihydrotestosterone and $5{\alpha}$-reductase levels. Furthermore, SRE significantly decreased the expression of androgen receptor and proliferating cell nuclear antigen. SRE also restored Bax/Bcl-2 balance. These effect of SRE was more prevalent than commercial $5{\alpha}$-reductase inhibitor, finasteride. Taken together, we propose that SRE suppresses abnormal androgen events in prostate tissue and inhibits the development of BPH by targeting inflammation- and apoptosis-related markers. These finding strengthens that SRE could be used as plant-based $5{\alpha}$-reductase inhibitory alternative.

• The Korean Journal of Malacology
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• v.25 no.1
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• pp.15-22
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• 2009

Because it is known that bivalve hearts contain various modulatory systems activated by neuroendocrine substances, it was examined whether different classes of endogenous and synthetic drugs of neuroendocrinological importance can influence cardiac functions of the Pacific oyster Crassostrea gigas. Cholinergically active agents acetylcholine and carbachol increased heart rates while diminishing cardiac contractility. Adrenergically active substances norepinephrine (NE) and epinephrine (Epi) also induced heart rate increase and contractility decrease. An $\alpha_1$-adrenergic receptor-selective agonist phenyephrine (PE) failed to modulate either parameter. The Epi-induced heart rate increase and contractile depression were both blocked significantly by non-selective $\beta_1/\beta_2$-adrenergic antagonist propranolol. A $\beta_1$-selective antagonist atenolol prevented Epi-induced heart rate decrease but not the contractile depression, suggesting possible $\beta_2$ receptors for Epi-induced contractile depression. The three autacoids examined exerted discrete responses: histamine increased heart rate and depressed contraction; $\gamma$-amino-butyric acid increased both parameters; serotonin failed to change either parameter. The 5 piscine anesthetic agents examined, MS-222, benzocaine, quinaldine, urethane, pantocaine and pentobarbital, all failed to influence the cardiac function of oysters. Collectively, activities of neuroendocrinologically acting agents in mammals showed unexpected and distinct activities from those in mammalian cardiovascular systems. These results obtained from substances of different physiological functions can serve as a basis for understanding neuroendocrine control of the heart function in Pacific oyster.

• Biomaterials and Biomechanics in Bioengineering
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• v.5 no.1
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• pp.65-86
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• 2020

As conventional drug delivery system is being improved rapidly by target-based drug delivery system, finding suitable Drug Delivery System (DDS) for new drugs remains a challenge. Although there are many drug delivery vehicles in existence, a significant improvement is required to some DDS such as for local, implant-based treatments used for musculoskeletal infections. Many polymers have been considered for providing the improvement in DDS. Synthetic polymer, for example, has gained popularity for broad-spectrum physicochemical and mechanical properties. This article reviews the biomedical applications of Poly(TriMethylene Carbonate-co-Caprolactone) (PTMCC), which has attracted attention due to its biocompatibility, biodegradability and rubber-like properties. Its synthesis, physical properties, and degradation are also discussed here. Although it is relatively new in biomedical applications, it is readily usable for the fabrication of differing format of DDS of superior mechanical strength and degradation properties. The use of PTMCC is expected to increase in coming years as more is revealed about its potentials.

• Genomics & Informatics
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• v.16 no.3
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• pp.44-51
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• 2018

Fluoroquinolone (FQ) antibiotics are an important class of synthetic antibacterial agents. These are the most extensively used drugs for treating bacterial infections in the field of both human and veterinary medicine. Herein, the antibacterial and pharmacological properties of four fluoroquinolones: lomefloxacin, norfloxacin, ciprofloxacin, and ofloxacin have been studied. The objective of this study was to analyze the antibacterial characteristics of the different fluoroquinolones. Also, the pharmacological properties of the compounds including the Lipinski rule of five, absorption, distribution, metabolism, and excretion, LD50, drug likeliness, and toxicity were evaluated. We found that among all four FQ molecules, ofloxacin showed the highest antibacterial activity through in silico assays with a strong interaction (-38.52 kJ/mol) with the antibacterial target protein (topoisomerase-II DNA gyrase enzyme). The pharmacological and pharmacokinetic analysis also showed that the compounds ciprofloxacin, ofloxacin, lomefloxacin and norfloxacin have good pharmacological properties. Notably, ofloxacin was found to possess an IGC50 (concentration needed to inhibit 50% growth) value of $0.286{\mu}g/L$ against the Tetrahymena pyriformis protozoa. It also tested negative for the Ames toxicity test, showing its non-carcinogenic character.

• Biomolecules & Therapeutics
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• v.4 no.3
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• pp.280-284
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• 1996

Licorice has been widely used in combination with other herbs or synthetic drugs for various disorders. In an effort to study the effect of licorice roots (Glycyrrhizae Radix, GR) and glycyrrhizin on the hepatic glucuronidation, we have previously found that the pretreatment of GR or glycyrrhizin for 6 days resulted in a marked increase in the enzymatic activity of 3-methylcholanthrene (3-MC)-inducible hepatic UDP-glucuronosyltransferase (UGT) isozyme that has high affinity toward phenolic substrates (p-nitrophenol form, UGTIA) in Sprague-Dawley rats. As an approach to elucidate the mechanism for the enzyme activation by licorice in rat liver, we examined the levels of hepatocellular mRNAs for UGTIA upon the treatment of GR or glycyrrhizin. The hepatic mRNAs were extracted from Sprague-Dawley rats and Wistar rats after the treatment of the methanol extract of GR (1 g/kg, p.o.), glycyrrhizin (23 mg/kg, p.o.) for 6 days, or 3-MC (40 mg/kg, i.p.) for 3 days. Using the UGT1A1 CDNA as a probe, we found that the mRNAs for the enzyme were induced by 3-MC treatment while those were influenced neither by GR nor by glycyrrhizin in both strains of rats. These results indicate that the activation of rat liver UGTI A by licorice and glycyrrhizin was not due to the induction of mRNAs for the enzyme.

• YAKHAK HOEJI
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• v.59 no.6
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• pp.266-269
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• 2015

Coccidiosis is induced by Toxoplasma gondii and Eimeria tenella and novel anticoccidial drugs have been requested. In this study, the anticoccidial effect of 3-(4-methoxybenzylaminomethylene)-1,3-dihydroindole-2-one (5-108) on T. gondii and E. tenella was evaluated. Novel synthetic derivative 5-108 showed 1.44 fold higher relative selectivity compared to pyrimethamine against T. gondii in vitro assay. In chicken study, compound 5-108 significantly decreased the number of oocytes of E. tenella in feces, obtained from E. tenella-infected chickens, by $33{\pm}2.64%$ and $23{\pm}3.60%$ (P<0.001) at $7^{th}$ day and $9^{th}$ day p.i.. Conclusively, compound 5-108 was effective against T. gondii and E. tenella.

• Biomolecules & Therapeutics
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• v.2 no.2
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• pp.155-160
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• 1994

Human immunodeficiency virus type 1 (HIV-1) protease is essential for the replication of the virus and it is therefore an attractive target for antiviral drugs of HIV-1. Several dipeptide isosteres containing 2-isoxazoline or $\alpha$-hydroxy ketomethylene have been synthesized and their inhibitory effects on the HIV-1 protease examined. The enzymatically active HIV-1 protease was purified to homogeniety from E. coli transformed with a recombinant plasmid (pMAL-pro) containing the entire gene encoding the protease. The purified protease had the substrate specificity with Km value of 9.8$\mu$M when an undecapeptide His-Lys-Ala-Arg-Val-Leu-(p-nitro)Phe-Glu-Ala-Nle-Ser-amide was used as a substrate, and the products from the substrate after specific cleavage by HIV-1 protease were analyzed by HPLC. The synthetic compounds containing dipeptide isosteres showed specific inhibitory effects while a dipeptide isostere containing an isoxazoline ring inhibited the HIV-1 protease competitively with Ki value of 500 $\mu$M. Even if the inhibition effects of HIV-1 protease were not very high, these novel dipeptide isosteres can be used as key structural moieties for developing specific inhibitors of HIV-1 protease.