• Title/Summary/Keyword: $IC_{50}$ values

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Cholinesterase Inhibitory Activities of Alkaloids from Corydalis Tuber

  • Hung, Tran Manh;Thuong, Phuong Thien;Nhan, Nguyen Trung;Mai, Nguyen Thi Thanh;Quan, Tran Le;Choi, Jae-Sue;Woo, Mi-Hee;Min, Byung-Sun;Bae, Ki-Hwan
    • Natural Product Sciences
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    • v.17 no.2
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    • pp.108-112
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    • 2011
  • Several isoquinoline alkaloids (1 - 18), which have basic chemical structures as protoberberine and aporphine skeletones, were evaluated for their inhibitory activities on AChE and BuChE. Among them, compounds 3, 4, 6, 8 and 12 showed the potent AchE activity with the $IC_{50}$ values ranging from $10.2{\pm}0.5\;{\mu}M$ to $24.5{\pm}1.6\;{\mu}M$, meanwhile, compound 14 - 17 exhibited strong inhibitory activity with $IC_{50}$ values from $2.1{\pm}0.2$ to $5.5{\pm}0.3\;{\mu}M$. Compounds 14 - 17 exhibited selective inhibition for AChE compared with BuChE. The isoquinoline alkaloid possesses aromatic methylenedioxy groups and quaternary nitrogen atoms are crucial for the anti-cholinesterase inhibitory activity.

Constituents and their DPPH Scavenging Activities from the Leaves of Alnus hirsuta (Spach) Rupr.

  • Dai, Yinghui;Thuong, Phuong Thien;Hung, Tran Manh;Jin, Wenyi;Cui, Zheng;Bae, Ki-Hwan
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.2
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    • pp.85-90
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    • 2005
  • Phytochemical study on the EtOAc fraction from a MeOH extract of the leaves of Alnus hirsuta Rupr. led to the isolation of nine compounds betulin (1), betulinic acid (2), hirsutanonol (3), hirsutenone (4), quercetin (5), avicularin (6), gallic acid (7), hyperin (8), and daucosterol (9). Among them, six compounds 1, 2, 57, and 9 are report from this plant for the first time. All isolated compounds were evaluated for their antioxidant activity using DPPH radical scavenging capacity and inhibition effect on mitochondrial lipid peroxidation. Six phenolic compounds 3-8 were found to have potent antioxidant activity. Of which, compounds 3, 4 and 5 showed significant free radical scavenging activity with the $IC_{50}$ values of $18.3\;{\pm}\;2.5,\;15.7\;{\pm}\;3.8\;and\;23.5\;{\pm}\;3.1\;{\mu}m$, respectively. In addition, the compounds 3-8 exhibited inhibition effect on the mitochondrial lipid peroxidation with the $IC_{50}$ values of $88.0\;{\pm}\;6.5,\;12.6\;{\pm}\;1.2,\;8.0 \;{\pm}\;1.1,\;58.5\;{\pm}\;4.3,\;173.6\;{\pm}\;15.2,\;and\;75.0\; {\pm}\; 6.7\;{\mu}m$, respectively.

The Constituents Isolated from Peucedanum japonicum Thunb. and their Cyclooxygenase (COX) Inhibitory Activity

  • Zheng, Mingshan;Jin, Wenyi;Son, Kun-Ho;Chang, Hyeun-Wook;Kim, Hyun-Pyo;Bae, Ki-Hwan;Kang, Sam-Sik
    • Korean Journal of Medicinal Crop Science
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    • v.13 no.2
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    • pp.75-79
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    • 2005
  • Five coumarins, psoralen (1), scopoletin (2), isoimperatorin (4), (+)-marmesin (5) and xanthotoxin (6), three chromones, cimifugin (3), hamaudol (7) and sec-O-glucosylhamaudol (10), one sterol, daucosterol (8) and one aliphatic alcohol, galactitol (9) were isolated from the root of Peucedanum japonicum. Their chemical structures were identified by the physicochemical and spectroscopic data by comparing literature values. Among them, compounds 9 and 10 were isolated for the first time from this plant. The anti-inflammatory effects of isolated compounds were examined on cyclooxygenase (COX), compounds 1, 2 and 7 showed inhibitory activity on COX-1 with $IC_{50}$ values of 0.88, 0.27 and 0.30 mM, respectively. In the test for COX-2 activity, only compound 7 showed significant inhibitory activity with the $IC_{50}$ value of 0.57 mM. The other compounds exhibited weak inhibitory or no inhibitory activity.

Anticancer and Antimicrobial Activities of 13(E)-labd-13-ene-8α,15-diol from Brachyglottis monroi

  • Kim, Jong-Im;Choi, Hwa-Jung;Lee, Jae-Sook
    • Journal of Applied Biological Chemistry
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    • v.56 no.1
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    • pp.49-51
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    • 2013
  • In a previous study, we reported that 13(E)-labd-13-ene-$8{\alpha}$,15-diol (13E) possesses antiviral and anticancer activities. In this study, the anticancer and antimicrobial activities of 13(E) were evaluated against 4 cancer cell lines and 6 bacteria. 13(E) showed inhibitory effect on a variety of cancer cell lines. The $IC_{50}$ values was 8.3-21.3 ${\mu}g/mL$. 13(E) was the most effective growth inhibitor of murine leukaemia cell lines P388, producing approximately 8.3 ${\mu}g/mL$ of $IC_{50}$ in the cytopathic effect (CPE) method. 13(E) also inhibited the growth of the gram-positive bacteria (Staphylococcus aureus, Bacillus cereus and Listeria monocytogenes) and gram-negative bacteria (Vibrio parahaemolyticus, Escherichia coli and Salmonella enteritidis) with a range of minimum inhibitory concentration (MIC) values from 0.092 to 0.598 mg/mL and gram-negative bacteria were more sensitive to the compound (MIC, 0.092 mg/mL).

Further Isolation of Antioxidative $(+)-1-Hydroxypinoresinol-1-O-{\beta}-D-glucoside$ from the Rhizome of Salvia miltiorrhiza that Acts on Peroxynitrite, Total ROS and 1,1-Diphenyl-2-picrylhydrazyl Radical

  • Kang, Hye-Sook;Chung, Hae-Young;Byun, Dae-Seok;Choi, Jae-Sue
    • Archives of Pharmacal Research
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    • v.26 no.1
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    • pp.24-27
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    • 2003
  • A furanofuranoid lignan glycoside, with radical scavenging on peroxynitrite, total reactive oxygen species (ROS) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical, was isolated from the rhizome of Salvia miltiorrhiza and characterized as (+)-1-hydroxypinoresinol-1-Ο-$\beta$-D-glucoside based on spectroscopic evidence. The compound exhibited peroxynitrite, total ROS and DPPH radical scavenging activities with $IC_{50}$ values of 3.23$\pm$0.04, 2.26$\pm$0.07 and 32.3$\pm$0.13 $\mu$M, respectively. Penicillamine, Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid) and L-ascorbic acid, acting as positive controls, showed radical scavenging activities with $IC_{50}$ values of 6.72$\pm$0.25, 1.43$\pm$0.04 and 11.4$\pm$0.07 $\mu$M, respectively.

Screening of In vitro DNA-binding Activity from the Crude Drugs (생약으로부터 In vitro DNA 결합활성의 검색)

  • Kim, Youn-Seol;Jeong, Sei-Joon;Shin, Hwa-Woo;Kim, Youn-Chul
    • YAKHAK HOEJI
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    • v.42 no.2
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    • pp.144-148
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    • 1998
  • One hundred and seventeen crude drugs were screened for DNA-binding activity in vitro. The DNA-methyl green assay is a useful biochemical screen for the detection or development of biologically active compounds which bind to DNA. This assay is based upon the fact that free methyl green undergoes rapid spontaneous molecular rearrangement to its colorless carbinol base so that the liberation of the dye from DNA by displacement can be followed spectrophotometrically as a decrease in absorbance at 65Onm. Seven methanolic extracts of crude drugs including Cinnamomi Cortex spissus, Coicis Semen, Coptidis Rhizoma, Perillae Semen, Plantaginis Semen, Polygalae Radix and Zanthoxyli Fructus showed less than 2,000${\mu}$g/ml as their $IC_{50}$ values. The active principles of Plantaginis Semen and Zanthoxyli Fructus were transferred into organic solvents, which showed the $IC_{50}$ values with 588 and 574${\mu}$g/ml, respectively. These fractions have been selected for isolation of biologically active constituents.

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Anti-cell Adhesive Effect of Phenylacetylshikonin Analogues Related to their Cytotoxicity in A549 Cells

  • Kim, Seon-Hee;Song, Gyu-Yong;Sok, Dai-Eun;Ahn, Byung-Zun
    • Archives of Pharmacal Research
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    • v.20 no.2
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    • pp.155-157
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    • 1997
  • An attempt to estabilish the relationship between anti-cell adhesive action of phenylacetylshikonin analogues and their cytotoxicity against A549 cells was done. In the one hour incubation with A549 cells,${\alpha}$-methoxyphenylacetyl-(9), ${\alpha}$-acetoxyphenylacetyl-(13), 3,4-methylenedioxyphenylacetyl-(15) and 4-(N,N-dimethylamino)-phenylacetylshikonin (17) analogues showed a high anti-cell adhesive activity $(IC_100; value, 4-8{\mu}g/ml)$, while halophenylacetyl- and dimethoxy- or trimethoxyphenylacetyl analogues expressed no activity at $40{\mu}g/ml$, indicating that the presence of a bulky group at $ C^I-{\alpha}$ and a polar group at C-4 of phenylacetyl moiety may be important. A similar structure activity relationship exists for the 48 hr cytotoxocity $(ED_{50})$ of phenylacetylshikonin analogues in A 549 cells, but not in either K562 or L1210 cells. Furthermore, the difference between $IC_{100}$ values for anti-cell adhesive activity and$ED_{50}$ values for cytotoxicity of potent compound in A549 cells was not so great (1.5 to 3 times). Based on these observations, it is proposed that the anti-cell adhesive action of phenylacetylshikonins might be responsible for their cytotoxicity in A549 cells.

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Structure and Activity of Angiotensin I Converting Enzyme Inhibitory Peptides Derived from Alaskan Pollack Skin

  • Byun, Hee-Guk;Kim, Se-Kwon
    • BMB Reports
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    • v.35 no.2
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    • pp.239-243
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    • 2002
  • Angiotensin I that converts the enzyme (ACE) inhibitory peptide, Gly-Pro-Leu, previously purified and identified from the Alaskan pollack skin gelatin hydrolysate, were synthesized. In addition, the peptides Gly-Leu-Pro, Leu-Gly-Pro, Leu-Pro-Gly, Pro-Gly-Leu, Pro-Leu-Gly, Gly-Pro, and Pro-Leu, which consisted of glycine, proline, and leucine, were synthesized by the solid-phase method. The $IC_{50}$ values of each tripeptide - namely Leu-Gly-Pro, Gly-Leu-Pro, Gly-Pro-Leu, Pro-Leu-Gly, Leu-Pro-Gly, and Pro-Gly-Leu - were 0.72, 1.62, 2.65, 4.74, 5.73, and $13.93{\mu}M$, respectively. The ACE inhibitory activity of these tripeptides was higher than that of dipeptides, such as Gly-Pro and Pro-Leu with $IC_{50}$ values of 252.6 and $337.3\;{\mu}M$, respectively. Among the tripeptides, Leu-Gly-Pro and Gly-Leu-Pro had higher inhibitory activity than Gly-Pro-Leu that was isolated from the Alaskan pollack skin gelatin hydrolysate. Among the different types of tripeptides that were examined, the highest ACE inhibitory activity was observed for Leu-Gly-Pro. It had the leucine residue at the N-terminal and proline residue at the C-terminal.

Effect of Caffeic Acid on the Production of Reactive Oxygen Species in Raw 264.7 Cells (Raw 264.7 세포에서 유해산소 생성에 미치는 Caffeic Acid의 영향)

  • Choi, Byung-Chul
    • YAKHAK HOEJI
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    • v.52 no.6
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    • pp.441-445
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    • 2008
  • To investigate effect of caffeic acid on the intracellular reactive oxygen species production, we used DHE for intracellular superoxide anion production, DCF for intracellular ${H_2}{O_2}$ production and DHR for intracellular hydroperoxide production in Raw 264.7 cells. DPPH assay showed that antioxidant activity of caffeic acid with 39.5 ${\mu}M$ of ${IC}_{50}$ values was similar to that of ascorbic acid with 41.3 ${\mu}M$ of ${IC}_{50}$ values. Caffeic acid dose-dependently inhibited silica-induced ${H_2}{O_2}$ and hydroperoxide production but did not affect superoxide anion production in Raw 264.7 cells, which suggest that antioxidant effect of caffeic acid acts on the post-step of superoxide anion. On the other hand, caffeic acid showed a potent antioxidant effect in $lCuSO_4$-induced lipid peroxidation. Furthermore, plasma superoxide dismutase activity (3.43${\pm}$0.23 U/ml) in 10 mg/kg caffeic acid-fed mice was significantly higher than that (2.32${\pm}$0.24 U/ml) of control. From the above results, it is referred that caffeic acid appears to have potent anti-oxidant activity in both cell system and in vivo system.

Mechanism Studies of Substituted Triazol-1-yl-pyrimidine Derivatives Inhibition on Mycobacterium tuberculosis Acetohydroxyacid Synthase

  • Chien, Pham Ngoc;Jung, In-Pil;Reddy, Katta Venugopal;Yoon, Moon-Young
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4074-4078
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    • 2012
  • The first step in the common pathway for the biosynthesis of branched chain amino acids is catalyzed by acetohydroxyacid synthase (AHAS). The AHAS is found in plants, fungi and bacteria. With an aim to identify new anti-tuberculosis drugs that inhibit branched chain amino acid biosynthesis, we screened a chemical library against Mycobacterium tuberculosis AHAS. The screening identified four compounds, AVS 2087, AVS 2093, AVS 2236, and AVS 2387 with $IC_{50}$ values of 0.28, 0.21, 3.88, and $0.25{\mu}M$, respectively. Moreover, these four compounds also showed strong inhibition against reconstituted AHAS with $IC_{50}$ values of 0.37, 0.26, 1.0, and $1.18{\mu}M$, respectively. The basic scaffold of the AVS group consists of 1-pyrimidin-2-yl-1H-[1,2,4]-triazole-3-sulfonamide. The most active compound, AVS 2387, showed the lowest total interaction energy -8.75 Kcal/mol and illustrates its binding mode by hydrogen bonding with $H_{\varepsilon}$ of Gln517 with the distance of $2.24{\AA}$.