• Bulletin of the Korean Chemical Society
• /
• v.32 no.12
• /
• pp.4352-4360
• /
• 2011

A four dimensional quantitative structure activity relationship analysis was applied to a series of 50 flavonoid inhibitors of $p56^{lck}$ protein tyrosine kinase by the molecular comparative electron topological method. It was found that the -log (IC50) values of the compounds were highly dependent on the topology, size and electrostatic character of the substituents at seven positions of the flavonoid scaffold in this study. Depending on the negative or positive charge of the groups correctly embedded in these substituents, three-dimensional bio-structure to increase or decrease -log (IC50) values in the training set of 39 compounds was predicted. The test set of 11 compounds was used to evaluate the predictivity of the model. To generate 4D-QSAR model, the defined function groups and pharmacophore used as topological descriptors in the calculation of activity were of sufficient statistical quality ($R^2$ = 0.72 and $Q^2$ = 0.69). Ligand docking approach by using Dock 6.0. These compounds include many flavonoid analogs, They were docked onto human families of p56lck PTKs retrieved from the Protein Data Bank, 1lkl.pdb.

• ALGAE
• /
• v.21 no.3
• /
• pp.343-348
• /
• 2006

This study was conducted to screen in vitro angiotensin - I converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts at 20°C and 70°C, respectively, prepared from twenty-six red algae obtained from the coast of Jeju Island in Korea. Among aqueous extracts at 20°C (20AE) from red algae Lomentaria catenata showed the strongest ACE inhibitory activity and Lithophyllum okamurae recorded the second highest activity. From MeOH extract at 20°C (20ME) Ahnfeltiopsis flabelliformis possessed the strongest ACE inhibitory activity. Remarkable activities from MeOH extracts at 70°C (70ME) were observed in Grateloupia filicina, Sinkoraena lancifolia and Grateloupia lanceolata. However, no significant activity was found in aqueous extracts at 70°C (70AE). The IC50 values, which are concentrations required to inhibit 50% activity of ACE, for ACE inhibitory activities of 20AE from Lithophyllum okamurae and L. catenata were 13.78 and 12.21 μg mL–1, respectively. The IC50 values of 20ME from A. flabelliformis and Laurencia okamurae were 13.84 and 106.15 μg mL–1. Those of the 70ME from Bonnemaisonia hamifera, Grateloupia filicina, Sinkoraena lancifolia, G. lanceolata, Gracilaria vermiculophylla and L. okamurae ranged from 25.82 to 124.69 μg mL–1.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.1
• /
• pp.80-83
• /
• 2012

The addition of NaBr to the fermentation medium of a marine isolate of the fungus Dothideomycete sp. resulted in induced production of two toluhydroquinone derivatives, 5-bromotoluhydroquinone (1) and 4-O-methyltoluhydroquinone (2), and two known compounds, toluhydroquinone (3) and gentisyl alcohol (4). The structures of 1 and 2 were assigned through the spectroscopic data analyses. Compounds 1-4 showed a potent antibacterial activity against the methicillin-resistant and multidrug-resistant Staphylococcus aureus (MRSA and MDRSA) with MIC (minimum inhibitory concentration) values of 6.2, 12.5, 6.2, and 12.5 ${\mu}g/ml$, respectively. Compounds 1-4 also exhibited a moderate radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 11.0, 17.0, 12.0, and 7.0 ${\mu}M$, respectively, which were more active than the positive control, L-ascorbic acid ($IC_{50}$, 20.0 ${\mu}M$).

• Biomolecules & Therapeutics
• /
• v.17 no.1
• /
• pp.86-91
• /
• 2009

In our ongoing search for biological components from the Korea endemic plants, the MeOH extract of Ailanthus altissima leaves (Simaroubaceae) showed cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin $D_2$ ($PGD_2$) and leukotriene $C_4$ ($LTC_4$) in mouse bone marrow-derived mast cells (BMMCs). In further study, eight compounds, squalene (1), ${\beta}$-sitosterol (2), scopoletin (3), quercetin (4), luteolin (5), astragalin (6), scopolin (7), and daucosterol (8) were isolated, the chemical structures were elucidated on the basis of physicochemical and spectroscopic data and by comparison with those of published literatures. Among the compounds, 2, 4, and 5 strongly inhibited both the COX-2-dependent PGD2 generation with $IC_{50}$ values of 2.6, 7.3 and 2.5 ${\mu}M$, respectively and the generation of $LTC_4$ in the 5-LOX dependent phase with $IC_{50}$ values of 2.0, 5.1 and 1.8 ${\mu}M$, respectively, which suggest that the anti-inflammatory activity of A. altissima might occur in part via the inhibition of both $PGD_2$ and $LTC_4$ generation by 2, 4 and 5.

• Natural Product Sciences
• /
• v.12 no.4
• /
• pp.210-213
• /
• 2006

A 4,5-dioxoaporphine type alkaloid, cepharadione B (1), a phenolic acid, protocatechuic acid (2), and flavonols, quercetin (3), afzelin (4), and quercitrin (5), were isolated from the EtOAc-soluble extract of the whole plants of Houttuynia cordata. All the isolates (1-5) were subjected to in vitro bioassays to evaluate advanced glycation end products (AGEs) formation and rat lens aldose reductase (RLAR) inhibitory activity. The three flavonols 3-5 exhibited a significant inhibitory activity on AGEs formation with $IC_{50}$ values of 66.9, 58.9, and $32.3{\mu}M$, respectively. While the two flavonol rhamnosides 4 and 5 showed a remarkable inhibitory activity against RLAR with $IC_{50}$ values of 0.81 and $0.16{\mu}M$, respectively.

• Natural Product Sciences
• /
• v.17 no.2
• /
• pp.108-112
• /
• 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.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.2
• /
• pp.85-90
• /
• 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.

• Korean Journal of Medicinal Crop Science
• /
• v.13 no.2
• /
• pp.75-79
• /
• 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.

• Journal of Applied Biological Chemistry
• /
• v.56 no.1
• /
• pp.49-51
• /
• 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).

• Archives of Pharmacal Research
• /
• v.26 no.1
• /
• pp.24-27
• /
• 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.