• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.170-173
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• 2000

The inhibitory effect of extracts from 15 edible plants on the protease of human immunodeficiency virus (HIV) type 1 was investigated. Protease activity was determined by incubating the extracts in a reaction mixture containing protease and substrate His-Lys-Ala-Arg-Val-Leu-(p-NO$_2$-Phe)-Glu-Ala-Nle-Ser-NH$_2$ to inhibit proteolytic cleavage. Of various plants tested, the leaves of Cedrela sinensis inhibited the HIV-1 protease by 42% at a concentration of 100$\mu\textrm{g}$/ml. A major flavonoid isolated from the leaves of C. sinensis, quercetin 3-O-$\alpha$-L-rhamnoside showed inhibitory activity of 19% at a concentration of 100$\mu$M.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.123-127
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• 2002

Ninety nine extracts from Korean plants were screened for their inhibitory activities on human immunodeficiency virus (HIV) type 1 pretense by an HPLC method. The pretense inhibitory activities were determined by incubating the extracts in reaction mixtures containing pretense and substrate (His-Lys-Ala-Arg-Val-Leu-(p-NO$_2$- Phe)-Glu-Ala-Nle-Ser-NH$_2$) to perform proteolytic cleavage reactions. Of the extracts tested, the water extracts of Viburnum awabuki (stem and leaves) and Distylium racemosum (leaves) had the highest pretense inhibitory activities at a concentration of 100ug/mL. Activity-guided fractionation, revealed that the n-butanol fraction of the V. awabuki extract and the ethyl acetate fraction from the D. racemosum extract had the greatest inhibitory activity on HIV-1 pretense.

• Natural Product Sciences
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• v.3 no.1
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• pp.1-7
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• 1997

Eucalyptus is a rich source of biologically active compounds. Among these, phloroglucinol compounds such as sideroxylonals, macrocarpals, euglobals, and robustadials are unique to Eucalyptus species. Sideroxylonal A is a very potent attachment-inhibitor. Macrocarpals show very strong antibacterial activity against gram positive bacteria. Macrocarpals also show HIV-RTase inhibitory activity. Euglobals are potent inhibitors of Epstein-Barr virus activation and are developed as skin and antitumor agents. They also show granulation inhibitory activity. In this review we aim to remove the existing confusion in literature on macrocarpals and discuss the biological activities and structure-activity relationships of phloroglucinol compounds.

• Bulletin of the Korean Chemical Society
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• v.21 no.12
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• pp.1207-1212
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• 2000

The free energy simulation technique is used to evaluate the relative binding affinity of a set of hydroxyethylene isostere inhibitors of the HIV-1 protease. The binding reactions and an alchemical mutation construct the thermodynamic cycle, which reduces the free energy difference of the binding interactions into that of the alchemical processes. In the alchemical process, a methyl group is mutated into a hydrogen atom. Albeit the change is a small perturbation to the inhibitor-protease complex, it results in 25 fold difference in the binding constants. The simulation reproduces the experimentally measured binding affinities within 2% of the free energy difference. The protonation state of the catalytic aspartic acid residues is also investigated through the free energy simulations.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1173-1179
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• 2009

Trypsin inhibitors and lectins are defense proteins produced by many organisms. From Chinese 'Large Black Soybeans', a 60 kDa lectin and a 20 Da trypsin inhibitor (TI) were isolated using chromatography on Q-Sepharose, Mono Q, and Superdex 75. The TI inhibited trypsin and chymotrypsin with an $IC_{50}$ of 5.7 and $5{\mu}M$, respectively. Trypsin inhibitory activity of the TI was stable from pH 3 to 13 and from 0 to $65^{\circ}C$. Hemagglutinating activity of the lectin was stable from pH 2 to 13 and from 0 to $65^{\circ}C$. The TI was inhibited by dithiothreitol, signifying the importance of disulfide bond. The TI and the lectin inhibited HIV-1 reverse transcriptase ($IC_{50}$=44 and $26{\mu}M$), and proliferation of breast cancer cells ($IC_{50}$=42 and $13.5{\mu}M$) and hepatoma cells ($IC_{50}$=96 and $175{\mu}M$). The hemagglutinating activity of the lectin was inhibited most potently by L-arabinose. Neither the lectin nor the TI displayed antifungal activity.

• YAKHAK HOEJI
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• v.53 no.2
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• pp.89-92
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• 2009

Dicaffeoyltartaric acid has a structural feature consisting of two caffeic acid units separated by tartaric acid linker and has been found to be a potent inhibitor of HIV-1 integrase and an antioxidant. In this study, bis(pyronyl)acrylic acid esters joined through a 5-membered ring as a linker were synthesized as the analogues of dicaffeoyltartaric acid.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2063-2069
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• 2011

We studied the interaction of 3,3',3'',3'''-ethylenetetrakis-4-hydroxycoumarin (EHC) with bovine serum albumin (BSA) in acetate buffer and phosphate buffer with different pH values by UV-vis absorption spectrometry and fluorescence spectrometry respectively. It was found that the pH values of the buffer solutions had an effect on the interaction process. In acetate buffer of pH 4.70, the carbonyl groups in EHC bound to the amino groups in BSA by means of hydrogen bond and van der Waals force, which made the extent of peptide chain in BSA changed. By contrast, in phosphate buffer of pH 7.40, hydrophobic force played a major role in the interaction between EHC and BSA, while the hydrogen bond and van der Waals force were also involved in the interaction. The results of spectrometry indicated that BSA could enhance the fluorescence intensity of EHC by forming a 1:1 EHC-BSA fluorescent complex through static mechanism at pH 4.70 and 7.40 respectively. Furthermore, EHC bound on site 1 in BSA.