• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.264.1-264.1
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• 2003

In order to search for the anti-HIV agents from natural products, Eighty MeOH extracts of medicinal plants were applied to a syncytia formation inhibition assay which is based on the interaction between the HIV-1 envelope glycoprotein gp120/gp41 and the cellular membrane protein CD4 of T lymphocytes. Among them, Ailanthus altissima showed a potent virus-cell fusion inhibitory activity. (omitted)

• 대한바이러스학회지
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• 제29권4호
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• pp.235-245
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• 1999

HIV-1 Tat, a strong transactivator, is essential for the HIV-1 replication and AIDS progression. The Tat function is markedly inhibited by human p53 anti-oncogene. However, the detail mechanism has not yet been clearly revealed. In our previous report, we have addressed that p53 is unlikely to interact directly with HIV-1 Tat. In the consecutive experiments, Tat-phosphorylation was found to increase in proportional to the amounts of transfected p53. This work was initiated to identify the signaling factor that is involved in the p53-mediated Tat suppression. Several protein kinases were tested for the phosphorylation of Tat, and we found that PKR is likely to be involved in the p53-mediated Tat suppression. PKR was co-immunoprecipitated by anti-Tat antibody in the Tat-expressing Jurkat cell lysates only when the cells were transfected by p53, indicating that PKR-Tat interaction depends on the p53 activity. The interaction seems to result in PKR-mediated Tat-phosphorylation. Tat function was not blocked by p53 when co-transfected trasiently with antisense-PKR. We have generated PKR-knock out Jurkat cell clone. The PKR defective Jurkat cells didn't show the p53-mediated Tat suppression. These data indicate that p53-mediated Tat suppression is strongly associated with PKR. PKR-mediated Tat phosphorylation experiments are now under investigation by kinase assay and co-immunoprecipitation in the presence or absence of p53.

• Plant Resources
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• 제4권3호
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• pp.196-199
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• 2001

Medicinal plants were screened for the inhibitory effects on human immunodeficiency virus type 1 pretense. Of the extracts tested, the strong inhibitory effects were observed in the acetone extracts of the pericarp of Camellia japonica. Camelliatannin H from the pericarp of C. japonica showed a potent inhibitory activity on HIV-1 pretense. Effects of the extract and compound from leaves of Zanthoxylum piperitum on the enzyme activities were investigated in the liver of bromobenzene-treated rats. The methanol extract and protocatechuic acid isolated from Z. pipetitum reduced the activity of aniline hydroxylase that increased by bromobenzene, while did not affect the activities of aminopyrin N-demethylase and glutathione S-transferase. The extract and protocatechuic acid recovered significantly the activity of epoxide hydrolase decreased by bromobenzene.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 The 8th International Symposium
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• pp.68-73
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• 2001

Medicinal plants were screened for the inhibitory effects on human immunodeficiency virus type 1 pretense Of the extracts tested, the strong inhibitory effects were observed in the acetone extracts of the pericarp of Camellia japonica. Camelliatannin H from the pericarp of C. japonica showed a potent inhibitory activity on HIV- 1 pretense. Effects of the extract and compound from leaves of Zanthoxylum piperitum on the enzyme activities were investigated in the liver of bromobenzene-treated rats. The methanol extract and protocatechuic acid isolated from Z. piperitum reduced the activity of aniline hydroxylase that increased by bromobenzene, while did not affect the activities of aminopyrin N-demethylase and glutathione S-transferase The extract and protocatechuic acid recovered significantly the activity of epoxide hydrolase decreased by bromobenzene.

• Archives of Pharmacal Research
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• 제24권6호
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• pp.514-517
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• 2001

In order to find potent virus-cell fusion inhibitory components from Korean edible clams, thirteen prepared polysaccharides were introduced to syncytia formation inhibition assay, which is based on the interaction between the HIV-1 envelope protein gp 120/41 and the cellular membutane protein CD4 of T lymphocytes. Among them, Meretrix petechialis showed a potent viruscell fusion inhibitory activity. Fusion index (F1) and percent (%) fusion inhibition of the polysaccharide of this clam were $0.21{\pm}0.02$, and $67.52{\pm}4.09$ at 100781m1, respectively. It exhibited almost equivalent virus-cell fusion inhibitory activity to that of dextran sulfate which was used as a standard control.

• 대한바이러스학회지
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• 제28권1호
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• pp.39-52
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• 1998

HIV-1 tat, a strong transactivator, is essential for the HIV-1 replication and AIDS progression. The Tat function is markedly inhibited by human anti-oncogene p53. This work was initiated to identify the p53-associated inhibitory mechanism on tat-mediated transactivation. Inhibitory function of p53 was confirmed by co-transfection of tat-expressing Jurkat cells with LTR-CAT plasmid, or H3T1 cells (LTR-CAT integrated HeLa cells) with different ratio of pSV-tat/pCDNA-p53 plasmids. Results from the direct protein-protein interaction between soluble p53 and tat, and yeast two-hybrid experiments showed that the co-suppression mechanism is unlikely to be due to the direct interaction. CAT activity was not affected by tat in Jurkat cells which were transfected with p53-promoter-CAT or p53-enhancer-CAT, suggesting that the tat-mediated p53 suppression is not directly associated with p53-promoter. Finally, we have tested protein kinase activity in p53-tranfected Jurkat cells, which might phosphorylate HIV-1 tat, resulting in inhibition of tat function. Some of our data lead us to assume that the p53-mediated tat inhibition is likely to be associated with p53-associated, signaling-mediated phosphorylation of tat, resulting in the dysfunction of tat. This study is now under investigation.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.630-644
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• 2003

A human Cu, Zn-superoxide dismutase (Cu, Zn-SOD) was fused with a Tat PTD of HIV-1 to produce a novel anti-aging ingredient, Tat-SOD for cosmeceuticals. Test of stability and evaluation of transduction efficacy and enzymatic activity suggest Tat-SOD is an effective active ingredient for anti-aging treatment.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3348-3352
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• 2010

Novel 4'-ethyl-5'-norcarbocyclic adenosine phosphonic acid analogues were synthesized from propionaldehyde 5 through a de novo acyclic synthetic route using reiterative Grignard additions and ring-closing metathesis (RCM) as key reactions. The synthesized nucleoside phosphonic acids analogues 17, 18, 19, and 21 were subjected to antiviral screening against human immunodeficiency virus.

• Molecules and Cells
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• 제21권1호
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• pp.7-20
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• 2006

The major event in human immunodeficiency virus type 1 (HIV-1) infection is the death of many cells related to host immune response. The demise of these cells is normally explained by cell suicide mechanism, apoptosis. Interestingly, the decrease in the number of immune cells, such as non-CD4+ cells as well as CD4+ T cells, in HIV infection usually occurs in uninfected bystander cells, not in directly infected cells. It has, therefore, been suggested that several soluble factors, including viral protein R (Vpr), are released from the infected cells and induce the death of bystander cells. Some studies show that Vpr interacts directly with adenine nucleotide translocator (ANT) to induce mitochondrial membrane permeabilization (MMP). The MMP results in release of some apoptogenic factors such as cytochrome-c (cyt-c) and apoptosis-inducing factor (AIF). Vpr also has indirect effect on mitochondria through enhancing the level of caspase-9 transcription and suppressing nuclear factor-kappa B (NF-${\kappa}B$). The involvement of p53 in Vpr-induced apoptosis remains to be studied. On the other hand, low level of Vpr expression has anti-apoptotic effect, whereas it's high level of expression induces apoptosis. Extracellular Vpr also exhibits cytotoxicity to uninfected bystander cells through apoptotic or necrotic mechanism. The facts that Vpr has cytotoxic effect on both infected cells and bystander cells, and that it exhibits both proand anti-apoptotic activity may explain its role in viral survival and disease progression.

• 통합자연과학논문집
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• 제8권3호
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• pp.153-163
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• 2015

Racemic synthesis of novel 5',5'-difluoro-2'-methyl-apiose nucleoside phosphonic acid analogs was achieved as potent antiviral agents. Phosphonation was performed by direct displacement of triflate intermediate with diethyl (lithiodifluoromethyl) phosphonate to give the corresponding (${\alpha},{\alpha}$-difluoroalkyl) phosphonate. Condensation successfully proceeded from a glycosyl donor with persilylated bases to yield the nucleoside phosphonate analogs. Deprotection of diethyl phosphonates provided the target nucleoside analogs. An antiviral evaluation of the synthesized compounds against various viruses such as HIV, HSV-1, HSV-2 and HCMV revealed that the pyrimidine analogs (cytosine, uracil, and thymine) have weak anti-HIV or HCMV activity.