• Journal of Ginseng Research
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• v.13 no.1
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• pp.37-41
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• 1989

Reactive metabolites generated by benzo(a)pyrene(BP) monooxygenase(AHH) interact with nucleophiles in DNA and cause mutation and carcinogenesis. We studied the effect of Panax ginseng C.A. Meyer, which induce epoxide hydratase(EH) activity without concomitant induction of AHH activity, on the binding of BP metabolites to DNA in uitro in Sprague Dawley rats. DNA-BP metabolite adducts can be resolved into at least five distinct peaks by elution of a Sephadex LH-20 column with a water methanol gradieNt. These peaks are arbitrarily designated A(most polar) through I(least polar). Of the 5 peaks tentatively assigned to 7,8 biol-9,10-oxide(A),7,8·oxide(B),4,5-oxide(C), and further metabolites of 9-OH-BP(D & E), peaks A, C, D, and I were reduced to 70, 85, 80, and 30% of controls, respectively, and there was no significant change in peak B. In connection with this DNA binding study, BP metabolizing enzymes including AHH, EH, demethylase(DM) activity and cyt. P-450 contents were also investigated in order to compare the BP treated control with ginseng and BP treated test groups. The results showed that the EH activity was increased by 139% over the BP control, the Cyt. P-450 content was increased by 180% over the control value, and DM and AHH activities were also increased to some degree for the BP test group, but there was no significant effect of the ginseng treatment.

• Toxicological Research
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• v.15 no.1
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• pp.95-101
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• 1999

Cytochrome P450 (CYP) 3A4 metabolizes aflatoxin B1 (AFB1) to AFB1-exo-8,9-epoxide (8,9-epoxidation) and aflatoxin Q1 (AFQ1; 3$\alpha$-hydroxylation) simultaneously. We investigated whether each metabolite was formed via its own binding site of CAP3A4 active site. Kinetics of the formation of the two metabolites were sigmoidal and consistent with the kinetics of substrate activation. The HIll model predicted that two substrate binding wites are involved in the oxidationof AFB1 by CYP3A4. Dehydronifedipine, a metabolite of nifedipine generated by CYP3A4, inhibited the formation of AFQ1 without any inhibition in the formation of AFB1-exo-8,9-epoxidation. Dehydronifedipine was found to act as a reversible competitive inhibitor against 3$\alpha$-hydroxylation of AFB1. Vmax and S0.5 of the 8,9-epoxidation were not changed in the presence of 0, 50, or 100 $\mu\textrm{M}$ dehydronifedipine. S0.5 of 3$\alpha$-hydroxylation was increased from 58$\pm$4 $\mu\textrm{M}$ to 111$\pm$8 $\mu\textrm{M}$ in the presence of 100 $\mu\textrm{M}$ nifedipine whereas Vmax was not changed. These results suggest that there exist two independent binding sites in the active site of CAP3A4 . One binding site is responsible for AFB1-exo-8,9-epoxidation and the other is involved in 3$\alpha$-hydroxylation of AFB1. Dehydronifedipine might selectively bind to the site which is responsible for the formation of AFQ1 in the active site of CYP3A4.

• YAKHAK HOEJI
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• v.36 no.2
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• pp.188-190
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• 1992

Two clones of monconal antibodies(Co-1 and Co-2) against BSA-benzoylecgonine(BSABE) were produced. Both monoclonal antibodies showed high binding affinity to BSA-BE. Observing from ELISA inhibition assay, Co-1 reacted only weakly with soluble benzoylecgonine, while Co-2 showed considerable reactivity with soluble benzoylecgonine.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.96-104
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• 2019

Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

• Journal of Pharmaceutical Investigation
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• v.15 no.1
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• pp.1-7
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• 1985

Previous studies show that the free (unbound) fraction of disopyramide in human serum is drug concentration dependent~ at corresponding serum disopyramide concentrations that are achieved clinically. $^1^{\sim}^3^)\;Moreover$, disopyramide free fraction values vary several fold at any given drug concentration in human serum and tend to decrease as serum cocentrations of alpha-I-acid glycoprotein(AAG) incrase.$^4^)$ A recent $study^5^)$ demonstrates that the free fraction of disopyramide inhuman serum increases almost 2-fold following the addition of $14.4{\mu}M/L$ mono-N-dealkyldisopyramide. These studies and others. $^6^),\;^7^)$ prompted the present investigation to characterize the protein binding of disopyramide in human serum and solutions of AAG in the presence of mono-N-dealkyldisopyramide (a major metabolite of, disopyramide) and to determine the utility of using commercially available alpha-I-acid glycoprotein for drug protein binding displacement studies. Because many basic and acidic compounds are known to bind to alpha-I-acid $glycoprotein^8^)$ the present study. was performed to determine whteher commercially available AAG would provide a convenient protein source for such binding studies.

• Toxicological Research
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• v.16 no.3
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• pp.221-227
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• 2000

A 6-sulfooxymethylbenzo[a]pyrene (SMBP), the ultimate metabolite of methyl-substituted benzo[a]pyrene (BP), has been found to be carcinogenic in mice. These properties may be attributable to its strong reactivity with cellular macromolecules such as DNA. However, serum and its major constituent albumin attenuated significantly the cytotoxicity and mutagenicity of 5MBP in bacterial and mammalian cell systems. This inhibitory activity of serum against 5MBP-induced cytotoxicity and mutagenicity in Chinese hamster V79 cells appears to be caused by the reduced macromolecular adducts such as DNA and proteins, but serum failed to reduce 5MBP binding to naked calf thymus DNA. A number of proteins in the serum could act as nucleophiles that are able to intercept reactive chemicals through covalent binding. Albumin present in the plasma seems to be one of major components responsible for direct binding with 5MBp, thereby reducing its reactivity to genetic materials. We here determined which fraction is preferential for 5MBP binding through fractionation of 5MBP-treated serum with ammonium sulfate. The albumin-containing fraction had slightly more affinity for 5MBP than the immunoglobulin-containing fraction. Our results indicate that the covalent modification of plasma proteins may reduce 5MBP-induced damage.

• Journal of Ginseng Research
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• v.13 no.1
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• pp.42-48
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• 1989

The binding of bay region diol-epoxides of polycyclic aromatic hydrocarbons (PAHs) to target tissue DNA is thought to be essential for the initiation of cancer by these compounds. In this study we investigated the effect of polyacetylenes such as panaxynol and panaxydol on the formation of benzo(a)pyreno (BP)-metabolite-DNA adduct in the liver of ICR mice. Treatment of mice by i.p. administration of polyacetylenes produced a marked reduction in BP metabolite binding to DNA in vitro. Following i.v. administration of (3H)BP(300, ${\mu}$Ci/21 nmoles/0.1 nt DMSO) to mice, radioactivity was detected in the DNA of the liver in vivo. The result of tentative identification of the 4 peaks between the two standard markers for high pressure liquid chromatography showed that the peaks. I, II, III, and IV were BP-phenol oxide-DNA adduct (or BP-diol-epoxide-dCyt. adduct), (-) BP$.$diolepoxide I:dGuO adduct, (+) BP-diol-epoxide I: dGuo adduct, and BP-diol-epoxide II:dGuO adduct, respectively. The minor adduct, (-) BP-diol epoxide I: dGuo was reduced to 6971 of the amount of the control, while the major adduct, (+) BP-diolepoxide I: dGuO(peak II) which was produced from (-) BP-7, 8-diol was reduced to 78% of that of the control. The amount of the minor adduct, BP-diol-epoxide II:dGuo adduct(peak IV) which formed from (+) BP-7, 8-diol was 58% of the control. These results show that the panaxydol is more related to inhibition of the formation of the minor ad- ducts than of the major adducts, which were generally produced from ($\pm$) BP-7, 8-dihydro-dials.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.186.2-186.2
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• 2003

PPARs (peroxisome proliferator activated receptors) are member of nuclear hormone receptors superfamily. Activations of PPARs upon binding with ligands modulate glucose metabolite, differentiation of adipocyte, inflammation response, and so on. Thiazolidinedione analog is one of the potential antidiabetic drug that binds and activates PPAR selectively and enhances insulin sensitivity. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, we have synthesized tetrahydroquinoline and para-substituted benzene-linked thiazolidinedione analogs by coupling reaction of the hydrophobic segments with hydroxybenzylthiazolidinedione.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1636-1642
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• 2016

Phenalamide is a bioactive secondary metabolite produced by Myxococcus stipitatus. We identified a 56 kb phenalamide biosynthetic gene cluster from M. stipitatus DSM 14675 by genomic sequence analysis and mutational analysis. The cluster is comprised of 12 genes (MYSTI_04318- MYSTI_04329) encoding three pyruvate dehydrogenase subunits, eight polyketide synthase modules, a non-ribosomal peptide synthase module, a hypothetical protein, and a putative flavin adenine dinucleotide-binding protein. Disruption of the MYSTI_04324 or MYSTI_04325 genes by plasmid insertion resulted in a defect in phenalamide production. The organization of the phenalamide biosynthetic modules encoded by the fifth to tenth genes (MYSTI_04320-MYSTI_04325) was very similar to that of the myxalamid biosynthetic gene cluster from Stigmatella aurantiaca Sg a15, as expected from similar backbone structures of the two substances. However, the loading module and the first extension module of the phenalamide synthase encoded by the first to fourth genes (MYSTI_04326-MYSTI_04329) were found only in the phenalamide biosynthetic gene cluster from M. stipitatus DSM 14675.

• Natural Product Sciences
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• v.21 no.4
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• pp.282-288
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• 2015

Viriditoxin is a fungal metabolite isolated from Paecilomyces variotii, which was derived from the giant jellyfish Nemopilema nomurai. Viriditoxin was reported to inhibit polymerization of FtsZ, which is a key protein for bacterial cell division and a structural homologue of eukaryotic tubulin. Both tubulin and FtsZ contain a GTP-binding domain, have GTPase activity, assemble into protofilaments, two-dimensional sheets, and protofilament rings, and share substantial structural identities. Accordingly, we hypothesized that viriditoxin may inhibit eukaryotic cell division by inhibiting tubulin polymerization as in the case of bacterial FtsZ inhibition. Docking simulation of viriditoxin to ${\beta}-tubulin$ indicated that it binds to the paclitaxel-binding domain and makes hydrogen bonds with Thr276 and Gly370 in the same manner as paclitaxel. Viriditoxin suppressed growth of A549 human lung cancer cells, and inhibited cell division with G2/M cell cycle arrest, leading to apoptotic cell death.