• YAKHAK HOEJI
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• v.36 no.2
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• pp.159-166
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• 1992

A neoglycolipid, N-stearyl lactobionamide(N-SLBA) was synthesized and the incorporation of the neoglycolipid into liposomes was achieved in order to prepare neo-galactosylated liposome as potential drug carrier for active targeting to galactose receptor existing cell and tissue. N-SLBA was synthesized by the covalent linkage between carboxyl group of lactobionic acid and amino group of stearylamine(SA). The yield of N-SLBA was about 52.3%. It was identified with $1650\;cm^{-1}$ in IR chart, 7.5 ppm in NMR spectra, $61^{\circ}C$ endothermic peak in DSC heating curve. Surface-modified large unilamellar vesicle with galactose(N-SLBA-LUV) could be prepared with N-SLBA by reverse evaporation method. N-SLBA-LUV was identified by TEM and measuring of membrane function. The maximum amount of N-SLBA incorporated into liposome is up to about 15 mol%. Compared with control liposome (SA-LUV), N-SLBA-LUV showed lower encapsulation efficiency of MTX. It might due to the loss of positive surface charge of stearylamine. N-SLBA-LUV was similar to SA-LUV in aspect of osmotic behavior. N-SLBA-LUV prepared with N-SLBA would be expected to be a good carrier for active targeting to galactose receptor existing cell and tissue.

• KSBB Journal
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• v.15 no.5
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• pp.537-540
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• 2000

In developing a HPLC purification process, it was hoped that a single chromatographic system would be sufficient to abtain pure paclitaxel in high yield. However, no such system was found, due in part to the complex taxoid profile of crude paclitaxel and to the rigorous nature of the product specification. A two step HPLC purification was adopted using reverse-phase separation on C(sub)18 as a first step, and normal-phase separation on silica as the final polishing step. Impurity profiles were established and maintained for paclitaxel, which identified and quantified each impurity observed in purified paclitaxel from these two steps, all impurities at or above 0.1% were identified. Results provide information for improving the quality control of paclitaxel production.

• KSBB Journal
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• v.31 no.4
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• pp.300-311
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• 2016

Recently gene delivery has been designed newly using bioactive biomaterial and applied in the various field by many researchers. In this study, we proposed a new gene delivery system which has the capability of targeting effect in the specific tissue and remarkably enhanced transfection efficiency. We investigated $^1H-NMR$ spectroscopy, particle size analyzer and gel retardation to confirm the correct preparation of gene delivery. Also, we identified the hemo-compatibility of gene delivery by hemolysis assay, non-cytotoxicity by MTT test and transfection efficiency. The uptake mechanism of the gene carrier was confirmed using inhibitor agent such as sodium azide, indomethacin, quercetin, colchicine, and chloropromazine. As a results, it was identified that gene carrier prepared by in this study entered in the cell by the microtubule-dependent, energy-dependent and clathrin-mediated endocytosis pathway.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.81-85
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• 2002

Oligotrophic bacteria isolated from forest soil showed a specific community consisting of various taxonomic groups compared with those in other soil or aquatic habitats. Based on the cell shape, the isolates were divided into four groups: regular rod, curved/spiral rod, irregular rod, and prosthecate bacteria. The cellular fatty acids 60 oligotrophic isolates were analyzed. At the dendrogram based on cellular fatty acid composition, four clusters(I-IV) were separated at a euclidian distance of about 50. Based on the 16S rDNA sequence analysis, the two representative strains(MH256 and MA828) of cluster 3 showed the close relation to genera, Xathomonas/Stenotrophomonas, but were not included in these genera. The isolates with Q-10 were also studied. They are corresponded to the two large groups in Proteobacteria alpha subdivision. One was incorporated in the genus Bradyrhizobium cluster, which also includes Agromonas, a genus for oligotrophic bacteria. The strains of the other group showed high similarity to the genus Agrobacterium. We attempted to screening of bioactive compounds from oligotrophs which was isolated from forest soil. The active compounds were analyzed by mass and NMR spectrum, one of them identified as crisamicin A. Another one designated as SAPH is a new compound. The results indicate that there were possibilities for finding new compounds from the rare microorganisms such as oligotrophs.

• Biomolecules & Therapeutics
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• v.5 no.2
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• pp.125-132
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• 1997

Cisplatin, a platinum-complex, is currently one of the most effective compounds used in the treat-ment of solid tumors. However, its use is limited by severe side effects such as renal toxicity. Our platinum-based drug discovery program is aimed at developing drugs capable of diminishing toxicity and improving selective cytotoxicity. We synthesized new Pt (II) complex analogue containing 1,2-diaminocyclohexane (DACH) as carrier ligand and 1,2-bis (diphenylphosphino) ethane (DPPE) as a leaving group. Furthermore, nitrate was added to improve the solubility. A new series of [Pt(cia-DACH)(DPPE)] . $2NO_3$ (PC) was synthes-ized and characterized by their elemental analysis and by various spectroscopic techniques [infrared (IR), $_{13}$carbon nuclear magnetic resonance (NMR)] .PC demonstrated acceptable and significant antitumor activity against SKOV-3 and OVCAR-3 human ovarian carcinoma cell lines as compared with that of cisplatin. The cytotoxicity of PC in normal cells was found quite less than that of cisplatin using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), ($^3$H)thymidine uptake and glucose consumption tests in rabbit renal proximal tubular cells, human renal cortical cells and tissues. In conclusion, PC is considered to be more selective cytotoxicity toward human ovarian cancer cells than normal human/rabbit kidney cells.

• Korean Journal of Veterinary Research
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• v.31 no.3
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• pp.319-327
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• 1991

Gingko biloba is one of the oldest trees on earth. It can be traced 300 million years or more into past. In recent years, this tree has become increasingly popular because of its longevity. Amount of comsumption of Gingko leaves in Korea is increased to produce drugs for blood circulating system's disorder. The workers who work at the company of product drug with Gingko leaves complain pruritus at belt position of west, however toxic substance from extracts of Gingko biloba was carried out to determine what kind of the toxic substance from extract could induce a contact dermatitis by means of histopathological study. Dried leaves of Korean G. biloba were exhaustively extracted with chloroform. The aqueous chloroform residue was extracted with hexane. After evaporation, the hexane extract was passed through a silica gel column chromatography, it was separated into 9 fractions by means of gradient solvent (benzene: acetone/ 98~93 : 2~7%). The 4th and 7th fraction were idendified as bilibol and gingkolic acid by silica gel thin layer chromatography and NMR spectrophotometer. The 4th and 7th fractions of Korean Gingko leaves have an irritant substances which can be induced ear swelling and increased thickness of stratum cornium of rabbit ear exposed with the fractions (3 time/3 day, $100{\mu}l$ of 50mg/ml ethyl alcohol). In the 4th fraction, the substance have induced the surface of ear to swell and mass of unknown cell like inflammatory cell were infiltrated within the stratum corneum, and the 7th fraction have the surface of ear to loss the hairs, and sebaceous gland and follicle of hair were infiltrated with inflammatory cells. and other fractions at all did not induced a certain contact dermatitis and also Deutschen drug of Gingko (named as Gerigeron) have induced the contact dermatitis such as dematitis of Korean Gingko extract.

• Archives of Pharmacal Research
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• v.29 no.1
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• pp.50-58
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• 2006

Translationally controlled tumor protein (TCTP), also known as histamine releasing factor (HRF), is found abundantly in different eukaryotic cell types. The sequence homology of TCTP between different species is very high, belonging to the MSS4/DSS4 superfamily of proteins. TCTP is involved in both cell growth and human late allergy reaction, as well as having a calcium binding property; however, its primary biological functions remain to be clearly elucidated. In regard to many possible functions, the TCTP of Plasmodium falciparum (Pf) is known to bind with an antimalarial agent, artemisinin, which is activated by heme. It is assumed that the endoperoxide-bridge of artemisinin is opened up by heme to form a free radical, which then eventually alkylates, probably to the Cys14 of PfTCTP. Study of the docking of artemisinin with heme, and subsequently with PfTCTP, was carried out to verify the above hypothesis on the basis of structural interactions. The three dimensional (3D) structure of PfTCTP was built by homology modeling, using the NMR structure of the TCTP of Schizosaccharomyces pombe as a template. The quality of the model was examined based on its secondary structure and biological function, as well as with the use of structure evaluating programs. The interactions between artemisinin, heme and PfTCTP were then studied using the docking program, FlexiDock. The center of the peroxide bond of artemisinin and the Fe of heme were docked within a short distance of $2.6{\AA}$, implying the strong possibility of an interaction between the two molecules, as proposed. When the activated form of artemisinin was docked on the PfTCTP, the C4-radical of the drug faced towards the sulfur of Cys14 within a distance of $2.48{\AA}$, again suggesting the possibility of alkylation having occurred. These results confirm the proposed mechanism of the antimalarial effect of artemisinin, which will provide a reliable method for establishing the mechanism of its biological activity using a molecular modeling study.

• Journal of Microbiology and Biotechnology
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• v.16 no.7
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• pp.1090-1096
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• 2006

O-Methylation is a common modification reaction found in nature, and is mediated by an O-methyltransferase (OMT). OMTs have been mainly studied in plants, whereas only a few OMTs have been studied in microbes. When searching the Bacillus cereus genome, four putative small molecular OMTs were identified, among which BcOMT-1 was cloned and expressed in E. coli as a his-tag fusion protein. The whole cell expressing BcOMT-1 was used to methylate several flavonoids. Eriodictyol, luteolin, quercetin, and taxifolin, all of which contain 3' and 4' hydroxyl groups, served as methyl group acceptors for BcOMT-1, whereas naringenin, apigenin, 3,3'-dihydroxyflavone, and 3,4'-dihydroxyflavone did not function as substrates. Analysis of the reaction products using HPLC showed two different peaks, and NMR revealed that the methylation position was at the hydroxyl group of either carbon 3' or 4'. Therefore, this showed that BcOMT-1 used flavonoids containing ortho hydroxyl groups and transferred a methyl group to either of two hydroxyl groups.

• The Plant Pathology Journal
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• v.23 no.3
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• pp.180-186
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• 2007

The biocontrol agent, Serratia plymuthica A21-4, has been developed for controlling pepper Phytophthora blight. Serratia plymuthica A21-4 strongly inhibits the mycelial growth, zoospore formation, and cyst germination of Phytophthora capsici in vitro. The application of a cell suspension of strain A21-4 to pepper plants in pot experiments and in greenhouse successfully controlled the disease. The bacteria produced a potent antifungal substance which was a key factor in the suppression of Phytophthora capsici. The most active chemical com-pound was isolated and purified by antifungal activity-guided fractionation. The chemical structure was identified as a chlorinated macrolide $(C_{23}H_{31}O_8Cl)$ by spectroscopic (UV, IR, MS, and NMR) data, and was named macrocyclic lactone A21-4. The active compound significantly inhibited the formation of zoosporangia and zoospore and germination of cyst of P. capsici at concentrations lower than $0.0625{\mu}g/ml$. The effective concentrations of the macrocyclic lactone A21-4 for $ED_{50}$ of mycelial growth inhibition were $0.25{\mu}g/ml,\;0.25{\mu}g/ml,\;0.30{\mu}g/ml \;and\;0.75{\mu}g/ml$ against P. capsici, Pythium ultimum, Sclerotinia sclerotiorum and Botrytis cinerea, respectively.

• Journal of Microbiology and Biotechnology
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• v.19 no.11
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• pp.1348-1354
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• 2009

Bioconversion of the isoflavonoid genistein to 2'-hydroxygenistein (2'-HG) was performed using isoflavone 2'-hydroxylase (CYP81E1) heterologously expressed in yeast. A monohydroxylated product was analyzed by liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) and NMR spectrometry and was identified as 2'-HG. An initial bioconversion rate of 6% was increased up to 14% under optimized conditions. After recovery, the biological activity of 2'-HG was evaluated. Bioconverted 2'-HG showed higher antioxidant activity against 1,1-diphenyl-2-picryl hydrazine (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals than did genistein. Furthermore, 2'-HG exhibited greater antiproliferative effects in MCF-7 human breast cancer cells than did genistein. These results suggest that 2'-hydroxylation of genistein enhanced its antioxidant activity and cell cytotoxicity in MCF-7 human breast cancer cells.