• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.225-232
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• 1988

Poly (L- lactic acid-co-glycine-L-lactic acid) and Poly (L-lactic acid-co-glycine-L- methyl lactic acid ) have been prepared by ring opening polymerization. The monomer 6, 6-dimethyl morpho-line-2, 5-dione was synthesized by the bromoisobutylation of 2-bromoisobutyryl bromide with glycin e. L-lactide, 6-methyl morpholine-2, 5-diode. and 6, 6-dimethyl morpholine-2, 5-diode have been used as starting materials for polydepsipeptides. The synthesized monomers and copolymers have been identified by NMR and FT-lR spa- ctrophotometer. The thermal propert ies and glass transition temperature(Tg) of the copolymers have been measured by differential scanning calorimetry. The Tg values of poly(L-lactic acid co-glycine-L-lactic acid) system are increased from $53^{\circ}C\; to\; 107^{\circ}C$ with increasing the mole fraction of 6-methyl morpholine-2, 5-diode. And the Tg values of poly(L-lactic acid co-glycine-L-methyl lactic acid) system are increased from $53^{\circ}C\;to\;138^{\circ}C$ with increasing the mole fraction of 6. 6-dimethyl morpholine-2, 5-diode The thermal stability of poly (L-lactic acid-co-glycine-L-methyl lactic acid) is slightly greta text than that of poly(L-lactic acid-co-glycine-L-lactic acid) due to the methyl group.

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1052-1054
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• 2000

Binding geometries of $[Ru(II)(110-phenanthroline)_2L]^2+$, complexes (where L = dipyrido [3,2-a:2',3'-c]phena-zine (DPPZ) or benzodipyrido[3,2-a:2',3'-c] phenazine (BDPPZ)) to poly(dG)${\cdot}$poly(dC)${\cdot}$poly(dC) + triplex DNA (CGC + triplex) has been investigated by linear dichroism and normal absorption spectroscopy. Analysis of the linear dichroism for the CGC+ triplex and $[Ru(II)(phen)_2BDPPZ]^2+$ complex indicates that the extended ligand of the metal complex lie perpendicular to the polynucleotide helix axis. Together with strong hypochromism and red shift in the interligand absorption region, we concluded that the extended BDPPZ or DPPZ ligand in-tercalated between the bases of polynucleotide. The spectral properties of the metal complexes bound to CGC+ triplex are similar to those bound to $poly(dA)[poly(dT)]^2$ triplex (Choi et al., Biochemistry 1997, 36, 214), sug-gesting that the metal complex is located in the minor groove of the CGC+ triplex.

• Journal of Animal Science and Technology
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• v.62 no.3
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• pp.385-395
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• 2020

Polyinosinic:polycytidylic acid (poly[I:C]) can stimulate Toll-like receptor 3 (TLR3) signaling pathways. In this study, DF-1 cells were treated with poly(I:C) at various concentrations and time points to examine the comparative expression patterns of innate immune response genes. The viability of DF-1 cells decreased from 77.41% to 38.68% when cells were treated different dose of poly(I:C) from 0.1 ㎍/mL to 100 ㎍/mL for 24 h respectively. The expressions of TLR3, TLR4, TLR7, TLR15, TLR21, IL1B, and IL10 were increased in dose- and time-dependent manners by poly(I:C) treatment. On the contrary, the expression patterns of interferon regulatory factors 7 (IRF7), Jun proto-oncogene, AP-1 transcription factor subunit (JUN), Nuclear Factor Kappa B Subunit 1 (NF-κB1), and IL8L2 were varied; IRF7 and IL8L2 were increasingly expressed whereas the expressions of JUN and NF-κB1 were decreased in a dose-dependent manner after they were early induced. In time-dependent analysis, IRF7 expression was significantly upregulated from 3 h to 24 h, whereas JUN and NF-κB1 expressions settled down from 6 h to 24 h after poly(I:C) treatment although they were induced at early time from 1 h to 3 h. Poly(I:C) treatment rapidly increased the expression of IL8L2 from 3 h to 6 h with a plateau at 6 h and then the expression of IL8L2 was dramatically decreased until 24 h after poly(I:C) treatment although the expression level was still higher than the non-treated control. These results may provide the basis for understanding host response to viral infection and its mimicry system in chickens.

• Journal of Biomedical Engineering Research
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• v.13 no.2
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• pp.147-154
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• 1992

Poly (glycolic aclu-co-glycine-L-lactic aclu) has been prepared by rlng opening polymerlzation. The monomer 6-methyl morpholine-2, 5-dlone was synthe-slzed by bromoproplonylation of 2 bromopropionyl bromide with glycine. Glycolide and 6-methyl morpholine-2, 5-dione have been used as starling materials for polydepsipeptides. The synthesized copolymers have been Identlrled by NMR and FT-lR spectrophotometer. The Tg value of poly(glycollc aclu-co glycine-L-tactic acld ) Is In creased with increasing mole fraction of 6-methylmorpholine-2, 5-dlone(60-$84^{\circ}C$). The glass trasltion temperature of poly(glycolic acid-co-glycine-L-lactic-acid) (62-$86^{\circ}C$) is lower than that of poly (L-lactic acrid-co-glycine-L-lactic acid ). The thermal degradation of poly( L-lactic acid-co- glycine-L-lactic acid ) Is decreased with increasing mole fraction of L-lactide. The thermal degrada pion of poly(glycolic acrid-co-91ycine-L-lactic aclu ) is increased with increasing mole Fraction of glycolide.

• Polymer(Korea)
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• v.24 no.4
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• pp.477-487
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• 2000

A series of poly(L-lactic acid) (PLLA)/poly($\beta$-hydroxynonanoate) (PHN) blend were prepared to study the miscibility and the crystallization behaviors. The thermal behaviors and characterization of PLLA/PHN blends Were studied using differential scanning calorimetry (DSC), XRD and polarizing optical microscopy (POM). The PLLA and PHN are partially miscible in amorphous region. The crystallinity of PLLA increased as the content of PHN increased, and T$_{g}$, T$_{c}$, and T$_{m}$ of PLLA shift as the content of PHN increased. Moreover, the number of PLLA spherulite increased as the content of PHN increased in the POM experiment. Thus, PHN acted as a nucleating agent to PLLA.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.614-620
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• 1994

The effects of growth temperature and nutritional components on the synthesis of poly-3-hydroxybutyric acid, PHB, by filamentation-suppressed recombinant Escherichia coli XL1-Blue (pSYL107) were studied. After culturing XL1-Blue(pSYL107) for 48 hours in complex medium at 30$\circ$C, 7Al g/l of PHB could be obtained with the PHB content and PHB yield of 82% and 0.371 g PHB/g glucose, respectively. Lower concentration of PHB(3.2 g/l) was obtained when cultu- red at 37$\circ$C, which seemed to be due to the instability of this strain having amplified FtsZ activity. The PHB concentration of 3.75 g/l was obtained after culturing 60 hours in R medium supplemen- ted with 20 g/l glucose at 30$\circ$C, which was more than twice higher than that obtained with XL1-Blue(pSYL105). This suggested that the enhancement of PHB synthesis by suppressing filamenta- tion was more significant in a defined medium than complex medium. PHB synthesis could be further enhanced by supplementing a small amount of various complex nitrogen sources. When 5 g/l of beef extract was added to a defined medium, PHB concentration, PHB content, and PHB yield obtained after 60 hours of cultivation at 30$\circ$C were 7.46 g/l, 86%, and 0.375 g PHB/g glucose,respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1869-1874
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• 2010

By reducing PVP with $H_2NOH$.HCl and NaOH 2:2:1 mass ratios in aqueous ethanol, poly-N-vinyl pyrrolidone oxime [PVPO] was prepared with 92% yield. Applying the sol-gel concept, orthosilicic acid [OSA] was made by hydrolyzing TEOS with ethanol in 1:0.5 molar ratios using 1 N KOH aqueous solution as a catalyst. The OSA + PVPO + $_L$-Valine ($\alpha$-amino acid) were mixed with pure ethanolic medium in 1:2:2 mass ratios and refluxed at $78^{\circ}C$ and 6 pH for 6.5 h. A white residue of poly-N-vinyl pyrrolidone oximo-L-valyl-siliconate [POVS] appeared after 5 h. The heating of reaction mixture was stopped and the contents were brought to NTP. The residue formation of POVS was intensified with lowering a temperature and completely solidified within 5 h, was filtered using a vacuum pump with Whatmann filter paper no. 42. The residue of POVS was washed several times with 20% aqueous cold ethanolic solution and dried in vacuum chamber at $25^{\circ}C$ for 24 h. The MP was noted above $350^{\circ}C$. Structural and internal morphology were analyzed with IR and $^1H$-NMR, and SEM respectively. A drug loading and transporting ability of the POVS in water and at pH = 5 and 8 was determined chromatographically.

• KSBB Journal
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• v.19 no.5
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• pp.358-362
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• 2004

Characteristics of cell growth and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] synthesis was investigated through flask and batch cultures of Alcaligenes latus and Comamonas acidovorans. The specific growth rate of C. acidovorans increased with yeast extract concentration and decreased with 1,4-butanediol concentration. Optimum glucose concentration for growth of C. acidovorans was 20 g/L. In one-step flask cultures of C. acidovorans, final dry cell weight and PHA content decreased with the ratio of 1,4-butanediol to glucose, while the 4HB fraction in copolymers gradually increased to 100 $mol\%$ with an initial 1,4-butanediol concentration of 20 g/L as single carbon source. The specific growth rate of A. latus decreased with v-butyrolactone concentration and optimum sucrose concentration for growth was 10 g/L. In batch cultures of A. latus, 4HB fraction increased with initial v-butyrolactone concentration. P(3HB-co-4HB) with 19 $mol\%$ 4HB was obtained when the initial ratio of v-butyloractone (g/L) to sucrose (g/L) was 10 : 10.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.273-279
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• 1990

For poly- $\beta$ -hydroxybutyrate (PHB) production, a pink-pigmented facultative methylotrophic bacterium (PPFM) P-10 was newly isolated from soils through methanol-enrichment culture. The optimal medium composition for cell growth was 1.0% (vlv) of methanol as carbon source and l.Og/l of ,TEX>$NH_4Cl$, equivalent to C/N ratio of 13.2 at pH 7.0 and $30^{\circ}C$. To investigate the optimal condition for YHB accumulation, two-stage culture technique was adopted; first stage for cell growth and second stage for accumulation of PHB providing unbalanced growth conditions. The optimal PHB accumulation was 1.0% (vIv) of methanol and 0.26gll of $NH_4Cl$, C/N of 50.8 at pH 6.0. To overcome methanol inhibition on cell growth, intermittent feeding fed-batch culture technique was employed, and the cell concentration as high as 14gll with 40% of PHB was achieved. The purified PHB was identified using IR and $1^H NMR$ as homopolymer of 8hydroxybutyric acid. The absorption spectrum of extracted pink colored microbial pigment was alsa investigated.

• Archives of Pharmacal Research
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• v.17 no.2
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• pp.93-99
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• 1994

Macrtophages play an important role in defense against virus infection by intrinsic resistance and by extrinsic resistance. Since interferon-induced enzymes which are 2'-5' oligoadenylate synthetase and p1/eIF-2 protein kinase have been shown to be involved in the inhibition of viral replication, I examined the mechanism by which poly I:C, an interferon inducer, exerts its antiviral effects in inflammatory macrophages infected with herpes simplex virus type 1 (HSV-1). The data presented here demonstrate that poly I:C-induced antiviral activity is partially due to the activation of 2'-5' pligoadenylate synthetase. The activation of 2'-5' oligoadenlate A synthetase by poly I:C is also at least mediated via the production of interferon-.betha.. Taken together, these data indicate that interferon-.betha. produced in response to poly I:C acts in an autocrine manner to activate the 2'-5' oligoadenylate synthetase and to induce resistance to HSV-1.