• Journal of Microbiology
• /
• 제42권1호
• /
• pp.64-67
• /
• 2004

The pellets from a culture of Streptomyces coelicolor A3(2) that were submerged shaken were disintegrated into numerous hyphal fragments by DNase treatment. The pellets were increasingly dispersed by hyaluronidase treatment, and mycelial fragments were easily detached from the pellets. The submerged mycelium grew by forming complexes with calcium phosphate precipitates or kaolin, a soil particle. Therefore, the pellet formation of Streptomyces coelicolor A3(2) can be considered a biofilm formation, including the participation of adhesive extracellular polymers and the insoluble substrates.

• Bulletin of the Korean Chemical Society
• /
• 제34권7호
• /
• pp.2117-2124
• /
• 2013

The binding properties and sequence selectivities of ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ (bip = 4,4'-biphenylene (imidazo [4,4-f][1,10]phenanthroline) complexes with $poly[d(A-T)_2]$ and $poly[d(G-C)_2]$ were investigated using conventional spectroscopic methods. When bound to $poly[d(A-T)_2]$, a large positive circular dichroism (CD) spectrum was induced in absorption region of the bridging moiety for both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes, which suggested that the bridging moiety sits in the minor groove of the polynucleotide. As luminescence intensity increased, decay times became longer and complexes were well-protected from the negatively charged iodide quencher compared to that in the absence of $poly[d(A-T)_2]$. These luminescence measurements indicated that Ru(II) enantiomers were in a less polar environment compared to that in water and supported by minor groove binding. An angle of $45^{\circ}$ between the molecular plane of the bridging moiety of the ${\Delta}{\Delta}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex and the local DNA helix axis calculated from reduced linear dichroism ($LD^r$) spectrum further supported the minor groove binding mode. In the case of ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex, this angle was $55^{\circ}$, suggesting a tilt of DNA stem near the binding site and bridging moiety sit in the minor groove of the $poly[d(A-T)_2]$. In contrast, neither ${\Delta}{\Delta}$-nor ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complex produced significant CD or $LD^r$ signal in the absorption region of the bridging moiety. Luminescence measurements revealed that both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes were partially accessible to the $I^-$ quencher. Furthermore, decay times became shorter when bis-Ru(II) complexes bound to $poly[d(G-C)_2]$. These observations suggest that both the ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ complexes bind at the surface of $poly[d(G-C)_2]$, probably electrostatically to phosphate group. The results indicate that ${\Delta}{\Delta}$- and ${\Lambda}{\Lambda}-[{\mu}-Ru_2(phen)_4(bip)]^{4+}$ are able to discriminate between AT and GC base pairs.

• Membrane and Water Treatment
• /
• 제11권3호
• /
• pp.207-215
• /
• 2020

Vivianite (Fe₃²⁺(PO₄)2·8H₂O) and green rust ([Fe₄²⁺Fe₂³⁺(OH)^-₁₂][SO₄^2-·2H₂O]^2-), ferrous containing minerals, could remove aqueous U(VI) in 5 min. and the efficiencies of green rust were roughly 2 times higher than that of vivianite. The zeta potential measurement results implies that the better performance of green rust might be attributed to the favorable surface charge toward uranyl phosphate species. The removal behaviors of the minerals were well fitted by pseudo-second order kinetic model (R² > 0.990) indicating the dominant removal process was chemical adsorption. Effects of Ca²⁺ and CO₃^2- at pH 7 were examined in terms of removal kinetic and capacity. The kinetic constants of aqueous U(VI) were 8 and 13 times lower (0.492 × 10^-3 g/(mg·min); 0.305 × 10^-3 g/(mg·min)) compared to the value in the absence of the ions. The thermodynamic equilibrium calculation showed that the stable uranyl species (uranyl tri-carbonate) were newly formed at the condition. Surface investigation on the reacted mineral with uranyl phosphates species were carried out by XPS. Ferrous iron and U(VI) on the green rust surface were completely oxidized and reduced into Fe(III) and U(IV) after 7 d. It suggests that the ferrous minerals can retard U(VI) migration in phosphate-rich groundwater through the adsorption and subsequent reduction processes.

• BMB Reports
• /
• 제38권2호
• /
• pp.198-205
• /
• 2005

Resveratrol (RES) and genistein (GEN) are the dietary natural products known to possess chemopreventive property and also the ability to repair DNA damage induced by mutagens/carcinogens. It is believed that the therapeutic activity of these compounds could be primarily due to their interaction with nucleic acids but detailed reports are not available. We here explore the interaction of these drugs with nucleic acids considering DNA and RNA as a potential therapeutic target. The interaction of RES and GEN has been analysed in buffered solution with DNA [saline sodium citrate (SSC)] and RNA [tris ethylene diammine tetra acetic acid (TE)] using UV-absorption and Fourier transform infrared (FTIR) spectroscopy. The UV analysis revealed lesser binding affinity with nucleic acids at lower concentration of RES (P/D = 5.00 and 10.00), while at higher drug concentration (P/D = 0.75, 1.00 and 2.50) hyperchromic effect with shift in the ${\lambda}_{max}$ is noted for DNA and RNA. A major RES-nucleic acids complexes was observed through base pairs and phosphate backbone groups with K = $35.782\;M^{-1}$ and K = $34.25\;M^{-1}$ for DNA-RES and RNA-RES complexes respectively. At various concentrations of GEN (P/D = 0.25, 0.50, 0.75, 1.00 and 2.50) hyperchromicity with shift in the ${\lambda}_{max}$ from 260 $\rightarrow$ 263 om and 260 $\rightarrow$ 270 nm is observed for DNA-GEN and RNA-GEN complexes respectively. The binding constant (from UV analysis) for GEN-nucleic acids complexes could not be obtained due to GEN absorbance overlap with that of nucleic acids at 260 nm. Nevertheless a detailed analysis with regard to the interaction of these drugs (RES/GEN) with DNA and RNA could feasibly be understood by FTIR spectroscopy. The NH band of free DNA and RNA which appeared at $3550-3100\;cm^{-1}$ and $3650-2700\;cm^{-1}$ shifted to $3450-2950\;cm^{-1}$ and $3550-3000\;cm^{-1}$ in DNA-RES and RNA-RES complexes respectively. Similarly shifts corresponding to $3650-3100\;cm^{-1}$ and $3420-3000\;cm^{-1}$ have been observed in DNA-GEN and RNA-GEN complexes respectively. The observed reduction in NH band of free nucleic acids upon complexation of these drugs is an indication of the involvement of the hydroxyl (OH) and imino (NH) group during the interaction of the drugs and nucleic acids (DNA/RNA) through H-bonded formation. The interaction of RES and GEN with bases appears in the order of G $\geq$ T > C > A and A > C $\geq$ T > G. Further interaction of these natural compounds with DNA and RNA is also supported by changes in the vibrational frequency (shift/intensity) in symmetrical and asymmetrical stretching of aromatic rings of drugs in the complex spectra. No appreciable shift is observed in the DNA and RNA marker bands, indicating that the B-DNA form and A-family conformation of RNA are not altered during their interaction with RES and GEN.

• Macromolecular Research
• /
• 제12권5호
• /
• pp.501-506
• /
• 2004

We have investigated the spectral properties of DNA, including its electric absorption, circular and linear dichroism (CD and LD), and fluorescence emission, in the DNA-linear polyethyleneimine (LPEI) and DNA-branched polyethyleneimine (BPEI) complexes at various polymer concentrations. The spectral properties of both complexes are similar. We observed a relatively moderate change in the absorption and CD spectra at low amine/DNA phosphate (NIP) ratios (< 0.5), followed by a drastic collapse within the N/P range from 0.8 and 1.0. The absorption and CD spectra recovered as the N/P ratio increased to ca. 1.2. In contrast, the LD and emission of ethidium intercalated between the DNA bases decreased almost linearly at N/P ratios between 0.0 and 1.0. These spectra never recovered at higher N/P ratios. We believe that the moderate changes in the spectrum at low N/P ratios occurred because of electrostatic interactions between DNA and BPEI, while the collapsed spectra at N/P ratios between 0.5 and 1.5 occurred because of condensation/aggregation of the DNA. Considering the structure of the polymers, we suggest that the secondary amino group of LPEI and all three amino groups of BPEI are equally involved in DNA condensation.

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.4084-4092
• /
• 2012

Theoretical calculations based on density functional theory (DFT) were performed to study the substituent effect on the geometric and electronic structures as well as the biological behavior of technetium-99m-labeled diphosphonate complexes. Optimized structures of these complexes are surrounded by six ligands in an octahedral environment with three unpaired 4d electrons ($d^3$ state) and the optimized geometry of $^{99m}Tc$-MDP agrees with experimental data. With the increase of electron-donating substituent or tether between phosphate groups, the energy gap between frontier orbitals increases and the probability of non-radiative deactivation via d-d electron transfer decreases. The charge distribution reflects a significant ligand-to-metal electron donation. Based on the calculated geometric and electronic structures and biologic properties of $^{99m}Tc$-diphosphonate complexes, several structure-activity relationships (SARs) were established. These results may be instructive for the design and synthesis of novel $^{99m}Tc$-diphosphonate bone imaging agent and other $^{99m}Tc$-based radiopharmaceuticals.

• 대한화학회지
• /
• 제19권5호
• /
• pp.325-330
• /
• 1975

철(III) 이온과 인산간의 착물형성에 관하여 넓은 인산산성범위(0${\sim}40{\%}$)에서 가시부스펙트럼과 용액으로 부터 분리해낸 화합물을 검토함으로써 연구하였다. 철(III)함유 인산용액의 전자흡수 스펙트럼은 19.2kK 및 24.1kK에서 철(III)-인산 착물형성을 나타내는 두개의 가시부 흡수를 나타내었다. 24.1kK 밴드의 인산농도에 따른 흡광도 변화의 측정으로부터 아마도 $[Fe(H_xPO_4)]^{x+}\;및\;[Fe_2 (H_xPO_4)]^{(3+x)+}$등 두개의 형태가 틀린 철(III)-인산착물이 존재함을 알 수 있었다. 이들 두화합물중 몰비가 1:1인 착물은 고체상태로 분리하는데 성공하였으며 인산이온은 염기도 1인 상태로 금속에 배위되어 있음을 알 수 있으나, 이합체로 생각되는 화합물은 분리해낼 수 없었다.

• Journal of Pharmaceutical Investigation
• /
• 제25권3호
• /
• pp.227-237
• /
• 1995

Omeprazole(OMP) complexes such as inclusion complexes of OMP with $hydroxypropyl-{\beta}-cyclodextrin$(HPCD) and ${\beta}-cyclodextrin({\beta}-CD)$, OMP-cholestyramine(CHL) and OMP-ethylenediamine(OMP-ED) were prepared, respectively. The partition coefficients in Witepsol H-15 /pH 7.4 phosphate buffer solution of OMP complexes$(OMP-HPCD;\;3.69{\pm}0.26,\;OMP-{\beta}-CD;\;4.08{\pm}0.21,\;OMP-CHL;\;4.36{\pm}0.25\;and\;omeprazole\;sodium(OMP-Na);\;3.64{\pm}0.37)$ were higher than that of OMP $(2.66{\pm}0.47)$. OMP was not completely dissolved until even 3 hrs, but all the OMP complexes studied were released about 100% in 20 min. The rectal suppositories containing OMP or each above OMP complex were prepared using Witepsol H-15 base, and their dissolution and stability were examined, and pharmacokinetic study were investigated after their rectal administrations to the rabbits. While the suppository containing OMP was released only less than 60% in 150 min, $OMP-{\beta}-CD$, OMP-CHL, OMP-Na and OMP-ED suppositories were all released about 65% in 20 min. Especially, OMP-HPCD suppository released OMP about 70% in 10 min. All the additives such as sodium laurylsulfate, eglumine, arginine and PVP increased drug release from OMP-HPCD suppository to some extent. The decomposition rate constants of OMP in the suppositories were $9.117{\times}10^{-3}\;day^{-l}$ for OMP suppository, $2.121{\times}10^{-2}$ for OMP-HPCD, $1.607{\times}10^{-2}$ for $OMP-{\beta}-CD$, $9.26{\times}10^{-3}$ for OMP-Na, $6.769{\times}10^{-3}$ for OMP-CHL and $5.58{\times}10^{-3}\;day^{-l}$ for OMP-ED suppository, respectively. Additives such as arginine, eglumine and ED had some stabilizing effect for OMP-HPCD, OMP-CHL and OMP-Na suppositories, respectively. After 6 month-storage at $30^{\circ}C$, 75% RH, OMP-CHL suppository was most stable. The values of Tmax for OMP-HPCD and OMP-Na suppositories were $11.7{\pm}2.36\;and\;11.4{\pm}2.56\;min$, respectively. The values of Cmax for OMP-HPCD and OMP-CHL suppository were $2.31\;{\mu}g/ml\;(p<0.01)\;and\;1.89\;{\mu}g/ml\;p<0.01)$, respectively. The values of AUC for OMP and $OMP-{\beta}-CD$ suppository were $61.9{\pm}25.79\;and\;68.6{\pm}29.48\;{\mu}g\;{\cdot}\;min/ml$, and the corresponding values for OMP-HPCD and OMP-CHL were $106.1{\pm}43.16\;(p<0.05)\;and\;127.3{\pm}42.52\;{\mu}g\;{\cdot}\;min/ml(p<0.01)$, respectively. The above results indicate the OMP-HPCD and OMP-CHL suppositories have the excellent bioavailabilties in vivo study.

• 자원환경지질
• /
• 제50권3호
• /
• pp.181-193
• /
• 2017

철원 갈말-김화 지역의 쥐라기 복운모 화강암체 내 페그마타이트에서는 다양한 망간-철 인산염광물의 집합체가 산출되고 있으며, 후기 마그마 단계로부터 열수단계 및 지표 풍화 단계에서 다양한 광물상의 변화가 유도되었다. 철원 복운모 화강암은 낮은 대자율 값을 갖는 전형적인 S-형 화강암으로 중알루미나질~고알루미나질, 후-충돌대 환경을 나타내고 있다. 페그마타이트는 K-Ar 연대가 약 153 Ma로서 복운모 화강암의 K-Ar 연대($151{\pm}4Ma$)와 전반적으로 일치하고 있어 동일 기원의 마그마로 추정된다. 한편 갈말-김화 페그마타이트는 광물조성에 의한 분류기준에 의하면 백운모-희유원소 종, 리튬 세부종, 녹주석 유형에 속하는 녹주석-콜롬바이트-인산염광물으로 구분되며, LCT(Li-Cs-Ta) 계열에 해당한다. 망간 인산염광물 중 트리플라이트는 주로 후기 마그마 단계에 정출되었으며, 열수 단계에서는 망간 인산염광물의 변질광물인 루코포스파이트와 잔사이트로 정출되었다. 풍화 단계에서 트리플라이트는 포스퍼시더라이트와 망간 산화물로 교대되어 산출된다.

• Macromolecular Research
• /
• 제15권6호
• /
• pp.581-586
• /
• 2007

Cast DNA/polyethyleneimine (PEI) blend membranes containing different amounts of DNA were prepared using acid-base interaction and characterized with the aim of understanding the polymer electrolyte membrane properties. Two different molecular weights of PEI were used to provide the mechanical strength, while DNA, a polyelectrolyte, was used for the proton transport channel. Proton conductivity was observed for the DNA/PEI membrane and reached approximately $3.0{\times}10^{-3}S/cm$ for a DNA loading of 16 wt% at $80^{\circ}C$. The proton transport phenomena of the DNA/PEI complexes were investigated in terms of the complexation energy using the density functional theory method. In the case of DNA/PEI, a cisoid-type complex was more favorable for both the formation of the complex and the dissociation of hydrogen from the phosphate. Since the main requirement for proton transport in the polymer matrix is to dissociate the hydrogen from its ionic sites, this suggests the significant role played by the basicity of the matrix.