• Korean Journal of Microbiology
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• v.13 no.2
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• pp.64-70
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• 1975

As a serial experiment of radiosterilization of medical products, we investigated the feasibility of using gamma ray to sterilize antibiotics, tetracycline HCl. Tetracycline HCl in aqueous solution and dried state irradiated with several dose levels was assayed for physico-chemical properties by checking UV absorption spectra, paper chromatogrph. IR spectra and NMR sepctra, and antibiotic activities by [means of agar plaque technique and tube $d_1$]ution method. In physico-chemical propertis and biological activities, the teracycline HCl in dried state remained radioresistant up to exposure of 10 Mrad, however, in aqueous solution, the dose of 300 Krad produced a significant inactivation. From the results of this study, radiosterilization of tetracycline HCl is more recommendable in the dried state than in aqueous solution.

• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.15-19
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• 2012

A new cyclic peptide (six-membered amino acid), gamakamide-E (L-Leu-L-Met (SO)-L-Me-Phe-L-Leu-D-Lys-L-Phe), was isolated as a strongly bitter tasting compound from cultured oysters, Crassostrea gigas. The molecular formula of $C_{43}H_{61}N_7O_8S$ was deduced from high resolution fast atom bombardment mass spectrometry (HR FAB-MS) ($[M+H]^+$ m/z 836.4356 ${\Delta}$= -2.4 mmu). Its unique structure including a hydantoin structure was firstly elucidated by nuclear magnetic resonance (NMR) analysis. Stereochemistries of constituent amino acids were determined by chiral high performanced liquid chromatography analysis of natural and synthesized peptides.

• KSBB Journal
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• v.15 no.6
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• pp.560-565
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• 2000

13-Deacetyl-taxchinin I, a taxoid having a rearranged 11(15\longrightarrow1)-abeo-taxane skeleton, has been isolated and identified from plant cell cultures of Taxus chinensis. The compound has not previously been encountered in nature. Its structure was elucidated by 1-and 2D NMR techniques including H-H COSY, HMQC, and HMBC experiments. This taxoid also provides information for better understanding of structure-activity relationships and biosynthesis, as well as improving the quality control of paclitaxel production.

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.441-445
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• 2002

Three naphthalene glycosides (1-3), four flavonoids (4-7), and two galloyl glycosides (8-9) were isolated from the stem-bark of Juglans mandshurica (Juglandaceae). Their structures were determined by chemical and spectral means, including to 2D-NMR (COSY, HMQC, and HMBC) experiments. Amongst the isolated compounds, taxifolin (4) showed the most potent HIV-induced cytopethic activity against MT-4 cells with complete inhibitory concentration ($IC_{100}$) value of $25{\;}{\mu\textrm{g}}/ml$ and maximum cytotoxic concentration ($CC_{100}$) value of above $100{\;}{\mu\textrm{g}}/ml$. However, naphthalene glycosides (1-3), flavonoids (5-7)), and galloyl tannins (8-9) were inactive against anti-HIV-1 activity.

• Bulletin of the Korean Chemical Society
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• v.20 no.8
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• pp.905-909
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• 1999

Reaction of tetrahomodioxa p-phenylcalix[4]arene with ethyl bromoacetate and potassium carbonate in ace-tone leads to the title tetra ester derivative, 7,13,21,27-tetra-phenyl-29,30,31,32 -tetrakis(ethoxycarbonyl)meth-oxy-2,3,16,17-tetrahomo-3,17-dioxacalix[4]arene, its structure was determined by NMR spectra as 1,4-alternate conformation. The molecular structure has been solved by X-ray diffraction methods. The molecule has a conformation with pseudo center of symmetry. The benzene ring A is up, ring C is down, B and D rings are flat with respect to the plane of the macrocyclic ring.

• Bulletin of the Korean Chemical Society
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• v.21 no.4
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• pp.383-388
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• 2000

Multiblock copolymers consisting of poly( g-benzyl L-glutamate) (PBLG) as the hydrophobic part and poly(ethylene oxide) (PEO) as the hydrophilic part (GEG) were synthesized and characterized. GEG polymeric micelles were prepared by the dialysis technique. Particle size distributions based on intensity,volume, and number-average were 22.6 $\pm$ 11.9 nm, 23.5 $\pm$ 4.6 nm, and 23.7 $\pm$ 37 nm, respectively. It was observed that par-ticle size and size distribution of GEG polymeric micelles changed significantly with the choice of initial sol-vent. Transmission electron micrographs (TEM) showed the polymeric micelles to be spherically shaped, with sizes ranging from 20 nm to 40 nm in diameter. Fluorescence spectroscopy measurements suggested that GEG block copolymers wereassociated in water to form polymeric micelles, and the critical micelle concentrations (CMC) value of the block copolymers was 0.0094 g/L. Further evidenceof micelle formation of GEG block copolymers and limited mobility of the PBLG chain in the core ohe micelle was obtained with 1 H NMR in D2O.

• Archives of Pharmacal Research
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• v.11 no.2
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• pp.114-121
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• 1988

To gain insight into possible cellular protective mechanisms against the insult of formaldehyde, we have investigated this molecule's reactivity with both naturally occurring thiol compounds including glutathione and L-ascorbic acid. By UV measurements, for maldehyde was found to rapidly react with glutathione forming an S-hydroxymethyl covalent adduct. The adduct which was confirmed by NMR is transiently stable. Formaldehydissimilar to its reaction with dimedone. The reaction of formaldehyde with glutathione was reduced by 40% in the presence of an excess amount of L-ascorbic acid, due to the trapping of formaldehyde by L-ascorbic acid. The data suggest that L-ascorbic acid may have a possible in vivo role in the metabolism of formaldehyde, thereby protecting cellular glutathione from possible depletion.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.1060-1063
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• 2007

The antioxidative activity of Alpinia oxyphylla was investigated through measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and inhibitory activity for linoleic acid peroxidation. Two antioxidative diarylheptanoids, yakuchinone A (1) and oxyphyllacinol (2), were isolated from the fruits of A. oxyphylla using thin layer chromatography (TLC) autographic assays. The DPPH scavenging activities of the compounds ($IC_{50}=1$, $57{\pm}2.1\;{\mu}M$; 2, $89{\pm}3.1\;{\mu}M$) were lower than vitamin C ($IC_{50}=51{\pm}1.1\;{\mu}M$), but higher than butylated hydroxytoluene (BHT, $IC_{50}=99{\pm}2.2\;{\mu}M$). Also, inhibitory activities for linoleic acid peroxidation of the compounds ($IC_{50}=1$, $0.19{\pm}0.011\;mM$; 2, $0.31{\pm}0.009\;mM$) were higher than those of vitamin C ($IC_{50}=0.59{\pm}0.017\;mM$) and BHT ($IC_{50}=0.52{\pm}0.014\;mM$). In addition the $^{13}C-NMR$ data of oxyphyllacinol (2) have been first reported in this paper.

• Molecules and Cells
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• v.24 no.3
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• pp.437-440
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• 2007

$OGL-20P^T$-358 is a novel 66 amino acid residue protein from the hyperthermophile Thermococcus thioreducens sp. nov., strain $OGL-20P^T$, which was collected from the wall of the hydrothermal black smoker in the Rainbow Vent along the mid-Atlantic ridge. This protein, which has no detectable sequence homology with proteins or domains of known function, has a calculated pI of 4.76 and a molecular mass of 8.2 kDa. We report here the backbone $^1H$, $^{15}N$, and $^{13}C$ resonance assignments of $OGL-20P^T$-358. Assignments are 97.5% (316/324) complete. Chemical shift index was used to determine the secondary structure of the protein, which appears to consist of primarily ${\alpha}$-helical regions. This work is the foundation for future studies to determine the three-dimensional solution structure of the protein.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.289-298
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• 1996

Eight kinds of poly(oxyethylene, oxyisopropylene) dodecyl ethers were synthesized by adding ethylene oxide and isopropylene oxide with each 5 and 10 moles alternatively on dodecanol. The addition of EO and PO for eight kinds of sodium poly(oxyethylene, oxyisopropylene) dodecyl ether sulfates was identified with HPLC, $^1H$ NMR, hydroxy value, and IR spectrum. In order to verify the sulfation the number of EO and PO molecules was obtained by spectra and Epton method. The yields of products sulfated by chlorosulfonic acid were 90~96%.