• 대한화학회지
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• 제56권2호
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• pp.228-235
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• 2012

$N_2O_2$계 시프염기 리간드인 N,N'-bis(4-methoxysalicylidene)phenylendiamine(4-$CH_3O$-salphen)을 합성하였다. 합성한 4-$CH_3O$-salphen을 이용하여 분광광도법으로 수용액 중의 Cu(II)이온 정량실험을 시도하였다. Cu(II)이온 정량을 위한 최적 실험조건을 구한 결과, 4-$CH_3O$-salphen 농도는 $2.0{\times}10^{-4}\;mol/L$, 용매 DMSO와 물의 비율은 50/50(v/v), pH는 5.5에서, 온도는 $55^{\circ}C$에서 한 시간정도를 물중탕하고, 시료의 흡광도는 388 nm였고, 그 조건에서 검량곡선을 작성하였다. 작성된 검량곡선(${\varepsilon}=3.6{\times}10^4\;mol^{-1}cm^{-1}$)은 $R^2$=0.9963의 상관계수 값을 나타내었다. 이상의 최적화된 실험조건을 이용하여 온천수, 반도체 공장폐수 및 하수 처리장의 처리수를 채취하여 Cu(II)이온을 각각 정량 분석한 결과는 측정 평균값이 기준 값에 대하여 0.6~5.4% 범위에서 잘 일치 하였고, 정량한계는 31.77 ng/mL($5.0{\times}10^{-7}\;mol/L$)이었다.

• 대한화학회지
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• 제55권3호
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• pp.463-471
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• 2011

[ $N_2O_2$ ] 시프염기 리간드인 N,N'-bis(4-methoxysalicylidene) phenylendiamine(4-$CH_3O$-salphen)을 합성하였다. 분광광도법으로 4-$CH_3O$-salphen을 이용하여 수용액 중의 Fe(II)와 Fe(III)이온의 분리 정량실험을 위하여, 리간드 농도는 $4.0{\times}10^{-4}\;M$, DMF 용매와 물의 비율은 70/30(v/v), pH는 3.4~3.8 범위, 온도는 $55^{\circ}C$에서 1 시간 정도를 물 중탕하여 결과를 얻었다. 시료의 예비 산화 및 환원 전처리는 $5.0{\times}10^{-4}\;M$ 농도의 $H_2O_2$와 $NH_2OH{\cdot}HCl$을 사용하여 단일 원자가 상태의 시료를 만들어 사용하였다. 이때 Fe(II)와 Fe(III) 이온의 정량은 434 nm와 456 nm에서 흡광도를 측정하였다. 이상의 최적화된 실험조건을 이용하여 약수, 온천수, 바닷물 및 하수 처리장의 처리수를 채취하여 Fe(II)와 Fe(III) 이온을 각각 정량 분석한 결과는 측정 평균값이 표준 값에 대하여 2.00~6.90% 범위에서 잘 일치 하였고, 정량검출한계는 Fe(II)의 경우 27.9 ng/mL이었고, Fe(III)은 55.8 ng/mL이었다.

• BMB Reports
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• 제38권1호
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• pp.58-64
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• 2005

Myo-inositol monophosphate phosphatase (IMPP) is a key enzyme in the phosphoinositide cell-signaling system. This study found that incubating the IMPP from a porcine brain with pyridoxal-5'-phosphate (PLP) resulted in a time-dependent enzymatic inactivation. Spectral evidence showed that the inactivation proceeds via the formation of a Schiff's base with the amino groups of the enzyme. After the sodium borohydride reduction of the inactivated enzyme, it was observed that 1.8 mol phosphopyridoxyl residues per mole of the enzyme dimer were incorporated. The substrate, myo-inositol-1-phosphate, protected the enzyme against inactivation by PLP. After tryptic digestion of the enzyme modified with PLP, a radioactive peptide absorbing at 210 nm was isolated by reverse-phase HPLC. Amino acid sequencing of the peptide identified a portion of the PLP-binding site as being the region containing the sequence L-Q-V-S-Q-Q-E-D-I-T-X, where X indicates that phenylthiohydantoin amino acid could not be assigned. However, the result of amino acid composition of the peptide indicated that the missing residue could be designated as a phosphopyridoxyl lysine. This suggests that the catalytic function of IMPP is modulated by the binding of PLP to a specific lysyl residue at or near its substrate-binding site of the protein.

• 대한핵의학회지
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• 제29권1호
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• pp.110-117
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• 1995

Tc-99m Labeled hexamethylenepropyleneamineoxime ([$^{99m}Tc$]-HMPAO) is a famous amino-oxime compound and is widely used to construct SPECT images of cerebral blood flow. To investigate the relationship between chemical structure and radiolabeling in these kind of diamine-oxime compounds, we synthesized seven compounds by Schiff's base formation and successive reduction with sodium borohydride. They were (RR/SS )-4,8-diaza-3,6,6,9-tetramethylundecane-2,10-dione bisoxime (2), (RR/SS/meso)-4,8-diaza-3,9-dimethy-lundecane-2,10-dione bisoxime (4), (RR/SS/meso)-4,8-diaza-3,10-dimethyldodecane-2,11-dione bisoxime (5), (RR/SS/meso)-4,7-diaza-3,6,6,8-tetramethyldecane-2,9-dione bisoxime (8), (RR/SS/meso)-4,7-diaza-5,6-cyclohexyl-3,8-dimethyldecane-2,9-dione bisoxime (10), (RR/SS/meso)-3,4-bis(1-aza-2-methyl-3-oxime-1-butyl)-benzoic acid (12), and (RR/SS/ meso)-2,3-bis(1-aza-2-methyl-3-oxime-1-butyl) benzophenone (14). Chemical structures of all the synthesized compounds were identified by taking $^1H$ spectrum. Among them, 2 and 4 are propyleneamine oxime (PnAO), 6 is butyleneamine oxime (BnAO) and 8, 10, 12 and 14 are ethyleneamine oxime (EnAO). Each compound (0.5 mg) was incubated with stannous chloride (0.5 g - 8 g), carbonate-bicarbonate buffer (final concentration = 0.1 M, pH 7 - pH 10) and Tc-99m-pertechenate (1 ml). Tc-99m labeling of these compounds were checked by ITLC (acetone), ITLC (normal saline), reverse phase TLC (50 % acetonitrile) and ITLC (ethyl acetate). According to the results, EnAO's were not labeled by Tc-99m in any of above condition. About 11 % of maximum labeling efficiency was obtained with BnAO. However, 4 (PnAO) was labeled with Tc-99m to 85 % which is similar to the labeling efficiency of 2 (HMPAO). Hydrophilic impurity (9 % ) was the most significant problem with the labeling of 4, however, pertechnetate (3 % ) and colloid (3 %) were minor problem. In conclusion, we synthesized seven diamine blsoxlme compounds. Among them, four EnAO compounds were not labeled by Tc-99m. A BnAO was labeled poorly and two PnAO's were labeled well. These labeling can be explained by tertiary structure of their Tc-99m chelate.

• 대한화학회지
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• 제54권5호
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• pp.573-578
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• 2010

본 연구에서는 염화제1철을 2,4-디히드록시살로펜과 조합하여 2,4-디히드록시살로펜-염화철을 합성하였다. 이 복합체를 자외선-가시광선 분광법, IR 분광법으로 분석하였고, 천연의 송아지 흉선 DNA (ct-DNA)와 2,4-디히드록시살로펜-염화철의 상호작용을 자외선-가시광선 분광법, 형광분광법, 열변성 분석법, 점성측정법을 이용하여 조사하였다. 분광학적 적정실험으로 밝힌 2,4-디히드록시살로펜-염화철과 ct-DNA 사이의 결합상수는 $(1.6{\pm}0.2){\times}10^3\;M^{-1}$이었다. 형광분광분석을으로 브롬화 에티디움의 DNA 결합이 2,4-디히드록시살로펜-염화철에 의하여 저해되는 것을 관찰하였다. 이 저해효과는 2,4-디히드록시살로펜-염화철의 농도에 따라 선형의 Stern-Volmer 방정식을 따른다. 열변성 실험으로 2,4-디히드록시살로펜-염화철이 DNA의 녹는점을 약 $4.3^{\circ}C$ 증가시킨다는 것을 관찰하였다. 이 결과들은 2,4-디히드록시살로펜-염화철이 대부분 ct-DNA의 큰고랑과 상호작용한다는 모델을 잘 설명하여 준다.

• Animal Bioscience
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• 제35권11호
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• pp.1787-1799
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• 2022

Objective: Choline deficiency, one main trigger for nonalcoholic fatty liver disease (NAFLD), is closely related to lipid metabolism disorder. Previous study in a choline-deficient model has largely focused on gene expression rather than gene structure, especially sparse are studies regarding to alternative splicing (AS). In modern life science research, primary hepatocytes culture technology facilitates such studies, which can accurately imitate liver activity in vitro and show unique superiority. Whereas limitations to traditional hepatocytes culture technology exist in terms of efficiency and operability. This study pursued an optimization culture method for duck primary hepatocytes to explore AS in choline-deficient model. Methods: We performed an optimization culture method for duck primary hepatocytes with multi-step digestion procedure from Pekin duck embryos. Subsequently a NAFLD model was constructed with choline-free medium. RNA-seq and further analysis by rMATS were performed to identify AS events alterations in choline-deficency duck primary hepatocytes. Results: The results showed E13 (embryonic day 13) to E15 is suitable to obtain hepatocytes, and the viability reached over 95% by trypan blue exclusion assay. Primary hepatocyte retained their biological function as well identified by Periodic Acid-Schiff staining method and Glucose-6-phosphate dehydrogenase activity assay, respectively. Meanwhile, genes of alb and afp and specific protein of albumin were detected to verify cultured hepatocytes. Immunofluorescence was used to evaluate purity of hepatocytes, presenting up to 90%. On this base, choline-deficient model was constructed and displayed significantly increase of intracellular triglyceride and cholesterol as reported previously. Intriguingly, our data suggested that AS events in choline-deficient model were implicated in pivotal biological processes as an aberrant transcriptional regulator, of which 16 genes were involved in lipid metabolism and highly enriched in glycerophospholipid metabolism. Conclusion: An effective and rapid protocol for obtaining duck primary hepatocytes was established, by which our findings manifested choline deficiency could induce the accumulation of lipid and result in aberrant AS events in hepatocytes, providing a novel insight into various AS in the metabolism role of choline.