Application of 13C-labeling and 13C–13C COSY NMR experiments in the structure determination of a microbial natural product

권윤,박성혁,신종헌,오동찬 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.8

The elucidation of the structures of complexnatural products bearing many quaternary carbons remainschallenging, even in this advanced spectroscopic era. 13C–13C COSY NMR spectroscopy shows direct couplingsbetween 13C and 13C, which comprise the backbone of anatural product. Thus, this type of experiment is particularlyuseful for natural products bearing consecutive quaternarycarbons. However, the low sensitivity of 13C-basedNMR experiments, due to the low natural abundance of the13C nucleus, is problematic when applying these techniques. Our efforts in the 13C labeling of a microbial naturalproduct, cyclopiazonic acid (1), by feeding 13C-labeledglucose to the fungal culture, enabled us to acquire13C–13C COSY NMR spectra on a milligram scale thatclearly show the carbon backbone of the compound. This isthe first application of 13C–13C COSY NMR experimentsfor a natural product. The results suggest that 13C–13CCOSY NMR spectroscopy can be routinely used for thestructure determination of microbial natural products by13C-enrichment of a compound with 13C-glucose.

Evaluation of carbon dioxide emission factor from urea during rice cropping season: A case study in Korean paddy soil

Kim, G.W.,Jeong, S.T.,Kim, G.Y.,Kim, P.J.,Kim, S.Y. Pergamon Press ; Elsevier [distribution] 2016 Atmospheric environment Vol.139 No.-

<P>Fertilization with urea can lead to a loss of carbon dioxide (CO2) that was fixed during the industrial production process. The extent of atmospheric CO2 removal from urea manufacturing was estimated by the Industrial Processes and Product Use sector (IPPU sector). On its basis, the Intergovernmental Panel on Climate Change (IPCC) has proposed a value of 0.2 Mg C per Mg urea (available in 2006 revised IPCC guidelines for greenhouse gas inventories), which is the mass fractions of C in urea, as the CO2 emission coefficient from urea for the agricultural sector. Notably, due to the possibility of bicarbonate leaching to waters, all C in urea might not get released as CO2 to the atmosphere. Hence, in order to provide an accurate value of the CO2 emission coefficient from applied urea in the rice ecosystem, the CO2 emission factors were characterized under different levels of C-13-urea applied paddy field in the current study. The total CO2 fluxes and rice grain yields increased significantly with increasing urea application (110 -130 kg N ha(-1)) and thereafter, decreased. However, with increasing C-13-urea application, a significant and proportional increase of the (CO2)-C-13-C emissions from C-13-urea was also observed. From the relationships between urea application levels and (CO2)-C-13-C fluxes from C-13-urea, the CO2-C emission factor from urea was estimated to range between 0.0143 and 0.0156 Mg C per Mg urea. Thus, the CO2-C emission factor of this study is less than that of the value proposed by IPCC. Therefore, for the first time, we propose to revise the current IPCC guideline value of CO2-C emission factor from urea as 0.0143-0.0156 Mg C per Mg urea for Korean paddy soils. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Evaluation of the carbon dioxide (CO₂) emission factor from lime applied in temperate upland soil

Cho, Song Rae,Jeong, Seung Tak,Kim, Gun Yeob,Lee, Jeong Gu,Kim, Pil Joo,Kim, Gil Won Elsevier 2019 Geoderma Vol.337 No.-

<P><B>Abstract</B></P> <P>Agricultural liming materials are broadly utilized in the world to ameliorate soil acidity. Crushed limestone (CaCO<SUB>3</SUB>) and dolomite (MgCO<SUB>3</SUB>·CaCO<SUB>3</SUB>) are most common liming materials. The CO<SUB>2</SUB> emission coefficient was proposed as 0.12 Mg C per Mg for CaCO<SUB>3</SUB> by the Intergovernmental Panel on Climate Change (IPCC), which indicates that 100% of C in CaCO<SUB>3</SUB> is eventually released to the atmosphere in the form of CO<SUB>2</SUB>. However, this assumption appears unlikely based on current knowledge of the very low solubility of CaCO<SUB>3</SUB> and carbonate transport through soil. To develop the direct CO<SUB>2</SUB> emission factor from the C-containing liming materials applied in moderately acidic soil, CaCO<SUB>3</SUB> was applied in a typical temperate upland soil at different levels (0–2 Mg ha<SUP>−1</SUP> yr<SUP>−1</SUP>), and the CO<SUB>2</SUB> emission rates were determined using the closed chamber method for two years. The direct CO<SUB>2</SUB> emission factor from CaCO<SUB>3</SUB> was estimated using <SUP>13</SUP>CO<SUB>2</SUB> fluxes from <SUP>13</SUP>C-CaCO<SUB>3</SUB> applied soils. Approximately 0.026 Mg C per Mg of CaCO<SUB>3</SUB> was emitted as CO<SUB>2</SUB> from CaCO<SUB>3</SUB> in cropping lands. This value was much lower than the IPCC default value (0.12 Mg C per Mg of CaCO<SUB>3</SUB>). The current CO<SUB>2</SUB> emission coefficient was comparable with the United States Environmental Protection Agency (EPA) emission factor (0.046 Mg C per Mg of CaCO<SUB>3</SUB>) from the agricultural field. If the EPA emission factor from the ocean (0.013 Mg C per Mg of CaCO<SUB>3</SUB>) is added to the currently developed CO<SUB>2</SUB> emission factor of the inner agricultural field, the total CO<SUB>2</SUB> emission factor from lime may be close to 0.039 Mg C per Mg of CaCO<SUB>3</SUB> in the selected upland soil. Therefore, we propose that the current IPCC guideline value of the CO<SUB>2</SUB> emission factor from lime should be revised as 0.039 Mg C per Mg of CaCO<SUB>3</SUB> for Korean upland soils.</P> <P><B>Highlights</B></P> <P> <UL> <LI> IPCC proposed 0.12 Mg CO<SUB>2</SUB>-C per Mg CaCO<SUB>3</SUB> as the CO<SUB>2</SUB> emission factor from CaCO<SUB>3</SUB> in soil. </LI> <LI> 0.026 Mg CO<SUB>2</SUB>-C per Mg CaCO<SUB>3</SUB> was emitted from CaCO<SUB>3</SUB> during maize cultivation. </LI> <LI> EPA estimated 0.013 Mg CO<SUB>2</SUB>-C per Mg CaCO<SUB>3</SUB> of CO<SUB>2</SUB> emission factor released from agricultural field. </LI> <LI> CO<SUB>2</SUB> emission factor of CaCO<SUB>3</SUB> should be revised with 0.039 Mg CO<SUB>2</SUB>-C per Mg CaCO<SUB>3</SUB> in Korean upland soil. </LI> </UL> </P>

Potential Role of Protein Kinase C on the Differentiation of Erythroid Progenitor Cells

Lee, Sang-Jun,Cho, In-Koo,Huh, In-Hoe,Yoon, Ki-Yom,Ann, Hyung-Soo The Pharmaceutical Society of Korea 1995 Archives of Pharmacal Research Vol.18 No.2

The effect of protein kinase C inhibitors, sturosporine and 1-(5-isoquinolinyl sulfonyl)-2-methyl piperazine(H7) on in vitro differentiation of erythroid progenitor cells which were isolated from spleens of mice infected with the anemia-inducing strain of Friend virus were examined. Erythropoietin-mediated differentitation of erythroid progenitor cells, as determined by the incorporation of $^{59}Fe$ into protoporphyrin, was inhibited by staurosporine and H7 in a concentration -dependent manner. Scatchard analysis of the $^3H-phorbol-12$, 13-dibutyrate binding to erythroid progenitor cells revealed that at the high affinity sites the dissociation constant was 22nM and the maximum number of $^3H-phorbol-12$, 13-dibutyrate binding to erythroid progenitor cells revealed that at the high affinity sites the dissociation constant was 22nM and the maximum number of $^3H-phorbol-12$, 13-dibutyrate binding sites per cell was approximately $3.7\times10^5$. Cytosonic protein kinase C was isolated from erthroid progenitor cells and then purified by sequential column chromatogrphy. Two isoforms of protein kinase C were found. Photoaffinity labeling of the purified protein kinase C samples with $^3H-phorbol-12$12-myristate 13-acetate followed by analysis of SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and autofluorography showed radiolabeled 82-KDa pepticles. Rediolabeling of the 82-KDa peptides with $^3H-phorbol-12$myristate 13-acete was almost completely blocked by excess unlabeled phorbol 12-myristate 13-acetate was almost 12-muristate 13-acetate-promoted phosphorylation with the puyrified protein kinase C samples showed that the phosphorylation of 82-KDa peptides was increased as the concentration of phorbol 12-myristate 13-acetate was increased from $10^{-8}M{\;}to{\;}10^{-4}$M. In light of the findings that erythroid progenitor cells possessed an abundance of protein kinase C and that stauroporine and H7 inhibited erythroid differentiation, it seemed likely that protein kinase C would play a role in the erythroid progenitor cell development.

The Effect of 13c and 15n-Labelled Green Manures on the Dynamic Changes of the Soil Microbial Biomass C and N

Xi Xiangyin,Geng Sainan,Wang Shufeng,Xu Ying,Liu Meiyu 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Central energy metabolism remains robust in acute steatotic hepatocytes challenged by a high free fatty acid Load

( Jens Niklas ),( Anne Bonin ),( Stefanie Mangin ),( Joachim Bucher ),( Stephanie Kopacz ),( Madlen Matz-soja ),( Carlo Thiel ),( Rolf Gebhardt ),( Ute Hofmann ),( Klaus Mauch ) 생화학분자생물학회 2012 BMB Reports Vol.45 No.7

Overnutrition is one of the major causes of non-alcoholic fatty liver disease (NAFLD). NAFLD is characterized by an accumulation of lipids (triglycerides) in hepatocytes and is often accompanied by high plasma levels of free fatty acids (FFA). In this study, we compared the energy metabolism in acute steatotic and non-steatotic primary mouse hepatocytes. Acute steatosis was induced by pre-incubation with high concentrations of oleate and palmitate. Labeling experiments were conducted using [U-13C5,U-15N2] glutamine. Metabolite concentrations and mass isotopomer distributions of intracellular metabolites were measured and applied for metabolic flux estimation using transient 13C metabolic flux analysis. FFAs were efficiently taken up and almost completely incorporated into triglycerides (TAGs). In spite of high FFA uptake rates and the high synthesis rate of TAGs, central energy metabolism was not significantly changed in acute steatotic cells. Fatty acid β-oxidation does not significantly contribute to the detoxification of FFAs under the applied conditions. [BMB Reports 2012; 45(7): 396-401]

Incorporating metabolic flux ratios into constraint-based flux analysis by using artificial metabolites and converging ratio determinants

Choi, Hyung Seok,Kim, Tae Yong,Lee, Dong-Yup,Lee, Sang Yup Elsevier Science Publishers 2007 Journal of biotechnology Vol.129 No.4

<P><B>Abstract</B></P><P>One of the well-established approaches for the quantitative characterization of large-scale underdetermined metabolic network is constraint-based flux analysis, which quantifies intracellular metabolic fluxes to characterize the metabolic status. The system is typically underdetermined, and thus usually is solved by linear programming with the measured external fluxes as constraints. Thus, the intracellular flux distribution calculated may not represent the true values. <SUP>13</SUP>C-constrained flux analysis allows more accurate determination of internal fluxes, but is currently limited to relatively small metabolic networks due to the requirement of complicated mathematical formulation and limited parameters available. Here, we report a strategy of employing such partial information obtained from the <SUP>13</SUP>C-labeling experiments as additional constraints during the constraint-based flux analysis. A new methodology employing artificial metabolites and converging ratio determinants (CRDs) was developed for improving constraint-based flux analysis. The CRDs were determined based on the metabolic flux ratios obtained from <SUP>13</SUP>C-labeling experiments, and were incorporated into the mass balance equations for the artificial metabolites. These new mass balance equations were used as additional constraints during the constraint-based flux analysis with genome-scale <I>E. coli</I> metabolic model, which allowed more accurate determination of intracellular metabolic fluxes.</P>

Application of 13C MFA for microbial GABA production

Dae-kyun IM,Min-Kyu OH 한국생물공학회 2018 한국생물공학회 학술대회 Vol.2018 No.10

The Fate of Soybean Photosynthetic Carbon Varies in Mollisols Differing in Organic Carbon

Jian Jin,Guanghua Wang,Judong Liu,Zhenhua Yu,Xiaobing Liu,Stephen J Herbert 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Soil Disturbance Effects on Plant Residue Decay in Canadian Agricultural Soils

Benjamin Ellert,Ed Gregorich,Henry Janzen,Bobbi Helgason 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6