A Novel Process for the Production of Clinical Dextran.

A new process for the production of clinical (or controlled size) dextran was developed. This process is simpler, cheaper and more economical than traditional methods. It involves the use of a mixed culture fermentation with a dextranase producing strain (Lipomyces starkeyi ATCC 74054) and a dextransucrase producing strain (Leuconostoc mesenteroides ATCC 10830). The new process produced 84% (w/w) of theoretical yield clinical dextran with an average polydispersity between 1.2 and 1.5. The mechanism of clinical dextran formation is the competitive production of acceptors from newly formed dextran molecules by dextranase. The acceptors compete for the existing glucosyl portion of sucrose, resulting in higher levels of smaller size dextran molecules. The maintenance of a proper balance of dextransucrase to dextranase is essential for the functioning of this process

Facile preparation of water soluble curcuminoids extracted from turmeric (Curcuma longa L.) powder by using steviol glucosides

AbstractCurcuminoids from rhizomes of Curcuma longa possess various biological activities. However, low aqueous solubility and consequent poor bioavailability of curcuminoids are major limitations to their use. In this study, curcuminoids extracted from turmeric powder using stevioside (Ste), rebaudioside A (RebA), or steviol glucosides (SG) were solubilized in water. The optimum extraction condition by Ste, RebA, or SG resulted in 11.3, 9.7, or 6.7mg/ml water soluble curcuminoids. Curcuminoids solubilized in water showed 80% stability at pH from 6.0 to 10.0 after 1week of storage at 25°C. The particle sizes of curcuminoids prepared with Ste, RebA, and SG were 110.8, 95.7, and 32.7nm, respectively. The water soluble turmeric extracts prepared with Ste, RebA, and SG showed the 2,2-diphenyl-1-picrylhydrazyl radical scavenging (SC50) activities of 127.6, 105.4, and 109.8μg/ml, and the inhibition activities (IC50) against NS2B-NS3pro from dengue virus type IV of 14.1, 24.0 and 15.3μg/ml, respectively

The effect of fermented buckwheat on producing L-carnitine enriched oyster mushroom

L-carnitine is biological compound which serves intake of long chain fatty acids into mitochondria. In market, L-carnitine is considered as nutritious supplements for weight-loss. L-carnitine is synthesized in human organ, but most of L-carnitine which human intakes are originated from meat based foods. Oyster mushroom (Pleurotus ostreatus), the second popular edible mushroom in the world, is the main source of L-carnitine after meat and pork. Recently, there were many efforts to study designer foods of which functional ingredients were increased. However most of studies were focused on dairy products. In this study, the fermented buckwheat by Rhizopus oligosporus that contained high L-carnitine contents were used to cultivate oyster mushroom. L-carnitine contents in oyster mushroom were quantified by LC-ESI-MS. Mushroom grown on buckwheat medium had 3.17 to 23.88% higher L-carnitine concentration than normal medium. The mushroom size was increased when 20% (w/w) of buckwheat was added to basal medium. The lightness of mushroom pileus (L*) significantly increased among all the treatments. These results demonstrate that buckwheat and fermented buckwheat is novel substrates to produce L-carnitine enriched functional mushroom.OAIID:RECH_ACHV_DSTSH_NO:A201702463RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A079459CITE_RATE:FILENAME:태경.pdfDEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/34dfad8a-5bc9-41cd-8160-c7846937fa22/linkCONFIRM:

Synthesis and characterization of novel astragalin galactosides using b-galactosidase from Bacillus circulans

OAIID:RECH_ACHV_DSTSH_NO:A201702462RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A079459CITE_RATE:FILENAME:송희.pdfDEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/f0c7ed28-3351-4830-b2b7-0684541b85e2/linkCONFIRM:

Enzymatic production of indigestible maltooligosaccharides using glucansucrases from Leuconostoc mesenteroides B-512FMCM and B-1355CF10

OAIID:RECH_ACHV_DSTSH_NO:A201702459RECH_ACHV_FG:RR00200003ADJUST_YN:EMP_ID:A079459CITE_RATE:FILENAME:동구.pdfDEPT_NM:국제농업기술학과EMAIL:[email protected]_YN:FILEURL:https://srnd.snu.ac.kr/eXrepEIR/fws/file/fe71fb5d-1d6e-4cb2-8b2b-28f93b1bca3c/linkCONFIRM:

Enzymatic synthesis of chlorogenic acid glucoside using dextransucrase and its physical and functional properties

Chlorogenic acid, a major polyphenol in edible plants, possesses strong antioxidant activity, anti-lipid peroxidation and anticancer effects. It used for industrial applications; however, this is limited by its instability to heat or light. In this study, we, for the first time synthesized chlorogenic acid glucoside (CHG) via transglycosylation using dextransucrase from Leuconostoc mesenteroides and sucrose. CHG was purified and its structure determined by nuclear magnetic resonance and matrix-associated laser desorption ionization–time-of-flight mass spectroscopy. The production yield of CHG was 44.0% or 141 mM, as determined by response surface methodology. CHG possessed a 65% increase in water solubility and a 2-fold browning resistance and it displayed stronger inhibition of lipid peroxidation and of colon cancer cell growth by MTT assay, compared to chlorogenic acid. Therefore, this study may expand the industrial applications of chlorogenic acid as water-soluble or browning resistant compound (CHG) through enzymatic glycosylation

Arylstibonic acids are potent and isoform-selective inhibitors of Cdc25a and Cdc25b phosphatases

Arylstibonates structurally resemble phosphotyrosine side chains in proteins and here we addressed the ability of such compounds to act as inhibitors of a panel of mammalian tyrosine and dual-specificity phosphatases. Two arylstibonates both possessing a carboxylate side chain were identified as potent inhibitors of the protein tyrosine phosphatase PTP-β. In addition, they inhibited the dual-specificity, cell cycle regulatory phosphatases Cdc25a and Cdc25b with sub-micromolar potency. However, the Cdc25c phosphatase was not affected demonstrating that arylstibonates may be viable leads from which to develop isoform specific Cdc25 inhibitors

Parallelized computational 3D video microscopy of freely moving organisms at multiple gigapixels per second

To study the behavior of freely moving model organisms such as zebrafish (Danio rerio) and fruit flies (Drosophila) across multiple spatial scales, it would be ideal to use a light microscope that can resolve 3D information over a wide field of view (FOV) at high speed and high spatial resolution. However, it is challenging to design an optical instrument to achieve all of these properties simultaneously. Existing techniques for large-FOV microscopic imaging and for 3D image measurement typically require many sequential image snapshots, thus compromising speed and throughput. Here, we present 3D-RAPID, a computational microscope based on a synchronized array of 54 cameras that can capture high-speed 3D topographic videos over a 135-cm^2 area, achieving up to 230 frames per second at throughputs exceeding 5 gigapixels (GPs) per second. 3D-RAPID features a 3D reconstruction algorithm that, for each synchronized temporal snapshot, simultaneously fuses all 54 images seamlessly into a globally-consistent composite that includes a coregistered 3D height map. The self-supervised 3D reconstruction algorithm itself trains a spatiotemporally-compressed convolutional neural network (CNN) that maps raw photometric images to 3D topography, using stereo overlap redundancy and ray-propagation physics as the only supervision mechanism. As a result, our end-to-end 3D reconstruction algorithm is robust to generalization errors and scales to arbitrarily long videos from arbitrarily sized camera arrays. The scalable hardware and software design of 3D-RAPID addresses a longstanding problem in the field of behavioral imaging, enabling parallelized 3D observation of large collections of freely moving organisms at high spatiotemporal throughputs, which we demonstrate in ants (Pogonomyrmex barbatus), fruit flies, and zebrafish larvae

WISDOM-II: Screening against multiple targets implicated in malaria using computational grid infrastructures

<p>Abstract</p> <p>Background</p> <p>Despite continuous efforts of the international community to reduce the impact of malaria on developing countries, no significant progress has been made in the recent years and the discovery of new drugs is more than ever needed. Out of the many proteins involved in the metabolic activities of the <it>Plasmodium </it>parasite, some are promising targets to carry out rational drug discovery.</p> <p>Motivation</p> <p>Recent years have witnessed the emergence of grids, which are highly distributed computing infrastructures particularly well fitted for embarrassingly parallel computations like docking. In 2005, a first attempt at using grids for large-scale virtual screening focused on plasmepsins and ended up in the identification of previously unknown scaffolds, which were confirmed in vitro to be active plasmepsin inhibitors. Following this success, a second deployment took place in the fall of 2006 focussing on one well known target, dihydrofolate reductase (DHFR), and on a new promising one, glutathione-S-transferase.</p> <p>Methods</p> <p>In silico drug design, especially vHTS is a widely and well-accepted technology in lead identification and lead optimization. This approach, therefore builds, upon the progress made in computational chemistry to achieve more accurate <it>in silico </it>docking and in information technology to design and operate large scale grid infrastructures.</p> <p>Results</p> <p>On the computational side, a sustained infrastructure has been developed: docking at large scale, using different strategies in result analysis, storing of the results on the fly into MySQL databases and application of molecular dynamics refinement are MM-PBSA and MM-GBSA rescoring. The modeling results obtained are very promising. Based on the modeling results, <it>In vitro </it>results are underway for all the targets against which screening is performed.</p> <p>Conclusion</p> <p>The current paper describes the rational drug discovery activity at large scale, especially molecular docking using FlexX software on computational grids in finding hits against three different targets (PfGST, PfDHFR, PvDHFR (wild type and mutant forms) implicated in malaria. Grid-enabled virtual screening approach is proposed to produce focus compound libraries for other biological targets relevant to fight the infectious diseases of the developing world.</p

Determination of sin2 θeff w using jet charge measurements in hadronic Z decays

The electroweak mixing angle is determined with high precision from measurements of the mean difference between forward and backward hemisphere charges in hadronic decays of the Z. A data sample of 2.5 million hadronic Z decays recorded over the period 1990 to 1994 in the ALEPH detector at LEP is used. The mean charge separation between event hemispheres containing the original quark and antiquark is measured for bb̄ and cc̄ events in subsamples selected by their long lifetimes or using fast D*'s. The corresponding average charge separation for light quarks is measured in an inclusive sample from the anticorrelation between charges of opposite hemispheres and agrees with predictions of hadronisation models with a precision of 2%. It is shown that differences between light quark charge separations and the measured average can be determined using hadronisation models, with systematic uncertainties constrained by measurements of inclusive production of kaons, protons and A's. The separations are used to measure the electroweak mixing angle precisely as sin2 θeff w = 0.2322 ± 0.0008(exp. stat.) ±0.0007(exp. syst.) ± 0.0008(sep.). The first two errors are due to purely experimental sources whereas the third stems from uncertainties in the quark charge separations