• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.74-78
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• 1998

Synthesis of novel 9-fluoroanthracyclines carrying L-fucose as a sugar component is described. Compound 3 containing a fluorine at the C-9 position was synthesized from an epoxide 2 and HF/Pyr (7 : 3). Bromination and hydrolysis of compound 3 resulted in synthesis of an aglycone, 9-fluoroanthracyclinone 6. The α-(1b) and β -anomers (1a) of the final product were obtained in high yields by a coupling reaction with the L-fucose.

• Korean journal of applied entomology
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• v.50 no.2
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• pp.107-113
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• 2011

Benzylideneacetone (BZA) is a compound derived from culture broth of an entomopathogenic bacterium, Xenorhabdus nematophila (Xn). Its immunosuppressive activity is caused by its inhibitory activity against eicosanoid biosynthesis. This BZA is being developed as an additive to enhance control efficacy of other commercial microbial insecticides. This study was focused on the enhancement of the immunosuppressive activity of BZA by generating its chemical derivatives toward decrease of its hydrophobicity. Two hydroxylated BZA and one sugar-conjugated BZA were chemically synthesized. All derivatives had the inhibitory activities of BZA against phospholipase $A_2$ ($PLA_2$) and phenoloxidase (PO) of the diamondback moth, Plutella xylostella, but BZA was the most potent. Mixtures of any BZA derivative with Bacillus thuringiensis (Bt) significantly increased pathogenicity of Bt. BZA also inhibited colony growth of four plant pathogenic fungi. However, BZA derivatives (especially the sugar-conjugated BZA) lost the antifungal activity. These results indicated that BZA and its derivatives inhibited catalytic activities of two immune-associated enzymes ($PLA_2$ and PO) of P. xylostella and enhanced Bt pathogenicity. We suggest its use to control plant pathogenic fungi.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.986-990
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• 2006

As key nucleoside intermediates for the preparation of cyclic adenosine diphosphate ribose (cADPR, 1) analogues, 8-alkyl-2' (or 3')-azido(or amino)-adenosine derivatives (16-19) were successfully prepared by alkylating selectively protected adenosine derivatives (12, 13) via Pd(0) catalyzed cross-coupling reaction with tetraalkyltin reagents, followed by the sugar modification of these 8-alkyl-adenosine derivatives according to our precedent procedure. Compared to other precedent procedures, our 8-alkylation methodology using selectively TBDMS-protected 8-alkyl adenosine derivatives as starting materials will be utilized very conveniently to prepare highly functionalized adenosine analogues, which will be serve as key intermediates for the cADPR.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.88-94
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• 2008

Two sugar biosynthetic cassette plasm ids were used to direct the biosynthesis of a deoxyaminosugar. The pOTBP1 plasmid containing TDP-glucose synthase (desIII), TDP-glucose-4,6-dehydratase (desIV), and glycosyltransferase (desVII/desVIII) was constructed and transformed into S. venezuelae YJ003, a strain in which the entire gene cluster of desosamine biosynthesis is deleted. The expression plasmid pOTBP3 containing 4-aminotransferase (gerB) and 3,5-epimerase (orf9) was transformed again into S. venezuelae YJ003-OTBP1 to obtain S. venezuelae YJ003-OTBP3 for the production of 4-amino-4,6-dideoxy-L-glucose derivatives. The crude extracts obtained from S. venezuelae ATCC 15439, S. venezuelae YJ003, and S. venezuelae YJ003-OTBP3 were further analyzed by TLC, bioassay, HPLC, ESI/MS, LC/MS, and MS/MS. The results of our study clearly shows that S. venezuelae YJ003-OTBP3 constructs other new hybrid macrolide derivatives including 4-amino-4,6-dideoxy-L-glycosylated YC-17 (3, [M+ $Na^+$] m/z=464.5), methymycin (4, m/z=480.5), novamethymycin (6, m/z=496.5), and pikromycin (5, m/z=536.5) from a 12-membered ring aglycon (10-deoxymethynolide, 1) and a 14-membered ring aglycon (narbonolide, 2). These results suggest a successful engineering of a deoxysugar pathway to generate novel hybrid macrolide derivatives, including deoxyaminosugar.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.630-634
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• 1997

A fluorescence tagging agent, FMOC-Cl (9-fluorenylmethyl chloroformate) was used for the determination of 1-amino-oligosaccharide intermediates generated from glycoproteins by peptide-N $(N-acetyl-{\beta}-D-glucosaminyl)$ asparagine amidase (N-Glycanase, PNGase F). The derivatives were separated on an Amido 80 column by HPLC using a gradient system with 25 to 51% aqueous acetonitrile and monitored by a fluorometric detector. The detection limit of FMOC-amino-oligosaccharides was $0.05{\sim}1.5$ pmol with fluorometric detection at 278 nm.

• Food Science and Preservation
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• v.15 no.5
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• pp.699-705
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• 2008

This study compared amino acids and effective components of Viola mandshurica produced in Korea with those of Chinese plants, as part of a study on nutritional andfunctional materials, to aid in the development of a valuable food. The contents of reducing sugar, free sugar, polyphenols, and soluble protein in the flowers of V. mandshurica were higher than in other fractions, being 10,485.11 mg%, 118.85 mg%, 1,259.26 mg%, and 23.67 mg%, respectively. Total flavonoid content of Chinese leaves was the highest at 2,370.75 mg%, followed by 1,844.43 mg% in Korean leaves. Free amino acids were highest in Korean leaves (5,345.21 mg%), followed by roots (4,692.24 mg%), flowers (3,807.87 mg%), and leaves of China plants (3,613.81 mg%). Arginine accounted for 55% of free amino acids in the roots, and all plant fractions contained more valine, aspartic acid, glutamic acid, alanine, and arginine, than other amino acids. The total content of amino acid derivatives was the highest (9,058.80 mg%) in Korean leaves. Especially, $\alpha$-aminoadipic acid constituted over 50% of total amino acid derivatives in all plant parts of V. mandshurica. When mineral contents were analyzed, leaves grown in China showed the highest content of 5,917.57 mg%, and the contents of K, Ca, and Mg were much greater than those of other minerals, together comprising over 95% of total mineral content in leaves and flowers from Korea.

• Journal of the Korean Society of Food Culture
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• v.9 no.2
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• pp.131-136
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• 1994

The ethylacetate extract of Lactuca dentata Makino showed 6 flavonoidal components as detected by ferric chloride solution. The flavonoidal constituent of Lactuca dentata Makino was isolated and purified by the series of column chromatography. The chemical structure of one of the flavonoidal component named as compound E was identified by UV, IR and NMR spectrometry. The melting point range of compound E was $249.5^{\circ}C-251^{\circ}C$. The UV and IR spectra of purified compound E, and its genin were measured with the various shifting agents. The results of UV analysis showed the free state of hydroxy group at 3rd and 4th carbon and binding of sugar at the 7th carbon of compound. The sugar bound to the compound E was identified as glucose by TLC. The IR spectrum showed the presense of hydroxy group, conjugated carbonyl group and aromatic group. The analysis of NMR spectrum was done to the purified compound and its derivatives. The chemical shifts against hydrogen atom, hydroxy group, and the moiety of luteolin were observed in the NMR spectrum along with their position and number as well as type of sugar bound. The isolated and purified compound was identified as $luteolin-7-0-{\beta}-D-glucoside$.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.431-436
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• 1990

The functional properties of novel sugar derivative sweeteners, fructo-oligosaccharide, maltitol, sorbitol and high maltose syrup(HMS) were examined for their humactant effect, lactic acid bacterial growth, Streptococcus mutants growth and relative sweetness compared to sucrose. Sorbitol exhibited remarkably high water activity reducing capacity, whereas fructo-oligosaccharide and maltitol showed the same level as sucrose. Maltitol showed distinct anti-bacterial(bacteriocidic) effect against Stc. mutants and most of lactic acid bacteria tested except for L. plantarum. The molar basis relative sweetness of sugar derivatives in comparison with 1%(w/w) level of sucrose were 0.69 for Neosugar(fructo-oligosaccharide), 0.21 for sorbitol, 0.50 for maltitol and 0.27 for HMS.

• Journal of Food Hygiene and Safety
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• v.26 no.1
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• pp.16-24
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• 2011

A method was established for the simultaneous determination of sugar alcohols, erythritol, xylitol, sorbitol, inositol, mannitol, maltitiol, lactitol and isomalt by High Performance Liquid Chromatography (HPLC). The sugar alcohols were converted into strong ultraviolet (UV)-absorbing derivatives with p-nitrobenzoyl chloride (PNBC). HPLC was performed on Imtakt Unison US-$C_18$ column, using acetonitrile: water (77:23) as a mobile phase and UV detection (260 nm). The calibration curves for all sugar alcohols tested were linear in the 10~200 mg/L range. The average recoveries of the sugar alcohols from three confectioneries spiked at 100 ppm of eight sugar alcohol standards ranged from 81.2 to 123.1% with relative standard deviations ranging fromo 0.2 to 4.9%. The limits of detection (LODs) were $0.5{\sim}8\;{\mu}g/L$ and the limits of quantification (LOQs) were $2{\sim}17\;{\mu}g/L$. Reproducibility of 8 sugar alcohols was 0.28~1.97 %RSD. The results of the analysis of confectioneries showed that 89 samples of 130 were detected and the sugar alcohols content of samples investigated varied between 0.4 and 693.7 g/kg. A method for the simultaneous determination of eight sugar alcohols will be used as basic data for control of sugar alcohols in confectioneries, and quality control in food manufacturing.

• Journal of Microbiology and Biotechnology
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• v.17 no.12
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• pp.1909-1921
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• 2007

Significant progress has recently been made concerning the engineering of deoxysugar biosynthesis. The biosynthetic gene clusters of several deoxysugars from various polyketides and aminoglycosides-producing microorganisms have been cloned and studied. This review introduces the biosynthetic pathways of several deoxysugars and the generation of novel hybrid macrolide antibiotics via the coexpression of deoxysugar biosynthetic gene cassettes and the substrate-flexible glycosyltransferases in a host organism as well as the production of TDP-deoxysugar derivatives via one-pot enzymatic reactions with the identified enzymes. These recent developments in the engineering of deoxysugars biosynthesis may pave the way to create novel secondary metabolites with potential biological activities.