• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.37-41
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• 2004

A new tridentate ligand incorporating a monoxime and thiosemi-carbozone moieties has been synthesized. Its copper(II), nickel(II) and palladium(II) complexes have been prepared and characteirzed by physical and spectral methods. Elemental analyses and spectroscopic data of the metal complexes are consistent with the formation of a mononuclear copper(II) complex and binuclear complex with both nickel(II) and palladium(II). In the copper(II) complex the fourth coordination site is occupied by nitrate ion. In the binculear complexes the fourth coordination site is occupied by the deprotonated oxime oxygen of the ligand coordinated to the other metal.

• Journal of Microbiology and Biotechnology
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• v.10 no.5
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• pp.606-611
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• 2000

Dimorphic yeast Candida albicans reversibly switches between the form of yeast and hyphae depending on external conditions. We investigated possible roles of the myosin family in the growth and dimorphic switches of C. albicans with a general myosin ATPase inhibitor, 2,3-butanedione-2-monoxime (BDM). Transition to hyphae as well as proliferation by budding was completely inhibited by BDM at 16 mM. Presence of 16 mM BDM did not affect hyphae-to-bud transition but it blocked budding. The effects of BDM on yeast growth and dimorphic switches were reversible. More than 70% of the BDM-treated cells demonstrated defects in the amount and the polarized localization of F-actin as well as in the shape and migration of the nucleus, suggesting that myosin activities are needed in these cellular processes of C. albicans.

• Journal of Technologic Dentistry
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• v.26 no.1
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• pp.49-58
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• 2004

Two diketones, 1-phenyl-1,2-propanedione(PD) and 2,3-butanedione (BD) were investigated as new visible light photosensitizers for a dental resin composite of bis-GMA in order to improve photopolymerization effect. And the photopolymerization efficiency of mixed photosensitizers, PD-CQ and DA-CQ, was studied. Photopolymerization effect of photosensitizers were compared with that of camphorquinone(CQ), the most widely used photosensitizer. The photopolymerization efficiency of bis-GMA containing the photosensitizer increased with irradiation time. The increase was in the order: BD < CQ < PD. The photopolymerization efficiency of this mixture was not so efficient as CQ or PD.

• Bulletin of the Korean Chemical Society
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• v.24 no.12
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• pp.1799-1804
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• 2003

Acetolatate synthase(ALS) catalyzes the first common step in the biosynthesis of valine, leucine, isoleucine in plants and microorganisms. ALS is the target of several classes of herbicides, including the sulfonylureas, the imidazolinones, and the triazolopyrimidines. To elucidate the roles of arginine residues in tobacco ALS, chemical modification and site-directed mutagenesis were performed. Recombinant tobacco ALS was expressed in E. coli and purified to homogeneity. The ALS was inactivated by arginine specific reagents, phenylglyoxal and 2,3-butanedione. The rate of inactivation was a function of the concentration of modifier. The inactivation by butanedione was enhanced by borate, and the inactivation was reversible on removal of excess butanedione and borate. The substrate pyruvate and competitive inhibitors fluoropyruvate and phenylpyruvate protected the enzyme against inactivation by both modifiers. The mutation of well-conserved Arg198 of the ALS by Gln abolished the enzymatic activity as well as the binding affinity for cofactor FAD. However, the mutation of R198K did not affect significantly the binding of FAD to the enzyme. Taken together, the results imply that Arg198 is essential for the catalytic activity of the ALS and involved in the binding of FAD, and that the positive charge of the Arg is crucial for the interaction with negatively charged FAD.

• Bulletin of the Korean Chemical Society
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• v.14 no.2
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• pp.179-183
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• 1993

Template condensation of ${\alpha}$-diketones such as 2,3-butanedione or benzil with diaminoalkanes such as 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,8-diaminooctane or 1,12-diaminododecane in the presence of Cr(III) results in the formation of complexes of the type $[CrI,X_2]X$ (where L = tetraazamacrocycle having 12 to 32-membered ring and $X={NO_3}^- or Cl^-).$ The complexes have been characterized by elemental analyses, magnetic measurements and IR and diffuse reflectance spectra.

• Food Science and Preservation
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• v.13 no.2
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• pp.269-272
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• 2006

Aroma compounds in chungkukjang with Astragalus membranaceus (Hwangki) were extracted by the simultaneous distillation and extraction (SDE), headspace and solid phase microextraction (SPME), and aroma compounds obtained by this method were identified with GC-MS. Thirty compounds were identified, including six ketones, eight alcohols, three heterocyclic compounds, three aldehydes, five hydrocarbones and five other compounds. Major aroma compounds were identified as 3-hydroxy-2-butanone, 2-furanmethanol, 2-methoxy-4-vinylphenol, and 4-vinylphenol in SDE, 2,3-butanedione, 3-hydroxy-2-butanone, ethanol, 2,6-dimethyl pyrazine and acetic acid in headspace and acetone, ethanol, 2,5-dimethyl pyrazine, tetramethyl pyrazine and acetic acid in SPME. The content of pyrazines identified in headspace and SPME methods was higher than that of SDE method, and the content of pyrazines containing 2,5-dimethyl pyrazine, 2,6-dimethyl pyrazine and tetramethyl pyrazine in chungkukjang was higher than that of Hwangki chungkukjang.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.441-447
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• 1999

Changes in flavor characteristics of roasted coffee in 6 package models during storage were investigated by GC/MS analysis and sensory evaluation to establish the criteria of the shelf-life of the roasted coffee in three flavor quality-'fresh', 'satisfying' and 'minimally acceptable' levels. In direct headspace method of GC/MS, 47 volatile compounds were analyzed and the light volatile compounds were reduced sharply at initial stage of storage and faster in the package with air. The correlation between % retention of 2,3-butanedione and overall aroma of roasted coffee showed good linear-relation, of which correlation coefficient (R) were from 0.999 to 0.904 depending on package models, indicating that 2,3-butanedione would be an index chemical for evaluating the freshness of roasted coffee. In sensory evaluation of 6 package models during storage, roasted whole beans (RB) and roasted and ground (RG) coffee in air-package were preserved in 'fresh quality' for $0.5{\sim}1$ week, 'satisfying quality' for $2{\sim}3$ weeks and 'minimally acceptable quality' for 12 weeks, while roasted whole beans in valve-package and roasted and ground coffees in vacuum-package, nitrogen-package and oxygen absorbent-package were preserved in 'fresh quality' for $2{\sim}4$ weeks, 'satisfying quality' for $12{\sim}24$ weeks and 'minimally acceptable quality' for 52 weeks. The oxygen absorbent-package was slightly less effective than other three methods.

• Analytical Science and Technology
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• v.25 no.6
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• pp.447-459
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• 2012

In this study, the emission characteristics of volatile and odorant species released from salted meat product (Spam) was investigated as a function of time. Gas samples released from Spam samples were analyzed for volatile organic compounds (VOC) and sulfur compounds (RSC) at five different times for the elapsed (E) days of 0, 1, 3, 6, and 9 (E-0 to E-9) by GC/MS and GC/PFPD system, respectively. Results indicated that reduced sulfur, aldehyde, and ketone groups were the dominant odorants. Especially, hydrogen sulfide was the predominant in concentration and odor activity value (OAV) during the fresh stage. Its concentration was 1465 ${\mu}g/m^3$ (60.0% of the total mass) in E-0 and 455 ${\mu}g/m^3$ (28.0%) in E-1, while its OAV was 19.4 (78.3%: E-0) and 6.02 (41.7%: E-1). On the other hand, the concentration of acetone showed the maximum values in the decaying stage (E-3: 451 (43.2%), E-6: 369 (64.2%), and E-9: 1150 ${\mu}g/m^3$ (70.2%)). Furthermore, the concentration of 2,3-butanedione was also detected considerably from decaying sample (E-3: 17.6 (1.68%), E-6: 16.1 (2.80%), and E-9: 179 ${\mu}g/m^3$ (10.9%)). However, OAV of acetone was insignificant (<0.01%) in the decaying stage, while that of 2,3-butanedione was relatively high in the range of 1.14-11.6 (14.5-76.2% of ${\Sigma}OAV$). It thus confirmed that the major odorant groups generated from Spam samples changed with the progress of decay such as sulfur (fresh stage), aldehyde (intermediate stage), and ketone compounds (decaying stage).

• Journal of Photoscience
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• v.12 no.2
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• pp.109-111
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• 2005

It was found that 1,4-diketones such as 1,4-diphenyl-l,4-butanediones containing N,N-dimethylaminophenyl (pDPB) and N,N-dimethylaminonaphthyl (nDPB) at C2 are converted into 3-(4-dimethylaminoaryl)-1-phenylpropan-lones (pPPA and nPPA) by treatment with $Ca(OH)_2$ in methanol, which was easily oxidized to enone, i.e., 3-(4-dimethylaminophenyl)-l-phenylpropenones (pPPE and nPPE), when treated with 2,3-dichloro-5,6-dicyano-l,4-benzoquinone (DDQ) in dichloromethane.

• Food Science and Preservation
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• v.13 no.4
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• pp.483-489
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• 2006

Considering the development of fusion ingredients rom red ginseng and Cheonggukjang (soybean-fermented food), their commercial powders were evaluated in their Hunter's colors, volatile compounds, and sensory properties depending on manufacturing companies and mixing ratio of both powdered products. Hunters L, a and b values of red ginseng powders were $75.56\sim85.50,\;1.90\sim6.30,\;and\;23.29\sim35.08$, respectively, while those of Cheonggukjang powders were $64.96\sim71.69,\;4.64\sim8.30,\;and\;30.45\sim36.50$, respectively. Volatile compounds were mainly composed of hexanal, $\beta-pinene$, methyl benzene, 3,5-methyl propyl nonane, 2-propanone, decane, and 2,8-dimethyl undecane in red ginseng samples, and of 2,3-butanedione, decane, 2,2,7,7-tetramethyl octane, and 3-methyl butanal in Cheonggukjang samples. Total volatiles of the mixed samples decreased as ginseng decreased and Cheonggukjang increased. The mixed sample of both red ginseng and cheonggukjang in same amounts was the highest in its sensory acceptability, which was composed in the order of 2-propanone, 2-butanone, pentane, hexanal and 3-methyl butanal. The above results indicate that red ginseng and Cheonggukjang showed a potential as fusion ingredient for preparing new functional produce through further processing.