• Bulletin of the Korean Chemical Society
• /
• v.23 no.1
• /
• pp.21-22
• /
• 2002

• KSBB Journal
• /
• v.21 no.1 s.96
• /
• pp.54-58
• /
• 2006

The purpose of this study is to search the characteristics of PVA degrading enzymes which were obtained from Microbacterium barkeri KCCM 10507 and Paenibacillus amylolyticus KCCM 10508, respectively. As a result of the PVA degrading test using crude enzymes, the activity of SAO (secondary alcohol oxidase) was maximized after 2 or 3 days from start of the test, while the activity of BDH (${\beta}$-diketone hydrolase) was gradually increased during the test. Activities of them were maintained in the presence of PVA, but as PVA was gradually degraded, their activity was decreased. PVA was inoculated again into the media, their activity was revealed. This result indicated that above two different enzymes were closely connected with PVA degradation and PVA was degraded by activity of SAO and BDH. Maximum activity of them was 1.5-1.8 unit for SAO and 1.5-2.0 unit for BDH under $35^{\circ}C$ and pH 7.8-8.8, respectively.

• Journal of Photoscience
• /
• v.7 no.3
• /
• pp.111-114
• /
• 2000

Irradiation of 1,3-cyclohexanedione and p-benzoquinone in methanol gave 3-methoxycyclohex-2-en-1-one. Allyl derivative of the 1,3-diketone was prepared as enol from and irradiated in methanol in the presence of p-benzoquinone to give the same type of photoproduct, i.e., 2-allyl-3-methoxycyclohex-2-en-1-one. Allyldibenzoylmethane was synthesized and irradiated with p-benzoauinone in methanol but no remarkable amount of photoproduct was obtained.

• Journal of Photoscience
• /
• v.11 no.3
• /
• pp.129-132
• /
• 2004

Photochemically stable dibenzoylmethane and curcumin were cleaved dramatically when they were irradiated in the presence of N,N-dimethylaniline in methanol with 300 nm UV light. Several products such as benzil, secondary product derived from 1,4-diphenyl-1,4-butanedione, and unidentified compound were observed from the photoreactions of dibenzoylmethane with N,N-dimethylaniline. It was also found that one of the primary fragments produced by irradiation of curcumin in methanol were coupled with N,N-dimethylaniline to give a new enone compound, i.e., 1-(4-dimethylaminophenyl)-4-(4-hydroxy-3-methoxyphenyl)-but-3-en-2-one, as the major product.

• Analytical Science and Technology
• /
• v.17 no.4
• /
• pp.337-346
• /
• 2004

7-keto-dehydroepiandrosterone-acetate (7-keto-DHEA-acetate) is an anabolic steroids, and we studied basically to the metabolites of it after human dosing. We tested the matrix effect from human urine to detect the 7-keto-DHEA-acetate. And LC/ESI/MS and GC/MSD was used to detect the metabolites in dosed urine. We found the some unknown compound from dosed urine (M1, M2, M3, M4 and M5), and from these results, we supposed that these compounds have the more than 3 hydroxyl and/or ketone group. Metabolite M1 was supposed that molecular weight is 302 and 3-,17-diketone and 7-hydroxyl compound (7-OH-androstendione). Metabolite M2 was supposed that the molecular weight was same to M1 and 7-,17-diketone and 3-hydroxyl compound (7-keto-DHEA).

• Bulletin of the Korean Chemical Society
• /
• v.17 no.11
• /
• pp.1023-1031
• /
• 1996

A new synthetic route for the lanthanum β-diketonate compounds via in-situ formed lanthanum alkyl complexes was developed in the process for the development of suitable MOCVD (metal-organic chemical vapor deposition) precursors of PLT, one of the promising material for the ferroelectric film. A series of lanthanum β-diketonate compounds were successfully synthesized by this method. This new method is found to have some merits; versatile method for almost every β-diketone, β-hydroxyketone, and β-hydroxyaldehyde, short reaction time, easy purification for high purity, moderate to high yield, and easy access to anhydrous compounds. In some cases, anhydrous oligomeric products fail to show the higher volatility. On the other hand, some lanthanum β-diketonates with aromatic groups such as La(1,3-biphenyl-l,3-propandione)3 are found to have favorable properties for a precursor of lanthanum oxide, one of major components of PLT, such as low melting point, and much higher decomposition temperature. A plausible pyrolysis mechanism is proposed by the TGA, where consecutive dissociation of R, CO, CH, C, and O fragments occurs.

• Journal of the Korean Chemical Society
• /
• v.18 no.6
• /
• pp.437-442
• /
• 1974

Pentacyclo ($5,3,0,0^{2,5},06{3,9},0^{4,8})-decane-6,10-dione was synthesized from the cyclopentanone in good overall yield(60%). Cyclopentanone ethylene ketal(Ⅰ) was brominated with pyridinium bromide perbromide, and the brominated ketal(Ⅱ) was converted to the dimer of cyclopentadienone ethylene ketal(Ⅲ). The ethylene ketal(Ⅲ) was again converted to the dicyclopentadiene-1,8-dione(Ⅳ). Finally, the pentacyclo ($5,3,0,0^{2,5},06{3,9},0^{4,8})-decane-6,10-dione(Ⅴ) was synthesized from the dicyclopentadilene-1,8-dione(Ⅳ) by photochemical cyclization.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.12
• /
• pp.3632-3638
• /
• 2010

2-Iminopyrimidines (1a-e) and 2-thioxopyrimidine (2) were synthesized using the Biginelli three component cyclocondensation reaction of an appropriate $\beta$-diketone, arylaldehyde, and guanidine (for 1a-e) or thiourea (for 2). The electrochemical properties of the novel systems were investigated by CV and DPV. Moreover, B3LYP/6-31G(d,p) method was applied to the present structures in order to gather some structural and physicochemical data.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.4
• /
• pp.1221-1227
• /
• 2011

Ethyl pyruvate (EP) is known as a scavenger of reactive oxygen species (ROS) in the body through its role in the donation of diketone groups to metals to form an EP-metal complex. In order to develop a method for the quantification of EP in biological media, a sensitive and specific, high-performance liquid chromatographyelectrospray ionization-mass spectrometry (HPLC-ESI/MS) method is used to determine the EP-alkali metal ion binding species. The analyte was separated on a ZORBOX SB-C8 ($3.5{\mu}m$, $30mm{\times}2.1mm$ I.D.) column and analyzed in selected ion monitoring (SIM) mode with a positive ESI interface using the m/z 255 $[2M + Na]^+$ ion. The method was validated over the concentration range of $0.5-60.0\;{\mu}g$/mL under 1/9 (v/v) of acetonitrile/methanol solvent system with flow rate 0.05 mL/min. The limit of quantification (LOQ) was $0.5{\mu}g$/mL.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.7
• /
• pp.637-642
• /
• 1996

Preparation and properties of potential CVD (Chemical Vapor Deposition) precursors for the TiO2, a major component of the perovskite materials such as PT, PLT, PZT, and PLZT were investigated. Reactions between β-diketones and TiMe3, formed in situ failed to produce stable Ti(β-diketonate)3 complexes but a stable purple solid, characterized as (OTi(BPP)2)2 (BPP=1,3-biphenyl-1,3-propanedione) was obtained when BPP was used. Several new Ti(Oi-Pr)2(β-diketonate)2 complexes with aromatic or ring substituents were synthesized by the substitution reaction of Ti(OiPr)4by β-diketones and characterized with 1H NMR, IR, ICP, and TGA. Solid complexes such as Ti(Oi-Pr)2(BAC)2 (BAC=1.-phenyl-2,4-pentanedione), Ti(Oi-Pr)2(BPP)2, Ti(Oi-Pr)2(1-HAN)2 (1-HAN=2-hydroxy-1-acetonaphthone), Ti(Oi-Pr)2(2-HAN)2 (2-HAN=1-hydroxy-2-acetonaphthone), Ti(Oi-Pr)2(ACCP)2 (ACCP=2-acetylcyclopentanone), and Ti(Oi-Pr)2(HBP)2 (HBP=2-hydroxybenzophenone) were found to be stable toward moisture and air. Ti(Oi-Pr)2(ACCP)2 and Ti(Oi-Pr)2(HBP)2 were proved to have lower melting points and higher decomposition temperatures. However, these complexes are thermally stable and pyrolysis under an inert atmosphere resulted in incomplete decomposition. Ti(Oi-Pr)2(DPM)2 (DPM=dipivaloylmethane) and Ti(Oi-Pr)2(HFAA)2 (HFAA=hexafluoroacetylacetone) were sublimed substantially during the thermal decomposition. Pyrolysis mechanism of these complexes are dependent on type of β-diketone but removal of Oi-Pr ligands occurs before the decomposition of β-diketonate ligands.