• 대한화학회지
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• 제56권1호
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• pp.68-73
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• 2012

In the present study, we have synthesized novel Isopropyl 2-(4-substitutedbenzylidene)-5-methyl-3-oxo-7-phenyl-3,7-dihydro-2H-thiazolo[3,2-a]-pyrimidine-6-carboxylate derivatives (6a-j). Elemental analysis, IR, $^1H$ NMR and mass spectral data elucidated structure of newly synthesized compounds. The newly synthesized compounds were screened for antiinflammatory and anti microbial studies. Their biological activity data of the 10 compounds indicates that two compounds posses potent anti-inflammatory and five have antimicrobial activities.

• Bulletin of the Korean Chemical Society
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• 제35권3호
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• pp.737-742
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• 2014

The vibronic emission spectra of isomeric trimethylbenzyl radicals were reassigned based on substituent effect on electronic transition energy as well as ab initio calculation of the benzyl radical. The electronic transition energy of three isomeric jet-cooled trimethylbenzyl radicals produced by corona discharge of 1,2,3,5-tetramethylbenzene were analyzed using the empirical data of three isomeric methylbenzyl radicals. Calculated data were obtained by summing up the shifts measured from methylbenzyl radicals as well as taking the position and alignment of substituents on the benzene ring into account. The revised assignments show better agreement with observation, and rationalize the validity of the model developed to explain the substituent effect on electronic transition energy of benzyl radicals.

• Mass Spectrometry Letters
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• 제3권3호
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• pp.63-67
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• 2012

The need of heavy and unconventional crude oil as an energy source is increasing day by day, so does the importance of petroleomics: the pursuit of detailed knowledge of heavy crude oil. Crude oil needs techniques with ultra-high resolving capabilities to resolve its complex characteristics. Therefore, ultra-high resolution mass spectrometry represented by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has been successfully applied to the study of heavy and unconventional crude oils. The analysis of crude oil with high resolution mass spectrometry (FT-ICR MS) has pushed analysis to the limits of instrumental and methodological capabilities. Each high-resolution mass spectrum of crude oil may routinely contain over 50,000 peaks. To visualize and effectively study the large amount of data sets is not trivial. Therefore, data processing and visualization methods such as Kendrick mass defect and van Krevelen analyses and statistical analyses have played an important role. In this regard, it will not be an overstatement to say that the success of FT-ICR MS to the study of crude oil has been critically dependent on data processing methods. Therefore, this review offers introduction to peotroleomic data interpretation methods.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2338-2343
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• 2007

Under the framework of green chemistry, an efficient and extremely fast procedure for the synthesis of 5a-h through four-step procedure starting from 2-arylidenetetralin-1-one 1a-d under microwave irradiation is described. A considerable increase in the reaction rate has been observed with better yield. The structures of the synthesized compounds have been characterized on the basis of their elemental analysis and spectral data. Synthesized compounds 5a-h was evaluated for their antimicrobial activity. Some of the compounds exhibited appreciable activity.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.2139-2142
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• 2011

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3343-3347
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• 2011

A simple efficient and neat synthesis of ${\alpha}$-hydroxy phosphonates has been accomplished from aromatic/heterocyclic aldehydes and diethyl phosphite using $KHSO_4$ as a catalyst under solvent-free conditions at ambient temperature. These compounds are characterized by spectral and analytical data and tested for their anti-oxidant activity.

• Bulletin of the Korean Chemical Society
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• 제13권5호
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• pp.504-507
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• 1992

fac-RuH(NO)(ttp) is fluxional in the range between 180 K and 303 K. The structures involved in this fluxional process are found to be a mixture of two square pyramids and a trigonal bipyramid from the low temperature NMR spectra and the line shape analysis using DNMR 3 program and the activation parameters of this process were determined by using the simulated data. The mechanism of this fluxional process is proposed to be a pathway known as Turnstile Rotation.

• Natural Product Sciences
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• 제28권1호
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• pp.6-12
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• 2022

Five sesquiterpenoids, 7-epi-eudesm-4(15)-ene,1β,6α-diol (1), 7-epi-eudesm-4(15)-ene,1β,6α-diol (2), saniculamoid D (3), aphanamol I (4), and 4β,10α-dihydroxyaromadendrane (5), were isolated from the stem bark of Aglaia grandis. The compounds' (1-5) chemical structures were identified by spectroscopic data including, IR, NMR (¹H, ¹³C, DEPT 135°, HMQC, HMBC, ¹H-¹H COSY), and HRTOFMS, as well as by comparing with the previously reported spectral data. Therefore, this study described the structural elucidation of compounds 1-5 and evaluated their cytotoxic effects against Hela cervical and B16F10 melanoma cells for the first time, but no significant result was discovered.

• Natural Product Sciences
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• 제27권3호
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• pp.172-175
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• 2021

Sesbagrandiflorain F (1), a novel 2-arylbenzofuran, and two more 2-arylbenzofurans (2-3), were isolated from the stem bark of Sesbania grandiflora L. Based on information HRESIMS data, 1D, and 2D NMR spectra, the structure of 1 was fully assigned. Compounds 1-3 were tested for cytotoxicity in MCF-7 and HeLa cells. Compounds 1 and 3 showed moderate activity against MCF-7 cells with an IC₅₀ value of 2.68 and 4.08 ㎍/mL, respectively. Conversely, all of the isolates were inactive towards HeLa cells.

• Natural Product Sciences
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• 제25권3호
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• pp.244-247
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• 2019

A new isoprenylated stilbene, flavestinK (1) together with two known isoprenylated stilbenes, flavestin B (2), flavestin G (3), and two isoprenilated flavanones, 4-O-methyl-8-isoprenylnaringenin (4) and 8-isoprenyl-5,7-dihydroxyflavanone (5) were isolated from the leaves of Macaranga recurvata Gage. All of the structures have been determined based on HRESIMS, 1D and 2D NMR spectral data. All of the isolated compounds were evaluated for their cytotoxicity against three human cancer cells (HeLa, T47D and WiDr). Compound 1 showed higher activity than doxorubicin against HeLa cells with $IC_{50}$ value of $13.1{\mu}g/mL$.