• Natural Product Sciences
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• v.29 no.2
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• pp.83-90
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• 2023

To our knowledge, this is the first study aiming to optimize the extraction conditions of total phenolic compounds (TPC) and total flavonoids contents (TFC) from Argania spinosa leaves using Response Surface Methodology (RSM) with a Box-Behnken design (BBD). The optimal conditions obtained were 5% (w/v) solvent-to-solid ratio, 72.33% ethanol concentration, and 10h ours as an extraction time, which resulted in an extract with maximum TPC (131.63 mg GAE/g dw) and TFC (10.66 mg QE/g dw). Under the optimal extraction conditions, the antioxidant activity of the extracts of leaves of argan tree showed a moderate antiradical capacity of DPPH (IC₅₀ = 0,130 mg/mL) and ABTS (IC₅₀ = 0.198 mg/mL). However, the leaves of argan tree showed a very interesting reducing power of Iron (IC₅₀ = 0.448 mg/ml) which is similar to that of the ascorbic acid (IC₅₀ = 0.371 mg/mL).

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1575-1578
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• 2011

Antimony trichloride (SbCl3) was demonstrated to be an effective catalyst for the cyanosilylation of a wide variety of carbonyl compounds under solvent-free conditions. The reactions proceeded smoothly at room temperature to afford the corresponding cyanosilylethers in good to excellent yields.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3156-3158
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• 2010

Stable and non-hygroscopic polystyrene supported aluminium triflate (Ps-$Al(OTf)_3$), which is prepared easily from cheap and commercially available compounds was found to be an environmentally friendly heterogeneous catalyst for Friedel-Crafts acylation of arenes using acid chlorides in the absence of solvent under mild reaction conditions. The catalyst can be reused up to five times after simple washing with dichloromethane.

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.220-224
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• 2004

• Proceedings of the Korean Magnestics Society Conference
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• 2013.05a
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• pp.68-69
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• 2013

• Journal of Life Science
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• v.18 no.2
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• pp.213-219
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• 2008

Flavonoids in pine needles are known to be effective scavengers of free radical. Especially, proanthocyanidin, a kind of flavonoids possesses cardiovascular protection and antioxidative activities. Here, we evaluated proanthocyanidin contents in total polyphenolic compounds of pine needle extracts prepared by using hot water, ethanol, hexane or sub-supercritical $CO_2$. Analyses of total polyphenolic compounds and proanthocyanidin in each extracts indicated that hot water extract contained the highest concentrations, but sub-supercritical extract contained the lowest concentrations. On the other hand, evaluation of proanthocyanidin contents in total polyphenolic compounds in each extracts showed that sub-supercritical extract possessed the highest content, but hot water extract possessed the lowest content. These results indicate that extracts containing high concentrations of both total polyphenolic compounds and proanthocyanidin could be obtained by using hot water or ethanol extractions. Furthermore, extract containing high content of proanthocyanidin out of total polyphenolic compounds could be achieved by using sub-supercritical extraction. Measurement of antioxidative activities of extracts showed that hot water extract possessed the highest activity. In this study, we prepared extracts from pine needles by four different methods and evaluated the antioxidative compounds in extracts that could be used for effective components of functional food products.

• Korean Journal of Plant Resources
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• v.33 no.2
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• pp.63-72
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• 2020

Fermented complex from garlic and nine medicinal plants were developed as a natural whitening material. Tyrosinase inhibition activity was determined and four active compounds were isolated. The nutritional components of fermented garlic complex (FGC) were analyzed to confirm the applicability as a functional food material. Tyrosinase inhibitory effect of FGC was 88.6%. Methanol extract was partitioned with EtOAc, n-BuOH and H₂O. From the EtOAc fraction (47 g), which showed the highest yield, active fractions were separated by repeated TLC, silica gel and ODS column chromatography to isolate active compounds. The chemical structures of the isolated compounds were analyzed by NMR and MS spectra. Phenylpropanoid compounds of 2,4,5-trihydroxy-benzenepropanoic acid (1) (1.9 mg) and 2,3,5-trihydroxy-benzenepropanoic acid (2) were confirmed. In addition, 2,4-dihydroxy-hydrocinnamic acid (3) (3.3 mg) and (+)sesamin (4) (6.1 mg) were isolated. These compounds will be useful as index compounds or functional compounds in FGC.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.78-89
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• 2020

Tomato fruit quality is determined by the contents of various functional metabolites in addition to fruit appearance. To develop tomato cultivars with higher amounts of functional compounds, an efficient quantification method is required to identify the natural variations in the compounds in the tomato germplasm. In this study, we investigated tomato varieties, which included 23 inbred lines and 12 commercial F₁ cultivars, for their contents of seven watersoluble vitamins (vitamin C, vitamins B1, B2, B3, B5, B6, and B9) and five polyphenolic compounds (quercetin, rutin, kaempferol, myricetin, and naringenin chalcone). The results of high performance liquid chromatography and liquid chromatography-mass spectrometry showed that vitamin C and naringenin chalcone were the major water-soluble vitamins and polyphenolic compounds, respectively, and their abundance was highly variable depending on the cultivar. By contrast, the contents of vitamin B1, quercetin, and kaempferol were lowest among the cultivars. With regard to the relationship between metabolic compounds and fruit characteristics, a significant association was found in fruit size, indicating that cherry tomato varieties contain higher amounts of the compounds compared to large fresh-type varieties. However, no direct association was detected in fruit color, except for naringenin chalcone. The results of this study provide new insights on the quantification of metabolic compounds and the selection of breeding materials, which are prerequisites for the development of functional tomato varieties.

• Journal of the Microelectronics and Packaging Society
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• v.30 no.4
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• pp.17-31
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• 2023

Amidst escalating global warming fueled by indiscriminate fossil fuel consumption, concerted efforts are underway worldwide to mitigate atmospheric carbon dioxide (CO₂) levels. Electrochemical CO₂ reduction technology is recognized as a promising and environmentally friendly approach to convert CO₂ into valuable hydrocarbon compounds, deemed essential for achieving carbon neutrality. Copper, among the various materials used as CO₂ reduction electrodes, is known as the sole metal capable of generating C₂₊ compounds. However, low conversion efficiency and selectivity have hindered its widespread commercialization. This review highlights diverse research endeavors to address these challenges. It explores various studies focused on utilizing copper-based electrodes for CO₂ reduction, offering insights into potential solutions for advancing this crucial technology.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1554-1558
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• 2011

A novel and efficient method for the synthesis of 2,3-dihydrofurans bearing a variety of substituents on the dihydrofuran ring was achieved by the reaction of cyclic diazodicarbonyl compounds with styrene and vinyl acetate. The key strategy was AgBF$_4$/[Bmim]BF$_4$-catalyzed [3+2] cycloaddition. The synthesized dihydrofurans with an acetate group were further converted to the corresponding 3-acylfurans.