• Natural Product Sciences
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• v.25 no.3
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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 $13.1{\mu}g/mL$.

• Natural Product Sciences
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• v.29 no.1
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• pp.38-41
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• 2023

Two xanthones and 4-phenylcoumarins were isolated from the twigs of Mesua beccariana (Baill.) Kosterm. Among them, one new xanthone, beccarianin A (1), along with 7-isoprenyl-jacareubin (2), mammea A/AA cyclo F (3), and mammea A/BA cyclo F (4). These structures were determined by spectrometric and spectroscopic methods, HRESIMS data, NMR, and UV spectra. Two xanthones (1-2) and two 4-phenylcoumarins (3-4) were evaluated for their cytotoxic effect on the HeLa cells. Compound 1 showed active activity (IC₅₀ = 8.2 µM), and compounds 3-4 showed moderate activity (IC₅₀ = 12.3 and 15.6 µM, respectively).

• Natural Product Sciences
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• v.26 no.1
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• pp.79-82
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• 2020

A new cinnamyl acid derivative, willughbein A (1) along with pinoresinol (2), alyterinate A (3), and scopoletin (4), were isolated from the roots of Willughbeia coriacea Wall. The structure of 1 has been determined based on HRESIMS, 1D, and 2D NMR spectral data. All of the isolates were evaluated for their cytotoxicity against three human cancer cells (HeLa, T47D, MCF-7, and P-388). Compound 3 showed moderate activity against P-388 cells with an IC₅₀ value of 3.04 ㎍/mL.

• Journal of the Korean Chemical Society
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• v.52 no.5
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• pp.523-529
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• 2008

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2546-2552
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• 2012

A novel biguanide-functionalized $Fe_3O_4/SiO_2$ magnetite nanoparticle with a core-shell structure was developed for utilization as a heterogeneous organosuperbase in chemical transformations. The structural, surface, and magnetic characteristics of the nanosized catalyst were investigated by various techniques such as transmission electron microscopy (TEM), powder X-ray diffraction (XRD), vibrating sample magnetometry (VSM), elemental analyzer (EA), thermogravimetric analysis (TGA), $N_2$ adsorption-desorption (BET and BJH) and FT-IR. The biguanide-functionalized $Fe_3O_4/SiO_2$ nanoparticles showed a superpara-magnetic property with a saturation magnetization value of 46.7 emu/g, indicating great potential for application in magnetically separation technologies. In application point of view, the prepared catalyst was found to act as an efficient recoverable nanocatalyst in nitroaldol and domino Knoevenagel condensation/Michael addition/cyclization reactions in aqueous media under mild condition. Additionally, the catalyst was reused six times without significant degradation in catalytic activity and performance.

• Natural Product Sciences
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• v.27 no.1
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• pp.45-48
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• 2021

One new compound, macasiamenene V (1), and two known stilbenes (2-3) were isolated from Macaranga inermis Pax & K.Hoffm leaves. The structure of 1 was fully assigned based on the information on high-resolution MS and (1D, 2D) NMR spectra. The cytotoxic of compounds 1-3 was evaluated against 4T1 and HeLa cells. Compounds 2-3 showed high activity against HeLa cells with an IC50 value of 1.09 and 0.88 ㎍/mL, respectively.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3805-3808
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• 2011

• Journal of the Korean Chemical Society
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• v.56 no.1
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• pp.78-81
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• 2012

Aromatic 2,3-diazabuta-1,3-dienes in glacial acetic acid with isothiocyanate in the presence of catalyst $TiCl_4$ at room temperature produced via criss-cross cycloaddition reactions the corresponding perhydro[1,2,4]triazolo[1,2-a][1,2,4] triazole-1,5-dithiones in relatively high yields and short reaction time.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1057-1060
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• 2009

Boric acid ($BO_3H_3$) is an inexpensive, efficient and mild catalyst for the synthesis of 2,4,5-triaryl-1H-imidazoles in excellent yields from the one-pot three-component condensation of benzil/benzoin, an aldehydes and ammonium acetate in aqueous media under ultrasound at room temperature. The remarkable advantages offered by this method are green catalyst, mild reaction conditions, simple procedures, much faster reactions and excellent yield of products.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1355-1360
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• 2013

We have developed a new multifunctional material, 4,4',4"-tris(4-naphthalen-2-yl-phenyl)amine (2-TNPA), which can be used as a blue-emitting and hole-transporting material in organic light-emitting diodes (OLEDs), as well as a donor material in organic solar cells (OSCs) and an active material in organic thin-film transistors (OTFTs). The OLED device doped with 3% 2-TNPA shows a maximum current efficiency of 3.0 $cdA^{-1}$ and an external quantum efficiency of 3.0%. 2-TNPA is a more efficient hole-transporting material than 4,4'-bis[N-(naphthyl-N-phenylamino)]biphenyl (NPD). Furthermore, 2-TNPA shows a power-conversion efficiency of 0.39% in OSC and a field-effect mobility of $3.2{\times}10^{-4}cm^2V^{-1}s^{-1}$ in OTFTs.