Sung Chul Shin

Simple preparation of terthiophene-3′-carboxylic acid and characterization of its polymer

Abstract 5,2′-5′,2″-Terthiophene-3′-carboxylic acid (TTCA), a potentially useful starting material for the synthesis of functionalized polyterthiophenes, can be simply prepared by the treatment of 3′-bromothiophene with CuCN in DMF followed by hydrolysis in KOH-ethoxyethanol. TTCA was polymerized on a glassy carbon electrode in a 0.1xa0M Et 4 NClO 4 /dichloromethane solution. The polymer film was characterized with cyclic voltammetry, in situ UV–VIS spectroscopy, in situ conductivity, and chronoabsorptometry. In contrast to many other conducting polymers, the conductivity of the resulting polymer increased even in a state of full oxidation. In addition, the resulting polymer film displayed fast electrochromic switching.

Synthesis of octahedral rhenium cluster chalcobromides Re6X4Br10 and Re6X8Br2 (X = S, Se, Te) by condensation from triangular rhenium bromide Re3Br9

Abstract A new high yield (75–95%) method—condensation of polyhedral clusters—for synthesis of octahedral rhenium cluster compounds Re 6 X 4 Br 10 and Re 6 X 8 Br 2 (X = S, Se, Te) has been developed using triangular cluster rhenium bromide Re 3 Br 9 and lead or cadmium chalcogenides as starting materials. The phases obtained were characterized by chemical analysis and X-ray powder diffraction method, and the cell unit parameters of compounds were found. The crystal structure of Re 6 Te 4 Br 10 was solved by X-ray single crystal analysis. Crystallographic data: triclinic, space group P 1, a = 9.347(2), b = 9.403(4), c = 13.348(4) A , α = 84.46(3), β = 84.64(2), γ = 82.11(2) °, V = 1152.8(6) A 3 , Z = 2, D x = 6.991 g-cm −3 , R(F) = 0.0378, wR(F 2 ) = 0.0906.

Determination of Polyphenol Components of Korean Prostrate Spurge (Euphorbia supina) by Using Liquid Chromatography—Tandem Mass Spectrometry: Overall Contribution to Antioxidant Activity

The Korean prostrate spurge Euphorbia supina is a weed that has been used in folk medicine in Korea against a variety of diseases. Nine polyphenols were characterized for this plant by using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and the results were compared with the literature data. The individual components were validated using the calibration curves of structurally related external standards and quantified for the first time by using the validated method. Correlation coefficients (r 2) were >0.9907. The limit of detection and limit of quantification of the method were >0.028u2009mg/L and 0.094u2009mg/L, respectively. Recoveries measured at 50u2009mg/L and 100u2009mg/L were 76.1–102.8% and 85.2–98.6%, respectively. The total amount of the identified polyphenols was 3352.9u2009±u20092.8u2009mg/kg fresh plant. Quercetin and kaempferol derivatives formed 84.8% of the total polyphenols. The antioxidant activities of the flavonoids were evaluated in terms of 1,1-diphenyl-2-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation-scavenging activity, and the reducing power showed a dose-dependent increase. Cell viability was effectively suppressed at polyphenol mixture concentrations >250u2009mg/L.

Wavelength tuning of light-emitting polyarenes via an m-phenylene interrupting block: π–π* band-gap adjustment of thiophene-based conjugated polymers

The π–π* band gap of thiophene-based conjugated polymers can be adjusted via the insertion of m-phenylene bridges into regularly defined positions.

Flavonoids from Orostachys japonicus A. Berger induces caspase-dependent apoptosis at least partly through activation of p38 MAPK pathway in U937 human leukemic cells.

BACKGROUNDnOrostachys japonicus A. Berger (A. Berger) is commonly used as a folk remedy for cancer therapy. However, the mechanisms of its anti-cancer activity are poorly investigated in human cancer cells. In this study, we investigated whether flavonoids extracted from Orostachys japonicus A. Berger (FEOJ) might have anticancer effects in human leukemia cells, focusing on cell death mechanisms.nnnMATERIALS AND METHODSnU937 human leukemic cancer cells were used.nnnRESULTSnFEOJ induced apoptosis in a dose-dependent manner in human U937 cancer cells. Flow cytometry revealed significant accumulation of cells with sub-G1 DNA content at the concentrations of 200 μg/mL and 400 μg/mL. FEOJ-induced apoptosis was caspase-dependent through loss of mitochondrial membrane potential (MMP, ΔΨm) in human U937 cancer cells, which might be associated with suppression of Bcl-2 and XIAP proteins. FEOJ induced the p38 MAPK signaling pathway, playing at least in part an important role in FEOJ-induced apoptosis.nnnCONCLUSIONSnThis study suggested that FEOJ may induce caspase-dependent apoptosis in human leukemic cells by regulating MMP (ΔΨm) through suppressing Bcl-2 and X-IAP. In addition, the results indicated that upstream p38 MAPK signaling regulates the apoptotic effect of FEOJ. This study provides evidence that FEOJ might have anti-cancer potential for human leukemic cells.

Anthocyanins from the Fruit of Vitis Coignetiae Pulliat Inhibit TNF-Augmented Cancer Proliferation, Migration, and Invasion in A549 Cells

Objective: Anthocyanins belong to a class of flavonoids, exhibiting antioxidant and anti-inflammatory actions have been reported to have anti-cancer effects. Here, we investigated whether anthocyanins can inhibit cancer cell proliferation, invasion, and angiogenesis in human lung cancer A549 cells, which are critically involved in cancer metastasis. Methods: We used anthocyanins from fruits of Vitis coignetiae Pulliat (AIMs) which has been used in Korean folk medicine for the treatment of inflammatory diseases and cancers. We have performed cell proliferation assays, cell invasion assay, gelatin zymography, wound healing assay and western blotting to examine whether anthocyanins can inhibit cancer cell proliferation, invasion, and angiogenesis in A549 cells. Result: AIMs did not inhibit cancer cell proliferation on A549 cells. Also, AIMs suppressed cancer migration, and invasion by supressing MMP-2 and MMP-9 expression. The Immuno-blotting results also revealed that AIMs suppressed the proteins involved in cancer proliferation (COX-2, C-myc, cyclin D1), migration and invasion (MMP-2, MMP-9), anti-apoptosis (XIAP, and c-IAP2), adhesion and angiogenesis (ICAM-1, VEGF). Conclusion: This study demonstrates that the anthocyanins isolated from fruits of Vitis coignetiae Pulliat inhibit cancer proliferation, cancer migration, and invasion that is involve in cancer-metastasis. This study provides evidence that AIMs might have anti-cancer effects on human lung cancer.

Polyterthiophene-bearing pendant organomolybdenum complexes: electropolymerization of erythro-[Mo2(µ-C5H5)2(CO)4{µ-η2∶η2-C(R)C[C4HS(C4H3S-2)2-2,5]}]

Terthiophenes bearing pendant organomolybdenum complexes, erythro-[Mo2(η-C5H5)2(CO)4{µ-η2∶η2-C(R) C[C4HS(C4H3S-2)2-2,5]} (Rxa0=xa0H 1a or Ph 1b) were prepared by reaction of [Mo2(η-C5H5)2(CO)4] with 3′-alkynyl-2,2′∶5′,2″-terthiophenes. The molecular structures of 1a and 1b were identified by spectroscopic methods and X-ray diffraction. Cyclic voltammetry of 1a and 1b showed deposition of electroactive polymeric films on the electrode surface. The absorption spectra of 1a, 1b and their polymer films are presented.