Shimoda K.,Oita University |
Imai H.,Okayama University of Science |
Mandai T.,Kurashiki University of Science and the Arts |
Hamada H.,Okayama University of Science
Natural Product Communications | Year: 2012
Time course experiment revealed that cultured plant cells of Eucalyptus perriniana regioselectively glucosylated silybin to silybin-23-β-D- glucoside in up to 70% yield.
Arai M.A.,Chiba University |
Tateno C.,Chiba University |
Koyano T.,Temko Corporation |
Kowithayakorn T.,Khon Kaen University |
And 2 more authors.
Organic and Biomolecular Chemistry | Year: 2011
The aberrant hedgehog (Hh)/GLI signaling pathway causes the formation and progression of a variety of tumors. We recently constructed a cell-based screening system to search for Hh/GLI signaling inhibitors from natural resources. Using our screening system, Adenium obesum was found to include Hh/GLI signaling inhibitors from our tropical plant extract libraries. Bioassay-guided fractionation of this plant extract led to the isolation of 17 cardiac glycosides (1-17), including 3 new compounds (4, 9, 16). These compounds showed strong inhibitory activities, especially the IC50 of 17 is 0.11 μM. The inhibition of GLI-related protein expression with 3, 9, 11, 15 and 17 was observed in human pancreatic cancer cells (PANC1), which express Hh/GLI components aberrantly. The expressions of GLI-related proteins PTCH and BCL2 were clearly inhibited. These compounds also showed selective cytotoxicity against two cancer cell lines, with less effect against normal cells (C3H10T1/2). RT-PCT examinations showed that Ptch mRNA expression by 3, 11, 15 and 17 was inhibited. © 2011 The Royal Society of Chemistry.
Ishikawa M.,Hiroshima University |
Naka A.,Kurashiki University of Science and the Arts |
Yoshizawa K.,Kyushu University
Dalton Transactions | Year: 2016
The synthesis and reactions of 3,4-benzo-1,2-disilacyclobut-3-enes and benzo[1,2:4,5]bis(1,2-disilacyclobut-3-ene)s developed by our group are reported in this review. The palladium-, platinum- and nickel-catalyzed reactions of benzodisilacyclobutenes and benzobis(disilacyclobutene)s with unsaturated compounds afford various types of products. The structures of the products are dependent upon the nature of the transition metal used as a catalyst. The reactions of cis- and trans-benzodisilacyclobutenes with alkenes and alkynes in the presence of a transition-metal catalyst proceed with high stereospecificity to give the respective adducts. The thermal reactions of cis- and trans-benzodisilacyclobutenes with various substrates also proceed stereospecifically to give adducts. The results of theoretical calculations for the platinum-catalyzed reaction of disilacyclobutene with acetylene, the nickel-catalyzed reaction of benzodisilacyclobutene and the thermal reaction of benzobis(disilacyclobutene) are discussed in this review. © The Royal Society of Chemistry 2016.
Yamamoto S.,Kyoto University |
Kusano Y.,Kurashiki University of Science and the Arts
Chemistry Letters | Year: 2016
A method to prepare FePt/PbS core/shell nanoparticles with a controllable PbS thickness (dPbS) based on the reaction of lead oleate and sulfur in the presence of FePt nanoparticles has been developed. It was demonstrated that dPbS can be finely controlled from ca. 0.5 to 4.3nm by adjusting the reaction temperature and/or the time. The resulting FePt/PbS core/shell nanoparticles with various dPbS's showed smaller magnetic anisotropies than those of the pristine FePt nanoparticles. The observed anisotropies were almost constant and independent of dPbS. This result indicates that it is the surface anisotropy and not the interparticle magnetic dipolar interactions that predominantly determines the magnetic properties of the FePt/PbS core/shell nanoparticles. © 2016 The Chemical Society of Japan.
Danno T.,Okayama University |
Nakatsuka D.,Okayama University |
Kusano Y.,Kurashiki University of Science and the Arts |
Asaoka H.,Okayama University |
And 4 more authors.
Crystal Growth and Design | Year: 2013
β-Fe2O3 is the scarce polymorph of Fe 2O3 phases and is transformed easily into α-Fe 2O3 at high temperature. However, its crystal structure and the transformation mechanism to α-Fe2O3 are still unclear because of the difficulty in obtaining monophasic β-Fe 2O3 crystals. We established a synthesis method of the monophasic β-Fe2O3. It was synthesized by a two-step reaction: heating a mixture of Na2SO4 and Fe 2(SO4)3 in air at 250 C to form NaFe(SO 4)2, and subsequent heating the resultant phase with NaCl in air at 500 C. The crystal structure was refined to a bixbyite-type cubic structure (Ia3Ì...) with a = 9.4039(1) Å by the Rietveld method. Single crystalline β-Fe2O3 particles of approximately 1 μm in size were topotactically transformed into single α-Fe 2O3 crystals. Electron diffraction analysis revealed the crystallographic orientation relationships between β-Fe2O 3 and α-Fe2O3 to be  β//α, β// [101Ì...0]α, and β//[1Ì... 21Ì...0]α. © 2013 American Chemical Society.