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label: url

en: Recent Advances in Endoscopic Molecular Imaging of Gastrointestinal Cancer

ja: 総説 がんを標的とした内視鏡分子イメージングの新展開

en: OPTRONICS

ja: 月刊 オプトロニクス


en: 新しいホスホノアミダート型プロドラッグの開発

ja: 新しいホスホノアミダート型プロドラッグの開発

en: Farumashia

ja: ファルマシア


en: Development of Novel Functional Molecules Based on the Molecular Structure Characteristics of Diketopiperazines

ja: ジケトピペラジンの分子構造特性を基盤とする機能性分子の創製

en: This article focuses on our investigation of the molecular structure characteristics of diketopiperazines (DKPs), and application of these findings to the development of novel functional molecules. DKPs bearing a benzyl moiety are known to adopt a folded conformation, in which the benzyl moiety is folded over the DKP ring. In order to investigate the driving force behind the folded conformation, we synthesized DKPs bearing a benzyl moiety with different para-substituents, and demonstrated that the folded conformation likely arose from intramolecular CH/ϖ interactions, based on the electronic effects of para-substituents on the benzyl group in H NMR spectroscopy. On the other hand, N4-methylation of DKPs bearing a benzyl moiety was found to change their folded conformation to an extended conformation, based on single crystal X-ray crystallography and H NMR spectroscopy analysis. Next, we attempted to synthesize both hydroxamate-type siderophores containing the DKP ring: rhodotorulic acid and erythrochelin. Facile synthesis of rhodotorulic acid and its N,N'-dimethylated derivative was achieved by microwave-assisted cyclization of the corresponding dipeptide precursors. Interestingly, N,N'-dimethylated rhodotorulic acid was found to be more soluble in various organic solvents than rhodotorulic acid. Moreover, erythrochelin was synthesized for the first time, and its metal-chelating ability with not only Fe(III) but also Mg(II) was confirmed based on electrospray ionization mass spectrometry (ESI-MS) analysis. Finally, we synthesized DKPs bearing a primary amino group, and found that they could catalyze the asymmetric aldol reaction between hydroxyacetone and p-nitrobenzaldehyde.

en: Journal of the Pharmaceutical Society of Japan

ja: 薬学雑誌


en: Chemistry of 2.5-Diketopiperazine and its Bis-lactim Ether: a Brief Review

en: 2,5-Diketopiperazines have attracted much attention because of their biological activities and molecular structure characteristics. Bis-lactim ethers derived from these 2,5-diketopiperazines include well-known organic molecules such as Schöllkopf chiral auxiliaries, which are used in asymmetric synthesis of -amino acids. In this article, we briefly discuss the chemistry of both heterocyclic compounds.

en: Heterocycles

ja: Heterocycles


en: 化学レビュー:多彩に機能するジケトピペラジン

ja: 化学レビュー:多彩に機能するジケトピペラジン

en: 化学

ja: 化学