Antiproliferative effects of zerumbone-pendant derivatives on human T-cell lymphoid cell line Jurkat cells

Zerumbone is the major component of the essential oil of wild ginger, Zingiber zerumbet Smith. It is not only highly reactive but also has diverse bioactivities. Those effects derive from two conjugated double bonds of zerumbone and a carbonyl group in between, and we had already established a synthetic scheme for zerumbone-pendant derivatives without disturbing the conjugation system. Herein, twelve conjugates with salicylic acid or various benzoic acid derivatives were synthesized for evaluations of their antiproliferative effects on Jurkat cells as salicylic acid is bioactive and has a carboxylic group for coupling. Most of them resulted in IC₅₀ values as low as 1–10?μM, validating the utility of this activity-conserving strategy.     

Positivity of the Density for Rough Differential Equations

Due to recent developments of Malliavin calculus for rough differential equations, it is now known that, under natural assumptions, the law of a unique solution at a fixed time has a smooth density function. Therefore, it is quite natural to ask whether or when the density is strictly positive. In this paper we study this problem from the viewpoint of Aida–Kusuoka–Stroock’s general theory.

     

Tetrathiafulvalene-Inserted Diphenoquinone: Synthesis,Structure, and Dynamic Redox Property

A new tetrathiafulvalene (TTF) derivative is synthesized, which is substituted with two phenoxy radicals on one 1,3-dithiole ring, and may have either open-shell diradical or closed-shell extended-quinoidal ground states. X-ray single crystal analysis and NMR measurements prove that this molecule has a closed-shell extended quinoidal structure both in the solid state and in solution. DFT calculations show the donor–acceptor electronic properties of this molecule with a well-separated HOMO–LUMO distribution and a small HOMO–LUMO energy gap. Because of this donor–acceptor character, this molecule gives both the dication and the dianion species by electrochemical oxidation and reduction. Furthermore, during the redox process between the neutral and dication states, this molecule exhibits unique changes in the cyclic voltammogram upon repeating the cycles or varying the scan rate. The observed electrochemical behavior is explained by the conformational changes in the electrochemically generated species, thus indicating that this molecule is classified as a dynamic redox system.     

Thermodynamic aspects of the heterogeneous structure of “golf-ball-like” polymer particles

Recently, we found that “golf-ball-like” polystyrene (PS)/poly(butyl acrytlate) composite particles could be produced by seeded emulsion polymerization of butyl acrylate with PS seed particles. In this article, the theoretical and experimental thermodynamic instabilities of the golf-ball-like structure are discussed and are compared with core-shell and hemispherical morphologies. Received: 2 February 1999 Accepted in revised form: 3 June 1999     

Quantitative proteomic analysis of chromatin-associated factors

A method to identify and quantify chromatin-associated proteins has been developed and applied to the analysis of changes in chromatin-associated proteins induced by Myc oncoprotein expression in human B lymphocytes. Chromatin-enriched fractions were isolated by differential detergent/salt extraction and analyzed by ICAT reagent labeling, multi-dimensional chromatography and tandem mass spectrometry. Many known chromatin-associated regulatory factors were identified and quantified. The method will be widely applicable to various biological systems and reveal changes in chromatin-associated regulatory factors that underlie biological phenomena.     

Separate vaporisation of boric acid and inorganic boron from tungsten sample cuvette-tungsten boat furnace followed by the detection of boron species by inductively coupled plasma mass spectrometry and atomic emission spectrometry (ICP-MS and ICP-AES)

Utilising extremely different vaporisation properties of boron compounds, the determination procedures of volatile boric acid and total boron using tungsten boat furnace (TBF) ICP-MS and TBF-ICP-AES have been investigated. For the determination of volatile boric acid by TBF-ICP-MS, tetramethylammonium hydroxide (TMAH, Me₄NOH) was used as a chemical modifier to retain it during drying and ashing stages. As for the total boron, not only non-volatile inorganic boron such as boron nitride (BN), boron carbide (B₄C), etc. but also boric acid (B(OH)₃) was decomposed by a furnace-fusion digestion with NaOH to produce sodium salt of boron, a suitable species for the electrothermal vaporisation (ETV) procedure. The proposed method was applied to the analysis of various standard reference materials. The analytical results for various biological and steel samples are described.     

Reactions of tris(2‐pyridyl)phosphine oxides with electrophiles: Formation of 5‐substituted 2,2′‐bipyridyls

The reaction of tris(2‐pyridyl)phosphine oxides with benzeneselenenyl chloride in methanol gave the corresponding 5‐phenylseleno‐2,2′‐bipyridyls together with a small amount of 2,2′‐bipyridyls. Similarly, the reaction with arenesulfenyl chlorides in aqueous acetonitrile afforded two kinds of coupling products, 5‐phenylthio‐2,2′‐bipyridyls and 2,2′‐bipyridyls. While in the reaction with arenesulfinyl chlorides in aqueous acetonitrile, four corresponding bipyridyl derivatives, 2,2′‐bipyridyls, 5‐arylthio‐2,2′‐bipyridyls, 5‐arylsulfinyl‐2,2′‐bipyridyls, and 5‐arylsulfonyl‐2,2′‐bipyridyls, were formed. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:72–81, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10085