Self-threading of a poly(ethylene glycol) chain in a cyclodextrin-ring: control of the exchange dynamics by chain length.

Poly(ethylene glycol) (PEG)-substituted cyclodextrins (CDs) with different chain lengths have been synthesized. PEG-substituted CDs formed self-threading complexes in aqueous solutions, and the conformational exchange dynamics between self-threading and dethreading could be regulated by its chain length.

Nanoacorns: anisotropically phase-segregated CoPd sulfide nanoparticles.

The anisotropically phase-segregated CoPd sulfide nanoparticles, named "CoPd nanoacorns", were spontaneously generated by reducing the corresponding metal precursors with 1,2-hexadecanediol in the presence of various alkanethiols. The CoPd nanoacorn consisting of crystalline Co9S8 and amorphous PdSx phases with the Co9S8 (001) plane at their interface was found to spontaneously form through the anisotropic growth of the Co9S8 phase after the generation of PdSx nanoparticles.

Simultaneous determination of D-glucose and 3-hydroxybutyrate by chemiluminescence detection with immobilized enzymes in a flow injection system.

A chemiluminometric flow-through sensor for the simultaneous determination of glucose (Glu) and 3-hydroxybutyrate (HB) in a single sample has been developed. Coimmobilized 3-hydroxybutyrate dehydrogenase/NADH oxidase/peroxidase, a support material, and coimmobilized glucose dehydrogenase/NADH oxidase/peroxidase were packed sequentially in a transparent PTFE tube. The tube was then placed in front of a photomultiplier tube as a flow cell. A two-peak recording was obtained by one injection of the sample solution. The peak heights of the first and second peaks were dependent on the concentrations of HB and Glu, respectively. The calibration graphs for HB and Glu were linear at 0.05-10 and 0.1-30 microM, respectively. The maximum sample throughput was 30 h(-1). The sensor was stable for two weeks.

Widespread occurrence of syn-alkane-6,8-diols in the flowers of the compositae.

Ten tabular- and eight ligulate-flowers and seven flower-heads from twenty-two species of Compositae were investigated for their alkanediol constituents. All of the flowers contained alkanediols in small amounts suggesting their widespread occurrence in these flowers. Twelve alkanediols were identified as syn(R,S and/or S,R)-C(21)-, C(23)-, C(25)-, and C(27)--C(35)-alkane-6,8-diols among which syn-hentriacontane-6,8-diol occurred abundantly in many of the flowers.